Three cluster randomised controlled trials in Portugal, Czechia and the United Kingdom to test the effectiveness and cost-effectiveness of an augmented social play intervention in schools to support real- world connection and sense of belonging (Lina trial protocol)

Three cluster randomised controlled trials in Portugal, Czechia and the United Kingdom to test the effectiveness and cost-effectiveness of an augmented social play intervention in schools to support real- world connection and sense of belonging (Lina trial protocol) | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Study protocol Three cluster randomised controlled trials in Portugal, Czechia and the United Kingdom to test the effectiveness and cost-effectiveness of an augmented social play intervention in schools to support real- world connection and sense of belonging (Lina trial protocol) Tamanna Malhotra, Onaiza Qureshi, Adam Barnard, Victoria Bird, and 15 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8595707/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 7 You are reading this latest preprint version Abstract • Background: Mental ill-health and loneliness represent major challenges for today’s youth, exacerbated by unprecedented societal demands, including concurrent socialisation in physical and digital worlds. A strong sense of belonging can buffer against these challenges, and in adolescents is largely constituted in schools. Augmented Social Play (ASP) involves smartphone-led cooperative face-to-face gameplay which integrates immersive storytelling, augmented reality, and evidence-based psychology to strengthen belonging. Building on this foundation, Lina is a multi-session intervention designed for classroom-based delivery during routine school lessons. • Methods: Three parallel hybrid type II cluster pragmatic Randomised Controlled Trials will be conducted in secondary schools in Czechia, Portugal and the UK. The trials will examine the effectiveness of Lina - compared to standard lessons - in strengthening classroom belonging, reducing symptoms of mental ill-health and improving wellbeing, loneliness and stigma. 40 classes of students whose modal age is 12-13 years will participate in each country. Effectiveness will be examined on completion of Lina and after 6-months, using the student-report Delaware School Climate Survey, the Social Anxiety Scale for Adolescents, the Patient Health Questionnaire-8, the Social Awareness subscale of the Social-Emotional Learning Edition of the Strengths and Difficulties Inventory System, the WHO-5 Well-being Index, the UCLA Loneliness Scale and a tailored version of the Peer Mental Health Stigmatisation Scale-Revised. To examine cost-effectiveness, quality of life will be measured in a corresponding manner, using the Child Health Utility 9D and the EQ-5D-Y-3L, and analysed alongside bespoke resource-use inventories, completed via teachers and/or school records. An embedded developmental evaluation of implementation will draw on researcher observations of Lina , teacher-reported Feasibility, Acceptability and Appropriateness of Intervention questionnaires and teacher focus groups. A second developmental phase of implementation evaluation will follow the effectiveness trial, while control classes do Lina with their teachers. An integrated qualitative evaluation will examine students’ experiences of Lina using individual interviews and focus groups, including a particular focus on students with characteristics that put their sense of belonging at risk. • Discussion: Findings will speak to the potential impact of Lina on youth mental health. They will also inform Lina implementation guidance for diverse national and international school contexts. • Trial Registry Information: This trial is prospectively registered with ISRCTN (Identifier: ISRCTN11613092), registered on 15 September 2025, https://doi.org/10.1186/ISRCTN11613092 Adolescent mental health Classroom belonging Loneliness Augmented social play School-based intervention Cluster randomised controlled trial Digital health E-health Structured summary Item Description Primary Registry and Trial Identifying Number {4} ISRCTN (Identifier: ISRCTN11613092, registered on 15 September 2025. https://doi.org/10.1186/ISRCTN11613092 Secondary Identifying Numbers Not Applicable Source(s) of Monetary or Material Support Horizon Europe (101080665) and UK Research and Innovation Primary Sponsor and contact information {3b} University of Birmingham Science, Technology, Engineering and Mathematics Committee University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom +44 (0)121 414 3344 [email protected] Role of sponsor and funder {3c} None Contact for Public Queries [email protected] Contact for Scientific Queries Prof. Kate Anne Woodcock Professor of Applied Clinical Psychology University of Birmingham, School of Psychology 52 Pritchatts Road, Edgbaston, Birmingham, B15 2SA Tel: +44 (0)121 414 6036 Public Title Evaluating social connection and belonging in schools: Protocol for three randomised controlled trials of Lina , a digital intervention in Portugal, Czechia and the United Kingdom Scientific title Three cluster randomised controlled trials in Portugal, Czechia and the United Kingdom to test the effectiveness and cost-effectiveness of an augmented social play intervention in schools to support real-world connection and sense of belonging ( Lina trial protocol) Countries of Recruitment United Kingdom, Czech Republic (Czechia), Portugal Health Condition(s) or Problem(s) Studied Sense of belonging Intervention(s) A classroom-based group intervention utilising a augmented social play application ( Lina ) to enhance a sense of belonging, connectedness and mental health literacy among young people Key Inclusion and Exclusion Criteria Inclusion criteria: A registered school in the UK, Portugal and Czechia enrolling students in grades 7-9 Students aged 12-13 in UK and Czechia and 12-15 years in Portugal Exclusion criteria: Young people whose parent or guardian explicitly requests for them to be opted out of the trial Study Type Three cluster randomised, parallel group-controlled trial in schools across Portugal, Czechia and United Kingdom, Date of First Enrollment (planned) 22/09/2025 Sample Size A total of 880 young people to be recruited per country, assuming an average cluster size of 22 per class (with a drop-out rate of 20%), 40 classes per country, thus giving a total sample size of 880 per country. Primary outcome(s) Sense of belonging/class climate measured by Delaware School Climate Survey- Student (DSCS-S) at baseline, post-intervention (8-10 weeks) and at follow-up (6 months) Key Secondary outcome(s) General wellbeing index, measured by WHO-5 at baseline, post-intervention (8-10 weeks) and at follow-up (6 months) Depression symptom severity, measured by Patient Health Questionnaire-8 at at baseline, post-intervention (8-10 weeks) and at follow-up (6 months) Level of social anxiety, measured by Social Anxiety Scale for Adolescents (SAS-A) at baseline, post-intervention (8-10 weeks) and at follow-up (6 months) Level of loneliness, measured by the UCLA Loneliness Scale for Children at baseline, post-intervention (8-10 weeks) and at follow-up (6 months) Level of social awareness measured by the Social Emotional Learning Scale-brief version – SSIS SELb (social awareness subscale) at baseline, post-intervention (8-10 weeks) and at follow-up (6 months) Level of mental health stigma measured by the Peer Mental Health Stigmatisation Scale Revised - PMHSS-R (stigma awareness subscale) at baseline, post-intervention (8-10 weeks) and at follow-up (6 months) Youth quality of life measured by the EQ-5D-Y-3L at baseline, post-intervention (8-10 weeks) and at follow-up (6 months) Quality-adjusted life years for adolescents measured by the Child Health Utility - CHU-9D at baseline, post-intervention (8-10 weeks) and at follow-up (6 months) Ethics Review UK - Approved 06/05/2025 Science, Technology, Engineering and Mathematics Committee University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom +44 (0)121 414 3344 [email protected] ) Ref: ERN_3004-May2025 PT - Approved 08/09/2025 Comissão de Ética e Deontologia da Faculdade de Psicologia Faculdade de Psicologia, Alameda da Universidade, Lisboa, 1649-013, Portugal +351 217 943 655 [email protected] Ref: N/A CZ - Approved 18/09/2025 Etická Komise pro výzkum Masarykovy Univerzity Research Ethics Committee at Masaryk University, Masarykova Univerzita, Žerotínovo nám. 617/9, Brno 602 00, Česká republika, Brno, 602 00, Czech Republic +420 549 49 6290 [email protected] Ref: EKV-2022-090 Individual Trial Participant Data sharing statement De-identified datasets will be available after publication of the primary trial results in alignment with the ethics guidelines for approval in each country. Introduction Background and rationale {9a} Background Poor mental health and social isolation are increasing among young people (1). Belonging – feeling connected to and accepted by others through supportive interpersonal relationships has been shown to be an important factor in improving mental health and overcoming loneliness in adolescent populations (2,3). A greater sense of school belonging has been associated with a wide array of personal and social benefits including increased psychological wellbeing (4) and reduced instances of school violence, truancy, mental illness, and bullying (5–7). There is, however, a lack of evidence-based interventions addressing belonging, particularly in schools, where socialisation plays a distinct and key role (8). Evidence-based school interventions could therefore be implemented to promote belonging, making use of an opportunistic target and potentially improving outcomes for adolescents (9). Digital technologies offer enormous potential for adolescent health promotion and management (10,11). The ASP-Belong programme of research has developed Lina, a novel intervention whose feasibility has been established through a proof-of-concept prototype (12,13). Lina uses smartphones to deliver an in-person group experience, in a classroom, that combines immersive storytelling, augmented reality, collaborative gameplay and evidence-based psychotherapeutic techniques to strengthen sense of belonging within the classroom . Lina is the first full-scale version of a new intervention format - Augmented Social Play - which shares the same key ingredients but can be abstracted to different in-person group settings. Lina is a multi-session intervention that is delivered within the context of routine school lessons. Rationale Whilst feasibility has been evidenced through previous work, the effectiveness of the intervention is yet to be established. The current trial is therefore the next step in developing Lina and demonstrating its effectiveness on a variety of wellbeing and mental health outcomes, but primarily on sense of belonging. The trial and embedded implementation evaluation will give definitive answers as to how effective this novel intervention is across three national contexts. It will also produce understanding about the best ways to implement the intervention into routine school activities across a number of different contexts, and about young people's lived experiences of L ina , with a particular focus on those who face additional vulnerabilities to poor mental health. Explanation for the choice of comparator {9b} There is no established, widespread school intervention to enhance sense of belonging. Therefore, control classes will continue with standard school activities (i.e., treatment as usual). This comparison offers the most relevant basis for informing educational and policy decisions. Objectives {10} Research aim The primary aim of the trials is to assess the effectiveness of Lina in improving children’s sense of belonging within a classroom environment in Portugal, Czechia and the United Kingdom. Secondary objectives Secondary objectives of the study are: To test the impact of Lina on improving young people’s mental health and wellbeing (more broadly and, specifically, in terms of social anxiety and depression) To test the impact of Lina on other secondary outcomes including social awareness, loneliness and young people’s stigmatising beliefs. To collect the costs of delivering the intervention in comparison to routine school costs, and conduct a comprehensive economic evaluation to establish whether Lina presents good value for money. Further objectives Further objectives of the study are: To conduct an embedded implementation evaluation to investigate how Lina is delivered in secondary schools both within and outside of a trial setting. To understand adolescents' and teachers’ experience of participating in Lina and evaluate how the intervention can be adapted to meet the needs of adolescents who are particularly vulnerable to poor mental health. Methods: Patient and public involvement, and trial design Patient and public involvement {11} Young people were meaningfully involved as co-researchers during the development of the intervention, informing its content, format, and acceptability. Ongoing involvement of young people in the design of the trial itself is not planned. During trial dissemination, engagement will focus on participating teachers, communication liaisons and schools to play an active role in scale-up implementation and the promotion of key messages around the trial findings through dissemination activities. Trial design {12} The design of the study is a cluster randomised, parallel group controlled, school-based trial in three countries. Three separate trials will be conducted concurrently in Portugal (PT), Czechia (CZ) and the United Kingdom (UK). Overall, these three parallel trials will employ the same design, although there will be some differences to accommodate local contexts - where these differences are planned, they will be highlighted in the protocol. The intervention provided (i.e. Lina ) will replace usual lessons within the school term for a period of six lessons and will be facilitated by a teacher in CZ and the UK. In PT, these sessions will be delivered by a psychologist due to national regulatory stipulations on the type of professionals permitted to deliver mental health interventions to children in schools. Outcome data will be collected at baseline and immediately following intervention completion (8-10 weeks post-baseline), and at 6 months follow up. Trial data will be analysed separately in the first instance (i.e., country specific analysis) but will be later pooled to look for overall patterns in the data, particularly for the primary outcome (i.e., class belonging). Pooled data analysis will seek to determine if trial findings are replicated across different European national contexts, and to provide a larger, more varied sample for analysis of effectiveness. Methods: Participants, interventions and outcomes Trial setting {13} The trial will be conducted within middle schools in Portugal, elementary schools in Czechia and secondary schools in the UK, recruiting whole classes that are comprised of adolescents primarily aged 12-13 years. Lina has been developed for young people aged 11-14 years and selecting 12-13 years for the modal age in evaluation is a pragmatic decision, which avoids years following major school transitions in PT, CZ and the UK, when we would expect a trajectory of change in mental well-being over the course of the year (i.e., acclimatisation to a new school environment), which could confound the results of the trial. Schools will be identified through informal conversations, existing networks and local school events. The project team has been actively building relationships with schools since the start of the ASP belong programme (September 2023). There will be two types of school involved: i) flagship schools and, ii) trial schools. Flagship schools will work with the trial team to support networking, and wider engagement, particularly in mainstream media and educational networks. All interested schools will initially be defined as flagship schools. Those flagship schools who are keen to be part of the trial will be supported to become trial schools. Therefore, all trial sites will come from within this network of flagship schools. Schools that become trial schools will therefore already have knowledge of Lina through conversations with the research team, public-facing material such as YouTube videos, or presentations during research events and conferences. We will attempt to purposively recruit trial schools in all three countries, based on their geographical location and other factors of interest, such as level of deprivation. Schools will be invited to join the trial via formal recruitment documents. They will be sent a Local Information Pack which will include the protocol and organisation information document that will act as the data sharing agreement. Recruitment strategies will be tailored to each country’s national context. Characteristics of the people who are needed for the trial Characteristic The people we would expect to see included Age 13 years old in the UK 15 years old in Portugal 13 years old in Czech Republic Sex Male Female Non-binary Prefer not to say Gender Same as above. Race, ethnicity and ancestry United Kingdom: White (including English, Welsh, Scottish, Northern Irish, British; Irish; Gypsy or Irish Traveller; any other White background) Mixed/Multiple ethnic groups (including White and Black Caribbean; White and Black African; White and Asian; any other Mixed/Multiple ethnic background) Asian/Asian British (including Indian; Pakistani; Bangladeshi; Chinese; any other Asian background) Black/African/Caribbean/Black British (including African; Caribbean; any other Black/African/Caribbean background) Other ethnic group (including Arab; any other ethnic group) I prefer not to answer this question Czech Republic: Czech Ukrainian Russian Romani Vietnamese Slovak Other I prefer not to answer this question Portugal: Portuguese Brazilian Portuguese English Moldovan Ukrainian Nepali Chinese Other I prefer not to answer this question Socioeconomic status UK and Czechia: What is the highest level of education completed by at least one of your parents? Geographic location Birmingham, United Kingdom Brno, Czech Republic · Torres Vedras, Portugal In CZ and the UK, schools will be recruited near to the respective research bases (University of Birmingham and Masaryk University), which both reflect urban areas, with high numbers of relatively disadvantaged schools. Other characteristics relevant to the trial Proportion of students receiving 1:1 support by school staff (to determine level of special educational needs in the population) Proportion of students who have previously attended another school (to determine level of mobility of students between schools in the population) Eligibility criteria for participants {14a} Eligibility criteria for student participants will be consistent across the three trials, to ensure that the sample is comparable and trial data from the three trials can be pooled. Inclusion criteria Schools will be included as ‘trial schools’ if they: are a school in the UK with grade 8 students (aged 12-13) are a school in Portugal with grade 8 and 9 students (aged 12-15) are a school in Czech with grade 7 students (aged 12-13) agree to support the delivery of the Lina as part of routine school activities in the 2025/26 academic year agree to the process of randomisation, with the understanding that classes which are randomly allocated to the control group will have to wait until the 2026/27 school year to implement the Lina Individual young people will be included in the trial if: they are 12-13 years old in the UK they are 12-15 years old in Portugal they are 12-13 years old or are classes with 12-13 years old in Czech Republic they are part of a class with similarly aged students assent to the collection of self-reported questionnaire data at key timepoints through the trial (baseline, 8-10 weeks post baseline, and 6 months baseline) they have a parent / legal guardian who has provided written informed consent for collection of the young person's personal data (only in CZ) The variation across the age eligibility criteria in each trial country is reflective of the differences in the educational systems, grade structures and ethical requirements in the United Kingdom, Czech Republic and Portugal. In the UK, year 8 students are almost uniformly 12-13 years old, while in Czechia and Portugal there is a high rate of grade retention for students. While the modal age for the intervention is still 12-13 years, the higher number of older children in the corresponding grades in the trial is informed by a pragmatic approach that prioritises inclusion and ecological validity across the vulnerable population. From this trial sample, a subsample of young people will be invited to attend an interview or focus group as part of the study’s implementation evaluation and/ or exploration of lived experiences of Lina . The specific inclusion criteria and sampling methodology for this aspect of the study is outlined in Section 15. Exclusion criteria Young people will be excluded from the trial if: they have a parent or guardian who explicitly requests for them to be opted out of the trial Even if a young person, or a parent or guardian requests for the young person to be excluded from the study and they “opt out” of participation, the young person will still receive the Lina intervention as part of routine school activities. The “opt out” refers to the completion of the trial outcome measures only. Eligibility criteria for sites and those delivering interventions {14b} Schools will be included as ‘trial schools’ if they: are a school in the UK with grade 8 students (aged 12-13) are a school in Portugal with grade 8 and 9 students (aged 12-15) are a school in Czech with grade 7 students (aged 12-13) agree to support the delivery of the Lina as part of routine school activities in the 2025/26 academic year agree to the process of randomisation, with the understanding that classes which are randomly allocated to the control group will have to wait until the 2026/27 school year to implement the Lina Young people will be included if they: Are aged 12-13 years old in the UK Are aged 12-13 years old, or in a class among other students aged 12-13 years old in Czechia Are aged 12-15 years old in Portugal Who will take informed consent? {32a} Schools signing up to the trial will have already made the decision that the intervention does not differ significantly enough in terms of risk or content from standard school activities to indicate that any consent will be required from individual students in order for them to partake in the Lina experience. This is critical to the successful delivery of the intervention as Lina requires the inclusion of whole classes of young people. Thus, for the purpose of the trial, consent will specifically mean consent for completing trial measures and the contribution of trial data. Therefore, in PT and the UK an “opt-out” method of parental consent will be utilised. This means that schools, in collaboration with the trial team, will inform parents and students about the trial fully before any baseline measures are taken. The study team will work with schools to identify the best way to reach all relevant parents/carers with information about the trial, particularly about the types of data we will be collecting and the questions we will be asking as part of the standardised outcome measures. The trial team will also endeavour to organise information events at each school to give further information about the trial and outline what is involved so that adolescents and parents/carers are fully informed. For example, in many schools this will include researchers attending a parents meeting when we will talk to all attending parents about the study and signpost where parents/carers can find out more information about the research and be given the opportunity to ask any questions about the research, before enrolment in the study takes place. Therefore, all young people within a trial classroom will be enrolled in the trial unless an express request has been made by the student and/or their parent/ carer to not be involved. In such cases, young people will still take part in Lina as part of their usual school activities, but no trial outcome data will be collected from them, and they will not be included in the trial sample. Such “opt -out” consent has been used widely in school-based studies of this type (e.g. DEER study (14)) to improve recruitment, reduce researcher burden and improve engagement and information-giving with participants and parents/ carers. Trial schools can request that consent procedures are altered or changed based on parent feedback, and these decisions will be made on a school-by-school basis. In CZ, local research ethics requirements preclude the possibility of out-out consent. In this country, parents/ legal guardians will be asked to provide written consent for their children to participate, which must be in place prior to the commencement of data collection. In all 3 countries, young people will also complete a survey consent form at the point of baseline data collection, to document that the study has been explained to them, they’ve had the opportunity to ask questions and they adequately understand what information they are expected to give, and they assent to their provided data being used in this way. For students and teachers who are invited to participate in the qualitative interviews and focus groups that make up part of the implementation and/or lived experience evaluation, full informed consent will be collected before any data is collected. All participant information sheets and consent forms are provided in Appendix 1. Additional consent provisions for collection and use of participant data and biological specimens {32b} Not Applicable - The study is not collecting any biological specimens. All consent provisions have been mentioned under heading 32a . Intervention and comparator Intervention and comparator description {15a} Description of the intervention The intervention under investigation Lina is a newly developed software-led program with accompanied in-person reflection designed to enhance students' sense of belonging through a blended approach of interactive gameplay facilitated by smartphones in a classroom setting. All necessary equipment, including smartphones, routers, headphones, and paper-based materials will be provided by the trial team to the class. The intervention is primarily user-driven but will be guided by the classroom teacher (or a psychologist in the case of PT). Additionally, a researcher will be present during every session to make observational notes and support usage, where required. The intervention consists of six sessions . Four of these are “episodes” of the Lina story and will be delivered on a provided individual smartphone, whilst two will be “analogue” sessions, which are structured and interactive sessions within the classroom to enhance the sense of belonging and embed the psychotherapeutic principles inherent in the intervention. In CZ and the UK, it is typically teachers who will deliver the analogue sessions, in line with detailed lesson plans and provided materials. In PT the psychologist members of our team will deliver these sessions, in line with national legislation. The order will be as follows: Lesson 1: Lina episode 1 Lesson 2: Lina episode 2 Lesson 3: Analogue session 1 Lesson 4: Lina episode 3 Lesson 5: Lina episode 4 Lesson 5: Analogue session 2 During the smartphone-based sessions, each student plays a character in a fictional class. The four Lina episodes follow the story of a girl called Lina, a fictional classmate who abruptly left the school. Lina had been secretive, and at times, Lina’s behaviour seemed unusual or difficult to understand. The class collectively decides to uncover what happened to her. Players examine objects Lina left behind using augmented reality, revisit shared memories, and piece together the story. By the last episode, they learn that Lina has been caring for her mother, who struggles with a poor mental health (low mood, guilt) that has profoundly affected their daily lives. Lina and her mother have moved to live with Lina’s aunt, allowing her mother to receive support while Lina returns to her previous school. Gameplay emphasises collaboration and problem-solving, both individually and in varying group sizes. Students (and occasionally the teacher) work together to solve puzzles, exchange information, and help one another progress. Group compositions are intentionally mixed throughout the sessions to ensure every student interacts with their peers. Each Lina episode ends in a 5-minute out-of-character period of reflection, still led by the smartphone. Using Lina’s story, the teacher- or psychologist-led analogue sessions help students process the narrative and deepen their understanding of the themes explored (e.g., perspective taking, empathy, impact hidden challenges). The group will reflect on the overall experience, their classroom dynamics and their sense of belonging within the group. This will enable contextualisation of the main learning themes. All necessary materials for these reflection sessions will be supplied by the trial team. Description of the comparator Control classes will engage in standard school activities/routine lessons and will be provided the intervention in the beginning of the next school calendar year. Criteria for discontinuing or modifying allocated intervention/comparator {15b} As the trial allocates intervention at the classroom level, discontinuation or modification of the allocated interventions in the trial may occur at the following levels: Individual student-level: A student may postpone or terminate active participation in the intervention if a) excused by the teacher or school administration in accordance with the school’s policies or procedures or, b) severe safeguarding concerns related to the intervention as determined by the Trial Steering Committee (TSC) Class-level: An intervention class session may be postponed or terminated early due to a) operational constraints such as emergency closures, strikes or staff shortages experienced by the school or b) severe safeguarding concerns related to the intervention determined by the TSC Strategies to improve adherence to intervention/comparator {15c} We will develop Standard Operating Procedures (SOPs) around consenting procedures, data collection and management and intervention delivery to ensure fidelity and adherence to the protocol. All implementation researchers will fill out session logs to introduce a standard monitoring framework for data quality. Although we don't have any target tools to measure adherence and fidelity specifically, we will be monitoring fidelity and adherence to the intervention recording the number and content of each session using observation forms which will be filled out by researchers facilitating Lina lessons. Concomitant care permitted or prohibited during the trial {15d} As this is taking place within routine classes in schools, students and teachers will continue to receive all usual educational and wellbeing support delivered by schools. Given the vulnerable status of young participants in the trial, they will not be excluded from accessing additional interventions during the trial period. Information on the use of any additional support services availed of by students as a result of the trial within schools will be captured through trial assessments (e.g. Health Economics Inventory forms) and reviewed in the analysis to assess the cost of delivering the intervention in the schools. Ancillary and post-trial care {34} This trial has been identified as a low-risk, school-based psychosocial intervention so we do not anticipate participants would require ancillary or post-trial care. In the event that participants do require additional support, they will continue to have access to the usual educational and mental health support available within their schools and we will follow school safeguarding policies and procedures at all times. The study is covered under the University of Birmingham's standard research indemnity scheme for participants. Outcomes {16} The trials will collect information from participants on a range of mental health, social and economic evaluation related outcomes including sense of belonging, symptoms of depression, social anxiety, loneliness, quality of life, stigma, social awareness and resource use. Primary outcome The primary outcome will be sense of belonging/ class climate as measured by the Delaware School Climate Survey- Student (DSCS-S) measured post intervention (8-10 weeks) and at follow-up. This is a 23-item student-report scale to measure the sense of belonging an individual feels within a classroom context (15). The scale is comprised of five subscales: Teacher-Student Relationships; Student-Student Relationships; School Safety; Fairness of the Rules and School Liking (16). Items are rated on a Likert scale, with negatively worded items reverse-scored. Subscale scores for Teacher–Student Relationships, Student–Student Relationships, School Safety, Fairness of the Rules, and School Liking are computed as the mean of their respective items. An overall school climate score is calculated as the mean of all 23 items. The DSCS-S is justified for measuring this outcome as it demonstrates strong psychometric validity and reliability in Portugal (17), Anglophone contexts e.g. United States (16), and in Eastern European settings e.g. Serbia (18) along with widespread international use in low resource settings. The wording of the items, in all three languages, has been adapted slightly to ask about the class climate, as opposed to the overall school climate. This is in order to make the measure sensitive to the climate of the specific classroom in which the intervention was delivered. Secondary outcomes In line with the developing Lina theory of change, secondary outcomes were selected to assess constructs anticipated to be affected by Lina. General wellbeing may be increased via increased belonging or other aspects associated with Lina such as exposure to the arts. Social anxiety and depression were selected as symptoms of mental distress that are both some of the most commonly experienced in adolescents, and (in the case of social anxiety) most likely to be positively impacted by Lina . Social awareness represents an area of psychological resources expected to be positively impacted by Lina. Loneliness is sometimes conceptualised as the counterpoint to belonging and is expected to be positively impacted by the positive class environment created by Lina. Finally, the Lina story touches directly on mental health issues in a way designed to reduce stigma. Measure selection was strongly influenced by availability of prior validation with young people in PT (where specific regulatory constraints exist around measures that can be used with young people in school settings), and by availability of data on sensitivity to change. Thus, the following student-report measures were selected. For all questionnaires, the total score (sum of all items) is the unit of analysis. WHO-5 Well-being Index is a 5-item measure of general well-being that has proven reliability and criterion validity amongst adolescents in the United Kingdom, Portugal and Czech Republic as part of a large cross-national validation study (19). Scores are transformed to a score from 0 to 100, with lower scores indicating worse well-being (20). Patient Health Questionnaire-8 is an 8-item screening tool designed to assess the presence of depression symptoms (21). PHQ-8 has strong equivalence with PHQ-9, has been tested for reliability and validity in 27 European countries - including the United Kingdom, Portugal and Czech Republic (22) and has demonstrated high internal consistency when administered with adolescents from vulnerable settings (23). The total score can range from 0–24, with a score of ≥10 indicative of clinical-level depression (21). Social Anxiety Scale for Adolescents (SAS-A) is an 18-item questionnaire measuring adolescents’ social anxiety experiences in the context of peer relations (24). SAS-A has proven reliability and validity for Portuguese adolescents (25) and has been used in school-based screening of adolescents across France and Spain (26–28) with acceptable internal consistencies and validity. It contains three subscales: Fear of Negative Evaluation, Social Avoidance and Distress-New and Social Avoidance and Distress-General. Total score ranges from 0-90 with a higher score indicating a higher level of social anxiety (24). The 4-item University of California Los Angeles (UCLA) Loneliness Scale is a revised and shorter version of the full UCLA tool (20 items) (29). The full UCLA scale demonstrated modest internal consistency in the assessment of loneliness in children and adolescents (30). This version of the UCLA has been recommended by the Office of National Statistics in the United Kingdom (30,31) as a strong measure of loneliness in youth aged 10-15 years, following adaptations. The tool has been translated and validated in Portugal and Slovakia with a modest internal consistency (32,33). Social-Emotional Learning Edition of the Strengths and Difficulties Inventory System [brief version] (SSIS SELb) Social Awareness subscale is a 4-item assessment that evaluates the social-emotional skills of children and adolescents in relation to their social awareness. It measures how much students take into account others’ point of view, particularly those from different backgrounds (34). SSIS SELb was translated and validated for use among school-going adolescents in 6 European countries including Portugal with a strong measurement for reliability and structural validity, supporting its use for international research with appropriate adaptation and translation (34). Peer Mental Health Stigmatisation Scale-Revised (PMHSS-R) Stigma Awareness subscale is 5-item assessment of individually held stigmatising beliefs. It is answered on a 5-point Likert scale of agreement (35). PMHSS-R has been developed in Ireland (35) and validated in European contexts (Spain) (36) but there is no country-specific validation for the United Kingdom, Portugal and Czech Republic. However, at the time of drafting this protocol, PMHSS-R is currently the only validated tool that assesses both awareness and agreement of stigma and was considered justified in use for measuring these outcomes in the trial. EQ-5D-Y-3L is a child-friendly questionnaire to describe young peoples’ health across five dimensions: Mobility; Looking After Myself; Doing Usual Activities; Having Pain or Discomfort; and Feeling Worried, Sad or Unhappy (37). Each dimension has three levels of response. The tool has been translated in Czech (38) and Portuguese (39) and demonstrates strong psychometric evidence for validity and reliability with adolescents in the United Kingdom (40) and among Portuguese speakers (39). Child Health Utility-9D (CHU-9D) is a self-report measure of health-related quality of life suitable for 7- to 17-year-olds. It consists of 9 dimensions each measuring a different domain (worried, sad, pain, tired, annoyed, schoolwork, sleep, daily routine and activities). Each domain has 5 levels of severity. The CHU-9D has been locally translated for administration among young people in Portugal, Czech Republic (41) and the United Kingdom and demonstrated modest internal consistency and validity among children, adolescents and young adults within the UK and Portuguese speakers (39). Resource use data We will collect three groups of data for resource use in the economic evaluation. First, we will collect data from teachers/psychologists on their time spent preparing and delivering Lina and usual sessions. The data will be collected for three periods, i.e. at baseline (with 3 months recall), the end of 8-10 weeks intervention (with 8-10 weeks recall for control group and weekly data collection for intervention group after each Lina session), and 6 months follow up (with 6 months recall). In addition to time spent by teachers/psychologists, we will also collect data on other professionals’ time spent (e.g. administrative staff, teaching assistants) on delivering Lina or usual sessions. We developed four Health Economics Inventory forms for data collection on time spent by teachers/psychologists and other professionals. Second, our research team will collect data on the quantity and costs of equipment used for delivering Lina sessions, including smartphones, routers, headphones, and paper-based materials. Third, we will collect data on time spent by teachers/psychologists and other professionals (e.g. administrative staff, teaching assistants, counsellors) providing additional mental health/wellbeing support to students as well as managing students’ disruptive behaviours. The data will be extracted from school records for the period from 3 months before baseline till the end of 6 months follow up. Qualitative data Following completion of Lina , focus groups and interviews will be conducted with both student participants and teachers who were involved to collect implementation and experiential data. Focus groups and interviews will be audio recorded and anonymised transcripts will be the data subject to analysis. For the purpose of data analysis, transcripts for 3 interviews, 1 focus group with young people, and 1 teacher focus group from each country will be translated initially and the UK, CZ, and PT teams will collaboratively devise a coding framework. This framework will then be used to conduct first-level data analysis separately in each country. Data will then be collated and analysed together by UK, CZ, and PT researchers collaboratively. Implementation evaluation data To further understand how Lina would be implemented as part of routine school activities, and to inform dissemination and further implementation strategies, an embedded implementation evaluation will be conducted both during the trial and after it is completed. The implementation evaluation will draw from multiple data sources, using a mixed methods design, to get a full insight into the barriers and facilitators that would affect Lina delivery and learn how to increase reach and improve roll out. This evaluation will be conducted across trial schools in all three countries. The primary data sources will be: Questionnaire measures completed by teachers - Teachers from intervention classes will complete questionnaires on feasibility (“Feasibility of Intervention Measure”), acceptability (“Acceptability of Intervention Measure”), and appropriateness (“Appropriateness of Intervention Measure”) (42) after each episode/session of Lina to give feedback on each session. They will then also complete these measures at post-intervention timepoint to feedback on the intervention as a whole. Implementation data provided by teachers - Teachers from intervention classes will answer three broad questions on Lina “what went well?”, “what didn’t go well?”, and “what could have gone better?”. These questions will be asked by the researcher after each session of Lina for immediate feedback on the delivery of that session. Teachers will also answer these questions, retrospectively, at the end of the intervention to give feedback on Lina as a whole. Structured observations - A researcher will be present to conduct structured observations of all Lina sessions. Focus groups (teachers and psychologists) - Following the completion of Lina, teachers will be invited to participate in focus groups to elaborate on their experience of implementation , and give interactive feedback on potential strategies to facilitate implementation. Focus groups (young people) - Students from intervention classes who experienced Lina will be invited to participate in focus groups where they can elaborate on their lived experience of using the intervention and how its delivery could be improved. Data Collection Timepoints The baseline measures will be completed after the class has been randomised, but prior to the beginning of the intervention. Baseline measures will be collected at least one week before the first session of Lina . It is most likely that baseline data will be collected two weeks before the first Lina session, therefore allowing enough time to collect data from all students in the class. Post-intervention measures will be collected between 8 and 10 weeks from the date of baseline assessments (allowing a 2 week time window, whilst accounting for the instances where classes hold multiple intervention sessions in a week). Six month follow up measures will be collected within four weeks (either side) of the date of six whole months since baseline assessments. Measures will be completed as part of the routine school day, within a class session. If a participant is absent from school, or data is missing for any reason, then the research team will have 3 weeks from the data collection time point to collect that data. All trial assessments will need to take place within the 2025/26 academic year. In the rare case that schools or classes are delayed in their delivery of Lina and final follow up falls outside of the summer academic term then follow-ups may need to take place sooner than 6 months post baseline. Harms {17} Participation involves low expected risk e.g. emotional distress during data collection, safeguarding disclosures during the intervention, or minor physical injury during classroom activities. Risks will be mitigated through the use of age-appropriate measures, clear information about voluntary participation and withdrawal and clear Standard Operating Protocols to guide researchers on how to identify and manage risks sensitively when working with adolescents, and delivery in schools with existing safeguarding support. Researchers will monitor participants throughout all activities and may pause or stop data collection if concerns arise. Clear procedures are in place to guide measured responses to any harm identified or reported and escalate concerns to school safeguarding leads where required. All adverse events are recorded (expected, unexpected, related or unrelated), with serious events reported promptly to the research leadership and ethics committees within 24 hours. Participant timeline {18} TRIAL PERIOD Enrollment Post-randomization TIMEPOINT b -t i to 0 t 0 (Baseline) t 1 (Post- intervention) t 2 (6-months) ENROLLMENT: X Eligibility screen X Allocation/Randomisation X Informed consent X INTERVENTION/ COMPARATOR: Lina lessons X -----------------> X Routine school lessons X -----------------> X ASSESSMENTS (YOUNG PEOPLE): Demographics X Delaware School Climate Survey- Student X X X WHO-5 Well-being Index X X X Patient Health Questionnaire-8 X X X Social Anxiety Scale for Adolescents (SAS-A) X X X University of California Los Angeles (UCLA) Loneliness Scale X X X Social-Emotional Learning Edition of the Strengths and Difficulties Inventory System [brief version] (SSIS SELb) X X X Peer Mental Health Stigmatisation Scale-Revised (PMHSS-R) X X X Health-related Quality of Life EQ-5D-Y-3L X X X Child Health Utility-9D (CHU-9D) X X X Intervention ( Lina ) feedback X Interviews and Focus Groups X ASSESSMENTS (TEACHERS): Demographics X Health Economics Resource Inventory X X X Implementation evaluation form (Feasibility, Acceptability, Appropriateness) X Intervention ( Lina ) feedback X Focus Groups X Sample size {19} Size of trial sample Based on an assumed small to medium effect size (Cohen’s d = 0.4), a conservative Intraclass Correlation Coefficient (ICC) of 0.1, which takes into account the clustering at the class and school level, and a design effect of 2.7, 40 classes per country will provide 90% power (alpha = 0.05). The analysable trial sample assumes an average cluster size of 18, (a total of 720 participants per country). To allow for an anticipated drop-out rate of 20%, an average cluster size of 22 will be recruited at baseline (i.e., average 22 adolescents per classroom), thus giving a total sample size of 880 per country. The cluster size of 22 at baseline takes into account the variability in class sizes within and across each country, and expected number of participants who opt out of the study. Size of interview and focus group sample For the post-trial interviews and focus groups it is predicted that there will be a maximum of 160 young people per country invited to participate in the evaluative qualitative work (up to 120 young people invited to a focus group, and 40 young people invited to be interviewed). For teachers, there is predicted to be 20 teachers per country eligible to be interviewed or invited to a focus group. Recruitment {20} Sampling technique In order to recruit 40 classes per country, we predict that around 10 schools per country will need to be recruited, with each contributing an average of 4 class cohorts. We anticipate there will be variations in the number of class cohorts available within individual schools across countries. This will represent an overall opportunistic sampling method, making use of schools who have indicated an interest in the Lina and have agreed to become a flagship school. However, we will aim to purposively recruit schools with higher levels of deprivation as deprivation is linked to greater risk of poor mental health. In PT, the percentage of Free and Reduced Cost School Meals will be used as an indicator of deprivation. Young people who come from the lowest economic socioeconomic status have free lunches (they are listed as A in the school support system) and young people from low, but slightly higher, socioeconomic status families pay 50% of the lunch (and they are listed as B in the school support system). We will aim to recruit schools with the highest numbers of students listed in category A for Free and Reduced School Meals. In CZ and the UK, schools will be recruited near to the respective research bases (University of Birmingham and Masaryk University), which both reflect urban areas, with high numbers of relatively disadvantaged schools. Although priority will be given to pragmatic considerations (ease of access, eagerness of school to participate), local knowledge will be used to preferentially shift recruitment towards more disadvantaged schools. In the UK, this is reflected by schools having a higher-than-average proportion of students meeting the low socioeconomic status criterion for additional school funding from the government (“pupil premium”), as available on government websites (≈>30%). In both countries it is reflected by relatively high levels of ethnic minority students, as ascertained based on local knowledge. Recruitment of schools Schools will be identified, approached and recruited across the three countries using a number of different strategies that are adapted to the national context. In general, the trial team will make use of existing networks, conferences, seminars and learning events attended by headteachers and teachers to promote the study, and assess interest. Those schools that want to support the study will be offered to become a “flagship school” to support in the networking within educational networks about the intervention and the objectives of the trial. Flagship schools will be given the opportunity to become a trial school (i.e. a trial site from which we recruit classes and participants from), but this will not be mandatory. Sample identification Once a school has agreed to be a trial school then the trial team will support them to identify whole classes that have students that meet the eligibility criteria. We will work with schools to assess how best to deliver Lina within the routine school day, i.e. identify a specific subject or class that could integrate the intervention and be part of the regular school day. As an example, in the UK it is likely that the intervention will be delivered as part of Personal, Social, Health and Economic (PSHE) lessons which covers a range of topics related to personal development. However, schools can individually choose where they think Lina best fits within their curriculum. The variation of subjects and lesson content both across schools and across countries means that the trial team will take a pragmatic approach to delivery and support the schools in making tailored decisions. It is recommended to schools that each of the six Lina sessions are delivered weekly for six weeks within a single term. However, due to the pragmatic nature of the trial, and the understanding that schools (both within and between countries) structure lessons in different ways, schools may choose to deliver the sessions at different frequencies or across shorter or longer time periods (e.g., some schools may choose to deliver two sessions of Lina a week for three weeks). The variation in delivery will be collected as the observational data and form part of the analysis. Irrespective of the intervention delivery, follow up outcome measures will be collected at 8-10 weeks after baseline. Interview and focus group sampling Purposive sampling will be used to identify individuals of interest to participate in the planned post-trial interviews and focus groups (that make up part of the implementation evaluation and exploration of lived experiences). For young people, individual interview data will be collected from particularly vulnerable students, who want to talk about Lina (i.e. have something to say), and have characteristics that make them more likely to have relatively extreme (good or bad) experiences of Lina . Focus group data will be collected from students who want to talk about Lina , for example because they have had a particularly good or bad experience of Lina. In the UK the vulnerable students for interviews will be defined by three separate criteria: i) recipient of pupil premium ii) having special educational needs and disabilities (SEND) and iii) having experienced ‘notable social experiences’ e.g. negative experiences like bullying and/or positive social experiences such as being part of an extracurricular club or society outside of school. Students will have the opportunity to self-identify with (any of) these characteristics and teachers will also be asked to recommend students. In PT and CZ, students for interviews will be identified based on discussion with teachers. In all countries, students will be given the opportunity to self-select for focus group participation, and students may also be recommended by teachers or by observing researchers. For teachers- all teachers who facilitated the use of Lina will be invited to attend an interview or focus group. Assignment of interventions: randomisation Sequence generation: who will generate the sequence {21a} Randomisation scheme The trial will employ a cluster randomised design, with class being the unit of randomisation. Whole classes will be randomised to either the Lina arm or the control group arm. The trial statistician at Queen Mary University of London will use STATA to randomise a list of classroom IDs to either intervention or control conditions. IDs will then be assigned to classes in the order in which they are enrolled. Classes within schools will be randomised at the same time (where possible) and the school and individual teachers will be informed of their allocation by the local research assistant or the trial manager. Sequence generation: type of randomisation {21b} Randomisation will be stratified by country, and then stratified by blocks of 2 or 4. The randomisation scheme may be amended as and when the full list of participating trial schools is known. Any future amendment to the randomisation scheme will be there to ensure that there is at least one class in the Lina arm per school (important for school retention) and to ensure that there are comparable numbers of participants randomised to each of the trial arms. Randomisation will occur only when: schools have agreed to be part of the trial; appropriate classes that meet the inclusion criteria have been identified; adolescents have agreed to the study and all students have been allocated to the class. Once these terms have been met then randomisation can be triggered. Randomisation will occur before participant baseline data collection. The allocation ratio will be 1:1. Allocation concealment mechanism {22} Due to the nature of the trial, allocation concealment can only be maintained at the level of data collection. To ensure allocation concealment, password-protected randomisation allocation lists generated by the statistician will be maintained in Excel files and shared only with the Trial Manager and unblinded researchers in each trial team responsible for intervention scheduling. Passwords for the excel sheets will be communicated via a secure separate channel and deleted afterwards to prevent accidental disclosure to blinded researchers responsible for facilitating trial assessments. Logs containing any data linking classroom-level information to concealment will be restricted to unblinded researchers until the end of the trial assessments (e.g. post-intervention and 6-month follow-up) Implementation {23} As the unit of randomisation in this trial is the classroom, all students within participating classrooms will be enrolled into the trial, provided they have met the relevant consent criteria. The procedure is listed below: The trial team in each country will be responsible for enrolling eligible classrooms within recruited schools. A list of classroom IDs will be produced and shared with the Trial Statistician who will generate the allocation sequence using block randomisation (blocks of two and four) to assign classrooms to intervention or control arms. IDs will then be assigned to classes in the order in which they are enrolled. Assignment of interventions: blinding Who will be blinded {24a} Blinding Due to the nature of the intervention under investigation and the cluster design of the trial, blinding participants (and teachers) to their allocation will not be possible. Baseline data will be collected post-randomisation, but prior to the start of the intervention. Participants in the class will not be informed of allocation prior to baseline data collection, (although teachers will be aware due to pragmatic considerations around lesson planning, for example). In the UK trial, researchers facilitating the baseline, post-intervention and 6-months follow up will be blinded to allocation where possible. Due to researcher capacity in Portugal and Czechia, blinding will not be possible at any of the post-intervention follow ups (i.e., T1 and T2). The statistician and health economists conducting the analysis will be unblinded at the time of analysis but corresponding analysis plans will be finalised and signed off before commencement of analysis. How will be blinding be achieved {24b} Blinded researchers will be determined prior to the start through the Trial Delegation log. To avoid any unblinding, efforts will be made to ensure that unblinded researchers are not responsible for coordination, allocation information will be stored separately from assessment material, will be password-protected and masked in any analysis datasets until the primary analysis is completed. Procedure for unblinding if needed {24c} Unblinding researchers to participant allocation may occur in the interest of participant safety e.g. if the knowledge of the participant’s allocation is necessary for the appropriate management of an adverse event or severe adverse event. Any such request would be formally documented in a trial file note, and reported to the Principal Investigator and Trial Manager. Data collection and management Plans for assessment and collection of outcomes {25a} All outcome measures used have been validated for use with adolescents. The list of outcome measures was decided upon thorough consultation with the Trial Management Group (TMG) and a panel of young co-researchers (see heading 12 for full list of outcome measures). Data Collection for Outcome Measures Electronic case report forms (e-CRF) will be created to collect socio-demographic data and outcome data (separate versions for each timepoint) (these can be accessed on the ASP belong Open Science Framework project page (43)). The e-CRFs will be hosted on smartphone-compatible software that will link to the online trial database (REDCap) through a unique participant number. At baseline, a record will be created in the database for each participant. Following baseline data collection, an individual URL will be created by the REDCap software for each participants’ data row. At post Lina and follow up data collection timepoints, a bespoke application (built by the project team) will open the e-CRF linked to the correct URL when the corresponding participant number is entered. Participants will complete the measures on the smartphones provided by the study team (the same devices used to deliver the intervention). In the event of technical challenges with electronic data entry (e.g. Wi-Fi issues), paper forms will be used to complete the assessment. e-CRFs will be completed as part of the routine school day, within a class session. They will be collected from all consenting students within that class at the same time, facilitated by the class teacher or a psychologist (PT) and a researcher (UK, CZ), who will offer support where needed around understanding questions in a consistent manner within each country context (i.e. explaining certain terminology within item wording that students query). If a participant is absent from school, or data is missing for any reason, then the research team will have 3 weeks from the data collection time point to collect that data. Plans to promote participant retention and complete follow-up {25b} We will not be collecting any individual-level contact information for participants except where necessary to coordinate data collection for people actively opting into interviews and/or focus groups. Efforts for participant retention and mitigating attrition will therefore be on a school-level. We have worked on establishing strong relationships with schools and teachers through regular communication, several networking opportunities, and emphasising a strong sense of collaboration. Further, we will be flexible with scheduling lessons to accommodate the academic calendar/exam time, or any other school events. No data will be collected from students who withdraw themselves or whose parents withdraw them from the trial. Furthermore, in the event that a student was to leave the school or be transferred to a different class within the same school during the intervention, they would cease to receive the intervention, and no further data would be collected from them. Data management {26} The primary mode of data capture will be through electronic Case Report Forms (e-CRFs) administered on smartphones via REDCap (Research Electronic Data Capture) which is a secure, web-based system designed for building and managing research data. If REDCap is unavailable (e.g. device malfunction, connectivity issues), paper Case Report Forms (CRFs) will be used. Paper CRFs will be entered into REDCap at the earliest opportunity, with the paper copy stored securely at each site in a locked cabinet and stored separately from any identifiable enrolment information. Each participant survey will be linked to a unique participant ID (PID), and the follow-up assessments are linked to it. Paper-based data can be transferred between individual sites (e.g. schools) to the central site but will never leave the central site (e.g. University of Birmingham in UK, Masaryk University in CZ and Académico Torres Vedras (ATV) in Portugal). Access to the REDCap portal will be granted to designated and trained researchers at each site for the manual data entry of paper CRFs into the online portal. Site leads and researchers will be responsible for first-level quality control of the data entry and checks. The trial manager will oversee routine monitoring and any data errors in the database will be queried and resolved with the relevant site team. Once data is entered into REDCap, data exports can be produced through reports for data verification and analysis by the Trial Statistician. Confidentiality {33} The trial will comply with the requirements of the UK Data Protection Act 2018, as standard, with regards to the collection, storage, processing and disclosure of personal information and will uphold the Act’s core principles throughout the study, and be UK General Data Protection Regulation (GDPR) compliant. As all trial data (from all three countries) will be stored in the UK, the relevant national legislation of the UK will be followed: All data will be confidential at the point of collection, linked to participants via unique ID numbers. Identifying information (participant full names and contact details) will only be collected for participants (students and teachers) in the qualitative and implementation evaluations, and only when necessary (e.g. to arrange data collection with a student, which may otherwise be arranged via the class teacher). Personal information will be stored in password protected spreadsheets at the local research site (University of Birmingham, Masaryk University, Académico Torres Vedras) and linked to research data via the unique ID. Interviews and focus groups (qualitative and implementation evaluations) will be audio recorded and these data will be potentially identifying. Recordings will be stored securely at each research site until transcription, when any potentially identifying information will be removed (transcripts will be anonymous). Following verification of the transcripts, the audio data will be deleted. Only anonymous data will be shared across research sites for analysis. Statistical methods Statistical methods for primary and secondary outcomes {27a} Statistical Analysis Data for the three trials will be analysed separately (by country), before later being pooled for overall analysis. Participant level socio-demographic data and cluster level (classroom) data will be summarised at baseline for both arms of the trial. The primary outcome is the Delaware Class Climate score at the end of Lina delivery (8-10 weeks post baseline and follow-up). This will be compared between Lina and control groups using a linear mixed effects model with a random effect for classroom and school, allowing for the clustering of children, within classes, and within schools. The model will include baseline level of the Delaware Class Climate as a covariate, as well as demographics (that are known to affect outcome). The analysis will use intention to treat by including all participants in the arm to which they were randomised, whether or not they completed the Lina programme and including all students in the analysis by using multiple imputation. We will set out in the Statistical Analysis Plan (SAP) how missing data will be handled, including planned sensitivity analyses. Secondary outcomes are WHO-5, PHQ-8, SAS-A, UCLA Loneliness Scale, SSIS SELb, PMHSS-R, EQ-5D-Y-3L and CHU-9D all measured at post-intervention (T1) and 6 months post baseline (T2). Each variable will be analysed using a generalised linear mixed effects model with a link function appropriate to the outcome distribution, with random effects for classroom and school. All models will include the baseline value of the outcome. A full statistical analysis plan (SAP) will be developed prior to exporting data from the database and reviewed by the trial steering committee. Data analysis will not be conducted prior to final sign off of the SAP. The SAP will be made publicly available prior to data lock. Once country level data has been analysed, then data from across the three countries will be pooled and analysed as one dataset. This will follow analysis as described above but with further level of clustering at the country level. The full analysis plan for the pooled analysis will also be described in the SAP. Economic Evaluation We will conduct an economic evaluation alongside the three trials aiming to assess the cost effectiveness of Lina in comparison with usual lessons from a school perspective. The time horizon for the evaluation will be from the point of randomization until the 6-months follow-up. Intention-to-treat analysis will be applied. The primary outcome for our economic evaluation is the Quality Adjusted Life Years (QALYs), to be converted from the CHU-9D data by applying for the UK tariff (44). Secondary outcomes include the EQ-5D-Y-3L and the Delaware Class Climate score. The outcomes data will be collected at baseline, post-intervention, and 6 months follow up using the e-CRFs. Resource use includes three groups, i.e. (1) time spent by teachers/psychologists on preparing and delivering Lina and usual sessions as well as other professionals’ time spent on delivering Lina and usual sessions, (2) resource use for providing necessary equipment to deliver Lina sessions and (3) time spent by teachers/psychologists and other professionals on providing additional support to students as well as managing students’ disruptive behaviours. We will collect relevant unit cost data to convert the quantity of resource use for each item to monetary values. The cost for resource use will be presented at student and time point level (i.e. baseline, immediately after intervention, and 6-months follow-up). We will explore the appropriate approach to handle missing values in costs and outcome data. No discounting will be required for costs and outcomes data. A cost utility analysis will be performed on each country’s data to estimate the incremental costs of Lina compared to usual lessons per additional QALY gained (or the Incremental Cost-Effectiveness Ratio (ICER)). We will report the uncertainties around the point estimate of the ICER. Also, the point estimate will be compared against the country specific willingness-to-pay threshold(s). We will pool data from the three countries together to conduct a multiple-country cost utility analysis. A few sensitivity analyses will be performed including (1) using the EQ-5D-Y-3L and the Delaware Class Climate score as outcome measures (2) conducting economic evaluation under alternative scenarios related to implementation (e.g. frequency of session delivery) to help contextualise the findings for future implementation (3) applying for alternative approach(es) to handle missing values. A Health Economic Analysis Plan will be signed off before the start of the economic evaluation. Who will be included in each analysis {27b} All randomised clusters (i.e. classroom) and their enrolled participants will be included in the primary analyses according to the intention-to-treat (ITT) principle, whereby participants will be analysed in the group to which their classroom was originally allocated (i.e. control or intervention). How missing data will be handled in the analysis {27c} Analysis will follow the intention-to-treat principle, meaning all participants will be analysed in the groups to which their classes were assigned, regardless of protocol deviations where contamination may have occurred. Any protocol deviation will be reported to the Trial Manager and formally documented. The proportion of missing data from each instrument in the trial assessments (i.e. student and teacher CRFs) will be summarised across assessment timepoints and their reasons will be described and discussed keeping in mind contextual realities within each trial site. Missing data will be handled by multiple imputation by chained equations using the MI package in STATA and efforts will be made to ensure that imputed values stay within the valid range of each questionnaire. Results from the imputed dataset will then be combined using Rubin’s rules to produce final estimates that account for uncertainty due to missing data. Methods for additional analyses (e.g. subgroup analyses) {27d} Additional and subgroup analyses will be fully detailed in the Statistical Analysis plan, including sensitivity analyses to examine the impact of missing data imputation. Subgroup analyses will explore differential treatment effects across genders and across high (top quartile) versus not high (lower three quartiles) baseline levels of social anxiety (SAS-A). The effect of adherence on sense of belonging (DCCS) will be examined via comparison of participants who received “sufficient” Lina to those that did not receive Lina or did not complete “sufficient” Lina. “ Sufficient” Lina is defined as at least 4 Lina sessions, including the last 2 and either the first or second (based on the content of each session in the context of current knowledge on mechanisms of change). Interim analyses {28b} No interim analysis will be conducted. A trial steering committee composed of relevant cross-disciplinary professionals from the Czech Republic, Portugal and the UK (4 members), will have the power to terminate the trial based on regular reports on implementation, including adverse events. Protocol and statistical analysis plan {5} This study protocol will be made publicly accessible through publication in a peer-reviewed journal as well as the ISRCTN record (https://www.isrctn.com/ISRCTN11613092). The trial Statistical Analysis Plan (SAP) will be finalised before the database lock and published on University of Birmingham’s OSF record as well as to the study protocol as an update at a later stage. Oversight and monitoring Composition of the coordinating centre and trial steering committee {3d} The trial manager is based at Queen Mary University of London, where trial statistics and health economist teams are also based. These researchers will not play a direct role in data collection, but will form part of the Trial Management Group (TMG). The TMG will additionally comprise leads of the teams carrying out Lina implementation in each country, and at least one representative from each team actually carrying out implementation on the ground. The two design leads of Lina will also be part of the TMG. The TMG will meet weekly for the duration of the trial. The trial steering committee (TSC) is independent of the TMG. It includes key professions relevant to the trial and its members are distributed among the 3 participating countries. A trialist and statistician is based in the UK and will independently review the SAP. An education practitioner with additional experience in research is based in the Czech Republic. A psychologist with experience in youth mental health is based in Portugal. Finally, a youth worker from the UK will represent both lay and youth voices. The TSC will meet once before the trial commences and from then on, at 3–6-month intervals until data collection and analysis are complete. The committee will receive monthly reports on ongoing implementation, including any adverse events and will have the responsibility to call exceptional meetings should any concerns arise. Following their activity, they will produce a final report summarising their work and any lessons learned. Composition of the data monitoring committee, its role and reporting structure {28a} We do not have a separate Data Monitoring Committee, but the Trial Steering Committee will also act as the Data Monitoring and Ethics Committee (DMEC) and will be responsible for the review of the safety reports, e.g., number of serious adverse events. Frequency and plans for auditing trial conduct {29} Oversight will be maintained through regular (weekly) virtual check-ins and in-person site visits to the trial sites in the United Kingdom, Portugal and Czech Republic conducted by the Trial Manager (from Queen Mary University London) to ensure adherence to the protocol, data quality, trial procedures and documentation. Protocol amendments {31} Any important protocol modifications (e.g. changes to eligibility criteria, outcomes, analysis plans, or trial procedures) will be communicated to and discussed with the Trial Management Group (includes the Chief Investigator, site lead, trial lead and manager, site researchers, statistician and health economist) and the Trial Steering Committee (TSC). Amendments will be updated in the trial registry (ISRCTN), and shared with trial researchers. All approved amendments will be documented with version control. Dissemination policy {8} Trial findings will be disseminated following the ASP belong programme’s dissemination and communication plan, which is reviewed and revised regularly and comprises a deliverable of the project, publicly available via the European Commission. The plan includes a commitment to fully open access publications. Discussion This trial has been designed to evaluate the effectiveness of Lina, a novel, game-based digital intervention intended to improve classroom-level belonging among children ages 12-13 across three European countries. As a cluster Randomised Controlled Trial with a pragmatic approach, the study design and procedures have been intentionally aligned within routine educational systems and structures to improve recruitment rates and operational feasibility. In selecting the unit of randomisation, we weighed up the increased risk of contamination, which would come with class as the unit of randomisation, with the expectation that our recruitment and retention would be greatly facilitated by ensuring that all involved schools had some classes engaged with the intervention throughout. Particularly given the non-explicit nature of the Lina intervention, which aims to improve class climate and belonging by the specific experiences of collaboration acquired by experiencing Lina together, we judged the risk of contamination to be relatively small compared to that of the expected recruitment and retention challenges that would have come from using school as a unit of randomisation. Despite the intention for trial to be as similar as possible across the three countries, local contexts have required substantial specific considerations. Some of these have been integrated into the overall design, and others have led to country-specific procedures. For example, the core requirement for prior local validation of any student-facing questionnaires used in Portugal was one of the primary criteria we considered in selection of our outcome measures, and doing this has allowed us to maintain consistency in effectiveness outcome measures across countries. However, the legal requirement in Portugal for any intervention in the realm of psychological wellbeing (i.e. that could be badged as psychotherapeutic) to be administered by psychologists has required a different plan for implementation in Portugal relative to the other sites. When judging where to make country-specific modifications and where to push for consistency, we considered the long-term picture of likely implementation “in the wild”. Thus, where country-specific context suggested that a particular scenario would likely be relevant to long-term use of Lina in that setting (e.g. the Portuguese example of needing psychologists to implement the programme), we were more inclined to make those country-specific modifications to trial design. Blinding was an issue which we regularly and widely debated within our TMG. Given the nature of the intervention, neither students, teachers or observing researchers can be blind to the intervention versus control group allocation. However, we had originally intended that researchers collecting data would be blind to the allocation. During the detailed process of laying down scheduling and teams in each implementation site however, it quickly became apparent how challenging it would be to keep any team members blind to allocation. We are aiming to achieve this where possible, but it is highly dependent on the practical set-up of each implementing team. And in the eventuality of any illness or other unexpected events within the teams, it is likely that at least some of the blinding will be jeopardised. We also considered maintaining the statistician conducting the analysis blind to allocation. However, in the context of the additional pragmatic challenges (resource demands) that would entail, we deemed that the prior full specification of the statistical analysis plan would appropriately minimise that risk of bias. As the first evaluation of any Augmented Social Play intervention post early stage piloting of a Lina , proof-of-concept, these trials will be definitive in terms of assessing the strength and scope of the benefits that may be mediated by ASP. Although ASP, including Lina, represents an entirely novel combination of active elements, each of these (e.g. fictional story, collaborative puzzle solving, mobile-device mediated, evidence-based psychotherapeutic techniques) is well known within its primary disciplinary field. Results of these trials therefore have the potential to stimulate exciting new transdisciplinary work towards securing youth mental health and wellbeing, within a specific ASP context and beyond. Trial status Protocol version number: v1.0 Protocol Date: 12 January 2026 Date recruitment started: 22 September 2025 Approximate date recruitment will be complete: 16 January 2026 Abbreviations AE Adverse events ASP Augmented Social Play CRFs Case report forms CZ Czechia DMEC Data Monitoring and Ethics Committee eCRFs Electronic case report forms GDPR General Data Protection Regulation ICER Incremental cost-effectiveness ratio ICC Intraclass correlation coefficient PID Participant ID PSHE Personal, Social, Health and Economic education PT Portugal QALYs Quality-adjusted life years REC Research Ethics Committee SAE Serious adverse Event SEND Special educational needs and disabilities SAP Statistical analysis plan TMF Trial Master File TMG Trial Management Group TSC Trial Steering Committee UK United Kingdom Declarations Acknowledgements We would like to thank the group of 10 young people aged 14-16 years known to our ASPbelong consortium as “adolescent coresearchers” for reviewing trial measures. Staff and young people at All Saints Youth Project in Birmingham supported interview schedule development. Raynes Park High School in London supported a mock trial of the Lina trial in which a number of aspects of data collection were piloted. Thanks also to RMG Associates for facilitating this relationship. We would like to acknowledge the contribution of all researchers and students who supported the review of trial design and data collection procedures across participating sites and academic partners; University of Birmingham (interns - Max Bawden, Jessica Large, and Monica Patel; and research assistants), Académico Torres Vedras (Ana Sofia Rodrigues, Ana Maria Romão, Ana Rita Ferreira, Catarina Chaves, Sofia Saldanha and Vanda Sousa), Masaryk University (Aleš Přibík, Diana Turčeková, Martina Střechová, Barbora Prikrylová, Kristína Tomanková) and Queen Mary University of London (Sarah Bourdin). Authors’ contributions {3a} K.W. is the Chief Investigator; she conceived the study, led the proposal and protocol development. T.M. contributed to protocol development and writing, led implementation in the United Kingdom, and led the implementation evaluation. O.Q. is the trial manager and contributed to protocol development and writing along with P.M. and V.B. who is the trial oversight lead. A.B., G.M., V.B., V.C., and A.S. contributed to study design and to development of the proposal. A.F. led implementation in the United Kingdom, and the qualitative evaluation. V.C., P.B., and M.M. led implementation in Portugal. A.S., A.P., T.H., and C.S. led implementation in Czechia. B.S. is the trial statistician and developed the statistical analysis plan. Y.F. is the health economist and led the economic evaluation. N.M. supported implementation in the United Kingdom and led project management. All authors read and approved the final manuscript. Sources of funding and other support {7a} Funding and support in kind: Funder(s) Names and contact details of organisations providing funding and/or support in kind for this trial Financial and non-financial support given EU Horizon Europe Provided funding for the ASP-Belong programme, including the cluster RCT UK Research & Innovation Provided funding for the ASP-Belong programme, including for the cluster RCT University of Birmingham Study sponsorship and substantive employer of Chief Investigator Queen Mary University of London Substantive employer of Work Package lead, statistician, health economist and trial manager ATV - Académico de Torres Vedras Substantive employer of Portuguese implementers and support researchers Masaryk University Substantive employer of Czech implementers and support researchers Trial schools Permissions to conduct the trial on school premises with school staff and students. Some support costs and resources provided. Availability of data and materials {6} Data will be made open access by the time of publication of corresponding results at the latest. Ethics approval and consent to participate {30} The University of Birmingham Science and Technology Ethics Committee has given a favourable ethical opinion for the three trials. Relatedly the University of Birmingham is also acting as the sole sponsor. Local approvals have been sought from institutional ethics committees (IECs) in Portugal and Czechia: Académico Torres Vedras and Masaryk University, respectively. Details of all ethical approvals are as follows: UK - Approved 06/05/2025 Science, Technology, Engineering and Mathematics Committee University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom +44 (0)121 414 3344 [email protected] ) Ref: ERN_3004-May2025 PT - Approved 08/09/2025 Comissão de Ética e Deontologia da Faculdade de Psicologia Faculdade de Psicologia, Alameda da Universidade, Lisboa, 1649-013, Portugal +351 217 943 655 [email protected] Ref: N/A CZ - Approved 18/09/2025 Etická Komise pro výzkum Masarykovy Univerzity Research Ethics Committee at Masaryk University, Masarykova Univerzita, Žerotínovo nám. 617/9, Brno 602 00, Česká republika, Brno, 602 00, Czech Republic +420 549 49 6290 [email protected] Ref: EKV-2022-090 Consent for publication Not applicable. No identifiable individual participant data will be published. Competing interests {7b} The authors declare that they have no competing interests. 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21:23:23","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8595707/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8595707/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106725424,"identity":"2d457b77-0238-46f4-976a-e7fab1f065e0","added_by":"auto","created_at":"2026-04-12 18:32:50","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2766743,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8595707/v1/5bc9edf5-adc4-49e3-a7e5-bca48bdd13d3.pdf"},{"id":106597897,"identity":"5a67d6b7-e2db-4642-add9-ef2ea63cbbd6","added_by":"auto","created_at":"2026-04-10 09:47:45","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":34918,"visible":true,"origin":"","legend":"","description":"","filename":"SPIRIT2025ChecklistLinaStudyProtocol.docx","url":"https://assets-eu.researchsquare.com/files/rs-8595707/v1/d375781b9302708efe68fa96.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Three cluster randomised controlled trials in Portugal, Czechia and the United Kingdom to test the effectiveness and cost-effectiveness of an augmented social play intervention in schools to support real- world connection and sense of belonging (Lina trial protocol)","fulltext":[{"header":"Structured summary","content":"\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eItem\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eDescription\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003ePrimary Registry and Trial Identifying Number {4}\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003eISRCTN (Identifier: ISRCTN11613092, registered on 15 September 2025.\u003cbr\u003e\u0026nbsp;https://doi.org/10.1186/ISRCTN11613092\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eSecondary Identifying Numbers\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003eNot Applicable\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eSource(s) of Monetary or Material Support\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003eHorizon Europe (101080665) and UK Research and Innovation\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003ePrimary Sponsor and contact information {3b}\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003eUniversity of Birmingham\u003c/p\u003e\n \u003cp\u003eScience, Technology, Engineering and Mathematics Committee\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eUniversity of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom\u003c/p\u003e\n \u003cp\u003e+44 (0)121 414 3344\u003c/p\u003e\n \u003cp\[email protected]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eRole of sponsor and funder {3c}\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003eNone\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eContact for Public Queries\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\[email protected]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eContact for Scientific Queries\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003eProf. Kate Anne Woodcock\u003c/p\u003e\n \u003cp\u003eProfessor of Applied Clinical Psychology\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eUniversity of Birmingham, School of Psychology\u003c/p\u003e\n \u003cp\u003e52 Pritchatts Road, Edgbaston, Birmingham, B15 2SA\u003c/p\u003e\n \u003cp\u003eTel: +44 (0)121 414 6036\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003ePublic Title\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003eEvaluating social connection and belonging in schools: Protocol for three randomised controlled trials of \u003cem\u003eLina\u003c/em\u003e, a digital intervention in Portugal, Czechia and the United Kingdom\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eScientific title\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003eThree cluster randomised controlled trials in Portugal, Czechia and the United Kingdom to test the effectiveness and cost-effectiveness of an augmented social play intervention in schools to support real-world connection and sense of belonging (\u003cem\u003eLina\u003c/em\u003e trial protocol)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eCountries of Recruitment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003eUnited Kingdom, Czech Republic (Czechia), Portugal\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eHealth Condition(s) or Problem(s) Studied\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003eSense of belonging\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eIntervention(s)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003eA classroom-based group intervention utilising a augmented social play application (\u003cem\u003eLina\u003c/em\u003e) to enhance a sense of belonging, connectedness and mental health literacy among young people\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eKey Inclusion and Exclusion Criteria\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003eInclusion criteria:\u003c/p\u003e\n \u003cul\u003e\n \u003cli\u003eA registered school in the UK, Portugal and Czechia enrolling students in grades 7-9\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eStudents aged 12-13 in UK and Czechia and 12-15 years in Portugal\u003c/li\u003e\n \u003c/ul\u003e\n \u003cp\u003eExclusion criteria:\u003c/p\u003e\n \u003cul\u003e\n \u003cli\u003eYoung people whose parent or guardian explicitly requests for them to be opted out of the trial\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eStudy Type\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003eThree cluster randomised, parallel group-controlled trial in schools across Portugal, Czechia and United Kingdom,\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eDate of First Enrollment (planned)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003e22/09/2025\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eSample Size\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003eA total of 880 young people to be recruited per country, assuming an average cluster size of 22 per class (with a drop-out rate of 20%), 40 classes per country, thus giving a total sample size of 880 per country.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003ePrimary outcome(s)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003eSense of belonging/class climate measured by Delaware School Climate Survey- Student (DSCS-S) at baseline, post-intervention (8-10 weeks) and at follow-up (6 months)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eKey Secondary outcome(s)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cul\u003e\n \u003cli\u003eGeneral wellbeing index, measured by WHO-5\u0026nbsp;at baseline, post-intervention (8-10 weeks) and at follow-up (6 months)\u003c/li\u003e\n \u003cli\u003eDepression symptom severity, measured by Patient Health Questionnaire-8 at at baseline, post-intervention (8-10 weeks) and at follow-up (6 months)\u003c/li\u003e\n \u003cli\u003eLevel of social anxiety, measured by Social Anxiety Scale for Adolescents (SAS-A)\u0026nbsp;at baseline, post-intervention (8-10 weeks) and at follow-up (6 months)\u003c/li\u003e\n \u003cli\u003eLevel of loneliness, measured by the UCLA Loneliness Scale for Children at baseline, post-intervention (8-10 weeks) and at follow-up (6 months)\u003c/li\u003e\n \u003cli\u003eLevel of social awareness measured by the Social Emotional Learning Scale-brief version \u0026ndash; SSIS SELb (social awareness subscale)\u0026nbsp;at baseline, post-intervention (8-10 weeks) and at follow-up (6 months)\u003c/li\u003e\n \u003cli\u003eLevel of mental health stigma measured by the Peer Mental Health Stigmatisation Scale Revised - PMHSS-R (stigma awareness subscale)\u0026nbsp;at baseline, post-intervention (8-10 weeks) and at follow-up (6 months)\u003c/li\u003e\n \u003cli\u003eYouth quality of life measured by the EQ-5D-Y-3L at baseline, post-intervention (8-10 weeks) and at follow-up (6 months)\u003c/li\u003e\n \u003cli\u003eQuality-adjusted life years for adolescents measured by the Child Health Utility - CHU-9D\u0026nbsp;at baseline, post-intervention (8-10 weeks) and at follow-up (6 months)\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eEthics Review\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003col\u003e\n \u003cli\u003e\u003cstrong\u003eUK - Approved 06/05/2025\u003c/strong\u003e\u003c/li\u003e\n \u003c/ol\u003e\n \u003cp\u003eScience, Technology, Engineering and Mathematics Committee\u003c/p\u003e\n \u003cp\u003eUniversity of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom\u003c/p\u003e\n \u003cp\u003e+44 (0)121 414 3344\u003c/p\u003e\n \u003cp\[email protected])\u003c/p\u003e\n \u003cp\u003eRef: ERN_3004-May2025\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003col start=\"2\"\u003e\n \u003cli\u003e\u003cstrong\u003ePT - Approved 08/09/2025\u003c/strong\u003e\u003c/li\u003e\n \u003c/ol\u003e\n \u003cp\u003eComiss\u0026atilde;o de \u0026Eacute;tica e Deontologia da Faculdade de Psicologia\u003c/p\u003e\n \u003cp\u003eFaculdade de Psicologia, Alameda da Universidade, Lisboa, 1649-013, Portugal\u003c/p\u003e\n \u003cp\u003e+351 217 943 655\u003c/p\u003e\n \u003cp\[email protected]\u003c/p\u003e\n \u003cp\u003eRef: N/A\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003col start=\"3\"\u003e\n \u003cli\u003e\u003cstrong\u003eCZ - Approved 18/09/2025\u003c/strong\u003e\u003c/li\u003e\n \u003c/ol\u003e\n \u003cp\u003eEtick\u0026aacute; Komise pro v\u0026yacute;zkum Masarykovy Univerzity\u003c/p\u003e\n \u003cp\u003eResearch Ethics Committee at Masaryk University, Masarykova Univerzita, Žerot\u0026iacute;novo n\u0026aacute;m. 617/9, Brno 602 00, Česk\u0026aacute; republika, Brno, 602 00, Czech Republic\u003c/p\u003e\n \u003cp\u003e+420 549 49 6290\u003c/p\u003e\n \u003cp\[email protected]\u003c/p\u003e\n \u003cp\u003eRef: EKV-2022-090\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eIndividual Trial Participant Data sharing statement\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003eDe-identified datasets will be available after publication of the primary trial results in alignment with the ethics guidelines for approval in each country.\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"Introduction","content":"\u003cp\u003e\u003cstrong\u003eBackground and rationale {9a}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePoor mental health and social isolation are increasing among young people (1). Belonging \u0026ndash; feeling connected to and accepted by others through supportive interpersonal relationships has been shown to be an important factor in improving mental health and overcoming loneliness in adolescent populations (2,3). A greater sense of school belonging has been associated with a wide array of personal and social benefits including increased psychological wellbeing \u003cw:sdt docpart=\"2D0960EEA5BB40C1B7B86455B7492C60\" sdttag=\"MENDELEY_CITATION_v3_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\" id=\"1527603166\"\u003e(4)\u003c/w:sdt\u003e and reduced instances of school violence, truancy, mental illness, and bullying (5\u0026ndash;7).\u003c/p\u003e\n\n\u003cp\u003eThere is, however, a lack of evidence-based interventions addressing belonging, particularly in schools, where socialisation plays a distinct and key role (8). Evidence-based school interventions could therefore be implemented to promote belonging, making use of an opportunistic target and potentially improving outcomes for adolescents (9).\u003c/p\u003e\n\n\u003cp\u003eDigital technologies offer enormous potential for adolescent health promotion and management (10,11). The ASP-Belong programme of research has developed \u003cem\u003eLina, \u003c/em\u003ea novel intervention whose feasibility has been established through a proof-of-concept prototype (12,13). \u003cem\u003eLina \u003c/em\u003euses smartphones to deliver an in-person group experience, in a classroom, that combines immersive storytelling, augmented reality, collaborative gameplay and evidence-based psychotherapeutic techniques to strengthen sense of belonging within the classroom .\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eLina\u003c/em\u003e is the first full-scale version of a new intervention format - Augmented Social Play - which shares the same key ingredients but can be abstracted to different in-person group settings. \u003cem\u003eLina \u003c/em\u003eis a multi-session intervention that is delivered within the context of routine school lessons.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eRationale\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWhilst feasibility has been evidenced through previous work, the effectiveness of the intervention is yet to be established. The current trial is therefore the next step in developing \u003cem\u003eLina \u003c/em\u003eand demonstrating its effectiveness on a variety of wellbeing and mental health outcomes, but primarily on sense of belonging. The trial and embedded implementation evaluation will give definitive answers as to how effective this novel intervention is across three national contexts. It will also produce understanding about the best ways to implement the intervention into routine school activities across a number of different contexts, and about young people\u0026apos;s lived experiences of \u003cem\u003eL\u003c/em\u003e\u003cem\u003eina\u003c/em\u003e, with a particular focus on those who face additional vulnerabilities to poor mental health.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eExplanation for the choice of comparator {9b}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere is no established, widespread school intervention to enhance sense of belonging. Therefore, control classes will continue with standard school activities (i.e., treatment as usual). This comparison offers the most relevant basis for informing educational and policy decisions.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eObjectives {10}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResearch aim\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe primary aim of the trials is to assess the effectiveness of \u003cem\u003eLina\u003c/em\u003e in improving children\u0026rsquo;s sense of belonging within a classroom environment in Portugal, Czechia and the United Kingdom.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSecondary objectives\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSecondary objectives of the study are:\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003eTo test the impact of \u003cem\u003eLina \u003c/em\u003eon improving young people\u0026rsquo;s mental health and wellbeing (more broadly and, specifically, in terms of social anxiety and depression)\u003c/li\u003e\n\u003cli\u003eTo test the impact of \u003cem\u003eLina \u003c/em\u003eon other secondary outcomes including social awareness, loneliness and young people\u0026rsquo;s stigmatising beliefs.\u003c/li\u003e\n\u003cli\u003eTo collect the costs of delivering the intervention in comparison to routine school costs, and conduct a comprehensive economic evaluation to establish whether \u003cem\u003eLina \u003c/em\u003epresents good value for money.\u003cbr\u003e \u003cbr\u003e \u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eFurther objectives\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFurther objectives of the study are:\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003eTo conduct an embedded implementation evaluation to investigate how \u003cem\u003eLina \u003c/em\u003eis delivered in secondary schools both within and outside of a trial setting. \u003c/li\u003e\n\u003cli\u003eTo understand adolescents\u0026apos; and teachers\u0026rsquo; experience of participating in \u003cem\u003eLina \u003c/em\u003eand evaluate how the intervention can be adapted to meet the needs of adolescents who are particularly vulnerable to poor mental health.\u003c/li\u003e\n\u003c/ul\u003e"},{"header":"Methods: Patient and public involvement, and trial design","content":"\u003cp\u003e\u003cstrong\u003ePatient and public involvement {11}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eYoung people were meaningfully involved as co-researchers during the development of the intervention, informing its content, format, and acceptability. Ongoing involvement of young people in the design of the trial itself is not planned. During trial dissemination, engagement will focus on participating teachers, communication liaisons and schools to play an active role in scale-up implementation and the promotion of key messages around the trial findings through dissemination activities.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eTrial design {12}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe design of the study is a cluster randomised, parallel group controlled, school-based trial in three countries. Three separate trials will be conducted concurrently in Portugal (PT), Czechia (CZ) and the United Kingdom (UK). Overall, these three parallel trials will employ the same design, although there will be some differences to accommodate local contexts - where these differences are planned, they will be highlighted in the protocol. \u003c/p\u003e\n\n\u003cp\u003eThe intervention provided (i.e. \u003cem\u003eLina\u003c/em\u003e) will replace usual lessons within the school term for a period of six lessons and will be facilitated by a teacher in CZ and the UK. In PT, these sessions will be delivered by a psychologist due to national regulatory stipulations on the type of professionals permitted to deliver mental health interventions to children in schools. Outcome data will be collected at baseline and immediately following intervention completion (8-10 weeks post-baseline), and at 6 months follow up.\u003c/p\u003e\n\u003cp\u003eTrial data will be analysed separately in the first instance (i.e., country specific analysis) but will be later pooled to look for overall patterns in the data, particularly for the primary outcome (i.e., class belonging). Pooled data analysis will seek to determine if trial findings are replicated across different European national contexts, and to provide a larger, more varied sample for analysis of effectiveness. \u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eMethods: Participants, interventions and outcomes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTrial setting {13}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe trial will be conducted within middle schools in Portugal, elementary schools in Czechia and secondary schools in the UK, recruiting whole classes that are comprised of adolescents primarily aged 12-13 years. \u003cem\u003eLina\u003c/em\u003e has been developed for young people aged 11-14 years and selecting 12-13 years for the modal age in evaluation is a pragmatic decision, which avoids years following major school transitions in PT, CZ and the UK, when we would expect a trajectory of change in mental well-being over the course of the year (i.e., acclimatisation to a new school environment), which could confound the results of the trial. \u003c/p\u003e\n\n\u003cp\u003eSchools will be identified through informal conversations, existing networks and local school events. The project team has been actively building relationships with schools since the start of the ASP\u003cem\u003ebelong\u003c/em\u003e programme (September 2023). There will be two types of school involved: i) flagship schools and, ii) trial schools. Flagship schools will work with the trial team to support networking, and wider engagement, particularly in mainstream media and educational networks. All interested schools will initially be defined as flagship schools. Those flagship schools who are keen to be part of the trial will be supported to become trial schools. Therefore, all trial sites will come from within this network of flagship schools. Schools that become trial schools will therefore already have knowledge of \u003cem\u003eLina\u003c/em\u003e through conversations with the research team, public-facing material such as YouTube videos, or presentations during research events and conferences.\u003c/p\u003e\n\n\u003cp\u003eWe will attempt to purposively recruit trial schools in all three countries, based on their geographical location and other factors of interest, such as level of deprivation. Schools will be invited to join the trial via formal recruitment documents. They will be sent a Local Information Pack which will include the protocol and organisation information document that will act as the data sharing agreement. Recruitment strategies will be tailored to each country\u0026rsquo;s national context. \u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCharacteristics of the people who are needed for the trial\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCharacteristic\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eThe people we would expect to see included\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eAge\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e \u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cul\u003e\n\u003cli\u003e13 years old in the UK\u003c/li\u003e\n\u003cli\u003e15 years old in Portugal\u003c/li\u003e\n\u003cli\u003e13 years old in Czech Republic\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eSex\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e \u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cul\u003e\n\u003cli\u003eMale\u003c/li\u003e\n\u003cli\u003eFemale\u003c/li\u003e\n\u003cli\u003eNon-binary\u003c/li\u003e\n\u003cli\u003ePrefer not to say\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eGender\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003eSame as above.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eRace, ethnicity and ancestry\u003c/p\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eUnited Kingdom:\u003c/strong\u003e\u003c/p\u003e\n \u003cul\u003e\n\u003cli\u003eWhite (including English, Welsh, Scottish, Northern Irish, British; Irish; Gypsy or Irish Traveller; any other White background)\u003c/li\u003e\n\u003cli\u003eMixed/Multiple ethnic groups (including White and Black Caribbean; White and Black African; White and Asian; any other Mixed/Multiple ethnic background)\u003c/li\u003e\n\u003cli\u003eAsian/Asian British (including Indian; Pakistani; Bangladeshi; Chinese; any other Asian background)\u003c/li\u003e\n\u003cli\u003eBlack/African/Caribbean/Black British (including African; Caribbean; any other Black/African/Caribbean background)\u003c/li\u003e\n\u003cli\u003eOther ethnic group (including Arab; any other ethnic group)\u003c/li\u003e\n\u003cli\u003eI prefer not to answer this question\u003c/li\u003e\n \u003c/ul\u003e\n \n \u003cp\u003e\u003cstrong\u003eCzech Republic:\u003c/strong\u003e\u003c/p\u003e\n \u003cul\u003e\n\u003cli\u003eCzech\u003c/li\u003e\n\u003cli\u003eUkrainian\u003c/li\u003e\n\u003cli\u003eRussian\u003c/li\u003e\n\u003cli\u003eRomani\u003c/li\u003e\n\u003cli\u003eVietnamese\u003c/li\u003e\n\u003cli\u003eSlovak\u003c/li\u003e\n\u003cli\u003eOther\u003c/li\u003e\n\u003cli\u003eI prefer not to answer this question\u003c/li\u003e\n \u003c/ul\u003e\n \n \u003cp\u003e\u003cstrong\u003ePortugal:\u003c/strong\u003e\u003c/p\u003e\n \u003cul\u003e\n\u003cli\u003ePortuguese\u003c/li\u003e\n\u003cli\u003eBrazilian Portuguese\u003c/li\u003e\n\u003cli\u003eEnglish\u003c/li\u003e\n\u003cli\u003eMoldovan\u003c/li\u003e\n\u003cli\u003eUkrainian\u003c/li\u003e\n\u003cli\u003eNepali\u003c/li\u003e\n\u003cli\u003eChinese\u003c/li\u003e\n\u003cli\u003eOther\u003c/li\u003e\n\u003cli\u003eI prefer not to answer this question\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eSocioeconomic status\u003c/p\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eUK and Czechia:\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003eWhat is the highest level of education completed by at least one of your parents?\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eGeographic location\u003c/p\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cul\u003e\n\u003cli\u003eBirmingham, United Kingdom\u003c/li\u003e\n\u003cli\u003eBrno, Czech Republic\u003c/li\u003e\n\u003cli\u003e\u0026middot; Torres Vedras, Portugal\u003c/li\u003e\n \u003c/ul\u003e\n \u003cp\u003e\u003c/p\u003e\n \u003cp\u003eIn CZ and the UK, schools will be recruited near to the respective research bases (University of Birmingham and Masaryk University), which both reflect urban areas, with high numbers of relatively disadvantaged schools.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 283px;\"\u003e\n \u003cp\u003eOther characteristics relevant to the trial\u003c/p\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 358px;\"\u003e\n \u003cul\u003e\n\u003cli\u003eProportion of students receiving 1:1 support by school staff (to determine level of special educational needs in the population)\u003c/li\u003e\n\u003cli\u003eProportion of students who have previously attended another school (to determine level of mobility of students between schools in the population)\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\n\n\u003cp\u003e\u003cstrong\u003eEligibility criteria for participants {14a}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEligibility criteria for student participants will be consistent across the three trials, to ensure that the sample is comparable and trial data from the three trials can be pooled. \u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eInclusion criteria \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSchools will be included as \u0026lsquo;trial schools\u0026rsquo; if they:\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003eare a school in the UK with grade 8 students (aged 12-13)\u003c/li\u003e\n\u003cli\u003eare a school in Portugal with grade 8 and 9 students (aged 12-15) \u003c/li\u003e\n\u003cli\u003eare a school in Czech with grade 7 students (aged 12-13) \u003c/li\u003e\n\u003cli\u003eagree to support the delivery of the \u003cem\u003eLina\u003c/em\u003e as part of routine school activities in the 2025/26 academic year \u003c/li\u003e\n\u003cli\u003eagree to the process of randomisation, with the understanding that classes which are randomly allocated to the control group will have to wait until the 2026/27 school year to implement the \u003cem\u003eLina\u003c/em\u003e\u003c/li\u003e\n\u003c/ul\u003e\n\n\u003cp\u003eIndividual young people will be included in the trial if:\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003ethey are 12-13 years old in the UK\u003c/li\u003e\n\u003cli\u003ethey are 12-15 years old in Portugal\u003c/li\u003e\n\u003cli\u003ethey are 12-13 years old or are classes with 12-13 years old in Czech Republic\u003c/li\u003e\n\u003cli\u003ethey are part of a class with similarly aged students\u003c/li\u003e\n\u003cli\u003eassent to the collection of self-reported questionnaire data at key timepoints through the trial (baseline, 8-10 weeks post baseline, and 6 months baseline)\u003c/li\u003e\n\u003cli\u003ethey have a parent / legal guardian who has provided written informed consent for collection of the young person\u0026apos;s personal data (only in CZ)\u003c/li\u003e\n\u003c/ul\u003e\n\n\u003cp\u003eThe variation across the age eligibility criteria in each trial country is reflective of the differences in the educational systems, grade structures and ethical requirements in the United Kingdom, Czech Republic and Portugal. In the UK, year 8 students are almost uniformly 12-13 years old, while in Czechia and Portugal there is a high rate of grade retention for students. While the modal age for the intervention is still 12-13 years, the higher number of older children in the corresponding grades in the trial is informed by a pragmatic approach that prioritises inclusion and ecological validity across the vulnerable population. \u003c/p\u003e\n\n\u003cp\u003eFrom this trial sample, a subsample of young people will be invited to attend an interview or focus group as part of the study\u0026rsquo;s implementation evaluation and/ or exploration of lived experiences of \u003cem\u003eLina\u003c/em\u003e. The specific inclusion criteria and sampling methodology for this aspect of the study is outlined in Section 15.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eExclusion criteria \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eYoung people will be excluded from the trial if:\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003ethey have a parent or guardian who explicitly requests for them to be opted out of the trial\u003c/li\u003e\n\u003c/ul\u003e\n\n\u003cp\u003eEven if a young person, or a parent or guardian requests for the young person to be excluded from the study and they \u0026ldquo;opt out\u0026rdquo; of participation, the young person will still receive the \u003cem\u003eLina \u003c/em\u003eintervention as part of routine school activities. The \u0026ldquo;opt out\u0026rdquo; refers to the completion of the trial outcome measures only.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eEligibility criteria for sites and those delivering interventions {14b}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSchools will be included as \u0026lsquo;trial schools\u0026rsquo; if they:\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003eare a school in the UK with grade 8 students (aged 12-13)\u003c/li\u003e\n\u003cli\u003eare a school in Portugal with grade 8 and 9 students (aged 12-15) \u003c/li\u003e\n\u003cli\u003eare a school in Czech with grade 7 students (aged 12-13) \u003c/li\u003e\n\u003cli\u003eagree to support the delivery of the \u003cem\u003eLina\u003c/em\u003e as part of routine school activities in the 2025/26 academic year \u003c/li\u003e\n\u003cli\u003eagree to the process of randomisation, with the understanding that classes which are randomly allocated to the control group will have to wait until the 2026/27 school year to implement the \u003cem\u003eLina\u003c/em\u003e\u003c/li\u003e\n\u003c/ul\u003e\n\n\u003cp\u003eYoung people will be included if they:\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003eAre aged 12-13 years old in the UK \u003c/li\u003e\n\u003cli\u003eAre aged 12-13 years old, or in a class among other students aged 12-13 years old in Czechia\u003c/li\u003e\n\u003cli\u003eAre aged 12-15 years old in Portugal\u003c/li\u003e\n\u003c/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWho will take informed consent? {32a}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSchools signing up to the trial will have already made the decision that the intervention does not differ significantly enough in terms of risk or content from standard school activities to indicate that any consent will be required from individual students in order for them to partake in the \u003cem\u003eLina\u003c/em\u003e experience. This is critical to the successful delivery of the intervention as \u003cem\u003eLina\u003c/em\u003e requires the inclusion of whole classes of young people. \u003c/p\u003e\n\u003cp\u003eThus, for the purpose of the trial, consent will specifically mean consent for completing trial measures and the contribution of trial data.\u003c/p\u003e\n\n\u003cp\u003eTherefore, in PT and the UK an \u0026ldquo;opt-out\u0026rdquo; method of parental consent will be utilised. This means that schools, in collaboration with the trial team, will inform parents and students about the trial fully before any baseline measures are taken. The study team will work with schools to identify the best way to reach all relevant parents/carers with information about the trial, particularly about the types of data we will be collecting and the questions we will be asking as part of the standardised outcome measures. The trial team will also endeavour to organise information events at each school to give further information about the trial and outline what is involved so that adolescents and parents/carers are fully informed. For example, in many schools this will include researchers attending a parents meeting when we will talk to all attending parents about the study and signpost where parents/carers can find out more information about the research and be given the opportunity to ask any questions about the research, before enrolment in the study takes place.\u003c/p\u003e\n\n\u003cp\u003eTherefore, all young people within a trial classroom will be enrolled in the trial unless an express request has been made by the student and/or their parent/ carer to not be involved. In such cases, young people will still take part in \u003cem\u003eLina\u003c/em\u003e as part of their usual school activities, but no trial outcome data will be collected from them, and they will not be included in the trial sample. Such \u0026ldquo;opt -out\u0026rdquo; consent has been used widely in school-based studies of this type (e.g. DEER study (14)) to improve recruitment, reduce researcher burden and improve engagement and information-giving with participants and parents/ carers.\u003c/p\u003e\n\u003cp\u003eTrial schools can request that consent procedures are altered or changed based on parent feedback, and these decisions will be made on a school-by-school basis.\u003c/p\u003e\n\n\u003cp\u003eIn CZ, local research ethics requirements preclude the possibility of out-out consent. In this country, parents/ legal guardians will be asked to provide written consent for their children to participate, which must be in place prior to the commencement of data collection.\u003c/p\u003e\n\n\u003cp\u003eIn all 3 countries, young people will also complete a survey consent form at the point of baseline data collection, to document that the study has been explained to them, they\u0026rsquo;ve had the opportunity to ask questions and they adequately understand what information they are expected to give, and they assent to their provided data being used in this way. \u003c/p\u003e\n\n\u003cp\u003eFor students and teachers who are invited to participate in the qualitative interviews and focus groups that make up part of the implementation and/or lived experience evaluation, full informed consent will be collected before any data is collected.\u003c/p\u003e\n\n\u003cp\u003eAll participant information sheets and consent forms are provided in Appendix 1.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAdditional consent provisions for collection and use of participant data and biological specimens {32b}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot Applicable - The study is not collecting any biological specimens. All consent provisions have been mentioned under heading \u003cem\u003e32a\u003c/em\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eIntervention and comparator\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eIntervention and comparator description {15a}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDescription of the intervention \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe intervention under investigation \u003cem\u003eLina\u003c/em\u003e is a newly developed software-led program with accompanied in-person reflection designed to enhance students\u0026apos; sense of belonging through a blended approach of interactive gameplay facilitated by smartphones in a classroom setting. All necessary equipment, including smartphones, routers, headphones, and paper-based materials will be provided by the trial team to the class.\u003c/p\u003e\n\n\u003cp\u003eThe intervention is primarily user-driven but will be guided by the classroom teacher (or a psychologist in the case of PT). Additionally, a researcher will be present during every session to make observational notes and support usage, where required. The intervention consists of six sessions . Four of these are \u0026ldquo;episodes\u0026rdquo; of the \u003cem\u003eLina\u003c/em\u003e story and will be delivered on a provided individual smartphone, whilst two will be \u0026ldquo;analogue\u0026rdquo; sessions, which are structured and interactive sessions within the classroom to enhance the sense of belonging and embed the psychotherapeutic principles inherent in the intervention. In CZ and the UK, it is typically teachers who will deliver the analogue sessions, in line with detailed lesson plans and provided materials. In PT the psychologist members of our team will deliver these sessions, in line with national legislation.\u003c/p\u003e\n\n\u003cp\u003eThe order will be as follows:\u003c/p\u003e\n\u003cp\u003eLesson 1: \u003cem\u003eLina \u003c/em\u003eepisode 1\u003c/p\u003e\n\u003cp\u003eLesson 2: \u003cem\u003eLina \u003c/em\u003eepisode 2 \u003c/p\u003e\n\u003cp\u003eLesson 3: Analogue session 1\u003c/p\u003e\n\u003cp\u003eLesson 4: \u003cem\u003eLina \u003c/em\u003eepisode 3\u003c/p\u003e\n\u003cp\u003eLesson 5: \u003cem\u003eLina \u003c/em\u003eepisode 4 \u003c/p\u003e\n\u003cp\u003eLesson 5: Analogue session 2 \u003c/p\u003e\n\n\u003cp\u003eDuring the smartphone-based sessions, each student plays a character in a fictional class. The four \u003cem\u003eLina\u003c/em\u003e episodes follow the story of a girl called Lina, a fictional classmate who abruptly left the school. Lina had been secretive, and at times, Lina\u0026rsquo;s behaviour seemed unusual or difficult to understand. The class collectively decides to uncover what happened to her. Players examine objects Lina left behind using augmented reality, revisit shared memories, and piece together the story. By the last episode, they learn that Lina has been caring for her mother, who struggles with a poor mental health (low mood, guilt) that has profoundly affected their daily lives. Lina and her mother have moved to live with Lina\u0026rsquo;s aunt, allowing her mother to receive support while Lina returns to her previous school.\u003c/p\u003e\n\n\u003cp\u003eGameplay emphasises collaboration and problem-solving, both individually and in varying group sizes. Students (and occasionally the teacher) work together to solve puzzles, exchange information, and help one another progress. Group compositions are intentionally mixed throughout the sessions to ensure every student interacts with their peers. Each \u003cem\u003eLina \u003c/em\u003eepisode ends in a 5-minute out-of-character period of reflection, still led by the smartphone.\u003c/p\u003e\n\n\u003cp\u003eUsing Lina\u0026rsquo;s story, the teacher- or psychologist-led analogue sessions help students process the narrative and deepen their understanding of the themes explored (e.g., perspective taking, empathy, impact hidden challenges). The group will reflect on the overall experience, their classroom dynamics and their sense of belonging within the group. This will enable contextualisation of the main learning themes.\u003c/p\u003e\n\u003cp\u003eAll necessary materials for these reflection sessions will be supplied by the trial team.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDescription of the comparator\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eControl classes will engage in standard school activities/routine lessons and will be provided the intervention in the beginning of the next school calendar year. \u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCriteria for discontinuing or modifying allocated intervention/comparator {15b}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAs the trial allocates intervention at the classroom level, discontinuation or modification of the allocated interventions in the trial may occur at the following levels:\u003c/p\u003e\n\u003col\u003e\n\u003cli\u003eIndividual student-level: A student may postpone or terminate active participation in the intervention if a) excused by the teacher or school administration in accordance with the school\u0026rsquo;s policies or procedures or, b) severe safeguarding concerns related to the intervention as determined by the Trial Steering Committee (TSC)\u003c/li\u003e\n\u003cli\u003eClass-level: An intervention class session may be postponed or terminated early due to a) operational constraints such as emergency closures, strikes or staff shortages experienced by the school or b) severe safeguarding concerns related to the intervention determined by the TSC\u003c/li\u003e\n\u003c/ol\u003e\n\n\u003cp\u003e\u003cstrong\u003eStrategies to improve adherence to intervention/comparator {15c}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe will develop Standard Operating Procedures (SOPs) around consenting procedures, data collection and management and intervention delivery to ensure fidelity and adherence to the protocol. All implementation researchers will fill out session logs to introduce a standard monitoring framework for data quality.\u003c/p\u003e\n\u003cp\u003eAlthough we don\u0026apos;t have any target tools to measure adherence and fidelity specifically, we will be monitoring fidelity and adherence to the intervention recording the number and content of each session using observation forms which will be filled out by researchers facilitating \u003cem\u003eLina\u003c/em\u003e lessons. \u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eConcomitant care permitted or prohibited during the trial {15d}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAs this is taking place within routine classes in schools, students and teachers will continue to receive all usual educational and wellbeing support delivered by schools. Given the vulnerable status of young participants in the trial, they will not be excluded from accessing additional interventions during the trial period. Information on the use of any additional support services availed of by students as a result of the trial within schools will be captured through trial assessments (e.g. Health Economics Inventory forms) and reviewed in the analysis to assess the cost of delivering the intervention in the schools.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cbr\u003e Ancillary and post-trial care {34}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis trial has been identified as a low-risk, school-based psychosocial intervention so we do not anticipate participants would require ancillary or post-trial care. In the event that participants do require additional support, they will continue to have access to the usual educational and mental health support available within their schools and we will follow school safeguarding policies and procedures at all times. The study is covered under the University of Birmingham\u0026apos;s standard research indemnity scheme for participants.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eOutcomes {16}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe trials will collect information from participants on a range of mental health, social and economic evaluation related outcomes including sense of belonging, symptoms of depression, social anxiety, loneliness, quality of life, stigma, social awareness and resource use. \u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003ePrimary outcome \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe primary outcome will be sense of belonging/ class climate as measured by the Delaware School Climate Survey- Student (DSCS-S) measured post intervention (8-10 weeks) and at follow-up. This is a 23-item student-report scale to measure the sense of belonging an individual feels within a classroom context (15). The scale is comprised of five subscales: Teacher-Student Relationships; Student-Student Relationships; School Safety; Fairness of the Rules and School Liking (16). Items are rated on a Likert scale, with negatively worded items reverse-scored. Subscale scores for Teacher\u0026ndash;Student Relationships, Student\u0026ndash;Student Relationships, School Safety, Fairness of the Rules, and School Liking are computed as the mean of their respective items. An overall school climate score is calculated as the mean of all 23 items. The DSCS-S is justified for measuring this outcome as it demonstrates strong psychometric validity and reliability in Portugal (17), Anglophone contexts e.g. United States (16), and in Eastern European settings e.g. Serbia (18) along with widespread international use in low resource settings. The wording of the items, in all three languages, has been adapted slightly to ask about the class climate, as opposed to the overall school climate. This is in order to make the measure sensitive to the climate of the specific classroom in which the intervention was delivered.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eSecondary outcomes \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn line with the developing \u003cem\u003eLina\u003c/em\u003e theory of change, secondary outcomes were selected to assess constructs anticipated to be affected by \u003cem\u003eLina. \u003c/em\u003eGeneral wellbeing may be increased via increased belonging or other aspects associated with \u003cem\u003eLina\u003c/em\u003e such as exposure to the arts. Social anxiety and depression were selected as symptoms of mental distress that are both some of the most commonly experienced in adolescents, and (in the case of \u003cem\u003esocial\u003c/em\u003e anxiety) most likely to be positively impacted by \u003cem\u003eLina\u003c/em\u003e. Social awareness represents an area of psychological resources expected to be positively impacted by \u003cem\u003eLina. \u003c/em\u003eLoneliness is sometimes conceptualised as the counterpoint to belonging and is expected to be positively impacted by the positive class environment created by \u003cem\u003eLina. \u003c/em\u003eFinally, the \u003cem\u003eLina\u003c/em\u003e story touches directly on mental health issues in a way designed to reduce stigma. Measure selection was strongly influenced by availability of prior validation with young people in PT (where specific regulatory constraints exist around measures that can be used with young people in school settings), and by availability of data on sensitivity to change. Thus, the following student-report measures were selected. For all questionnaires, the total score (sum of all items) is the unit of analysis. \u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003eWHO-5 Well-being Index is a 5-item measure of general well-being that has proven reliability and criterion validity amongst adolescents in the United Kingdom, Portugal and Czech Republic as part of a large cross-national validation study (19). Scores are transformed to a score from 0 to 100, with lower scores indicating worse well-being (20).\u003c/li\u003e\n\u003cli\u003ePatient Health Questionnaire-8 is an 8-item screening tool designed to assess the presence of depression symptoms (21). PHQ-8 has strong equivalence with PHQ-9, has been tested for reliability and validity in 27 European countries - including the United Kingdom, Portugal and Czech Republic (22) and has demonstrated high internal consistency when administered with adolescents from vulnerable settings (23). The total score can range from 0\u0026ndash;24, with a score of \u0026ge;10 indicative of clinical-level depression (21).\u003c/li\u003e\n\u003cli\u003eSocial Anxiety Scale for Adolescents (SAS-A) is an 18-item questionnaire measuring adolescents\u0026rsquo; social anxiety experiences in the context of peer relations (24). SAS-A has proven reliability and validity for Portuguese adolescents (25) and has been used in school-based screening of adolescents across France and Spain (26\u0026ndash;28) with acceptable internal consistencies and validity. It contains three subscales: Fear of Negative Evaluation, Social Avoidance and Distress-New and Social Avoidance and Distress-General. Total score ranges from 0-90 with a higher score indicating a higher level of social anxiety (24).\u003c/li\u003e\n\u003cli\u003eThe 4-item University of California Los Angeles (UCLA) Loneliness Scale is a revised and shorter version of the full UCLA tool (20 items) (29). The full UCLA scale demonstrated modest internal consistency in the assessment of loneliness in children and adolescents (30). This version of the UCLA has been recommended by the Office of National Statistics in the United Kingdom (30,31) as a strong measure of loneliness in youth aged 10-15 years, following adaptations. The tool has been translated and validated in Portugal and Slovakia with a modest internal consistency (32,33).\u003c/li\u003e\n\u003cli\u003eSocial-Emotional Learning Edition of the Strengths and Difficulties Inventory System [brief version] (SSIS SELb) Social Awareness subscale is a 4-item assessment that evaluates the social-emotional skills of children and adolescents in relation to their social awareness. It measures how much students take into account others\u0026rsquo; point of view, particularly those from different backgrounds (34). SSIS SELb was translated and validated for use among school-going adolescents in 6 European countries including Portugal with a strong measurement for reliability and structural validity, supporting its use for international research with appropriate adaptation and translation (34).\u003c/li\u003e\n\u003cli\u003ePeer Mental Health Stigmatisation Scale-Revised (PMHSS-R) Stigma Awareness subscale is 5-item assessment of individually held stigmatising beliefs. It is answered on a 5-point Likert scale of agreement (35). PMHSS-R has been developed in Ireland (35) and validated in European contexts (Spain) (36) but there is no country-specific validation for the United Kingdom, Portugal and Czech Republic. However, at the time of drafting this protocol, PMHSS-R is currently the only validated tool that assesses both awareness and agreement of stigma and was considered justified in use for measuring these outcomes in the trial.\u003c/li\u003e\n\u003cli\u003eEQ-5D-Y-3L is a child-friendly questionnaire to describe young peoples\u0026rsquo; health across five dimensions: Mobility; Looking After Myself; Doing Usual Activities; Having Pain or Discomfort; and Feeling Worried, Sad or Unhappy (37). Each dimension has three levels of response. The tool has been translated in Czech (38) and Portuguese (39) and demonstrates strong psychometric evidence for validity and reliability with adolescents in the United Kingdom (40) and among Portuguese speakers (39). \u003c/li\u003e\n\u003cli\u003eChild Health Utility-9D (CHU-9D) is a self-report measure of health-related quality of life suitable for 7- to 17-year-olds. It consists of 9 dimensions each measuring a different domain (worried, sad, pain, tired, annoyed, schoolwork, sleep, daily routine and activities). Each domain has 5 levels of severity. The CHU-9D has been locally translated for administration among young people in Portugal, Czech Republic (41) and the United Kingdom and demonstrated modest internal consistency and validity among children, adolescents and young adults within the UK and Portuguese speakers (39).\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eResource use data \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe will collect three groups of data for resource use in the economic evaluation. \u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003eFirst, we will collect data from teachers/psychologists on their time spent preparing and delivering\u003cem\u003e Lina\u003c/em\u003e and usual sessions. The data will be collected for three periods, i.e. at baseline (with 3 months recall), the end of 8-10 weeks intervention (with 8-10 weeks recall for control group and weekly data collection for intervention group after each \u003cem\u003eLina\u003c/em\u003e session), and 6 months follow up (with 6 months recall). In addition to time spent by teachers/psychologists, we will also collect data on other professionals\u0026rsquo; time spent (e.g. administrative staff, teaching assistants) on delivering \u003cem\u003eLina\u003c/em\u003e or usual sessions. We developed four Health Economics Inventory forms for data collection on time spent by teachers/psychologists and other professionals. \u003c/li\u003e\n\u003cli\u003eSecond, our research team will collect data on the quantity and costs of equipment used for delivering \u003cem\u003eLina\u003c/em\u003e sessions, including smartphones, routers, headphones, and paper-based materials. \u003c/li\u003e\n\u003cli\u003eThird, we will collect data on time spent by teachers/psychologists and other professionals (e.g. administrative staff, teaching assistants, counsellors) providing additional mental health/wellbeing support to students as well as managing students\u0026rsquo; disruptive behaviours. The data will be extracted from school records for the period from 3 months before baseline till the end of 6 months follow up. \u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eQualitative data \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFollowing completion of \u003cem\u003eLina\u003c/em\u003e, focus groups and interviews will be conducted with both student participants and teachers who were involved to collect implementation and experiential data.\u003c/p\u003e\n\n\u003cp\u003eFocus groups and interviews will be audio recorded and anonymised transcripts will be the data subject to analysis. For the purpose of data analysis, transcripts for 3 interviews, 1 focus group with young people, and 1 teacher focus group from each country will be translated initially and the UK, CZ, and PT teams will collaboratively devise a coding framework. This framework will then be used to conduct first-level data analysis separately in each country. Data will then be collated and analysed together by UK, CZ, and PT researchers collaboratively.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eImplementation evaluation data\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo further understand how \u003cem\u003eLina\u003c/em\u003e would be implemented as part of routine school activities, and to inform dissemination and further implementation strategies, an embedded implementation evaluation will be conducted both during the trial and after it is completed. The implementation evaluation will draw from multiple data sources, using a mixed methods design, to get a full insight into the barriers and facilitators that would affect\u003cem\u003e Lina\u003c/em\u003e delivery and learn how to increase reach and improve roll out. This evaluation will be conducted across trial schools in all three countries. \u003c/p\u003e\n\n\u003cp\u003eThe primary data sources will be:\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cem\u003eQuestionnaire measures completed by teachers\u003c/em\u003e - Teachers from intervention classes will complete questionnaires on feasibility (\u0026ldquo;Feasibility of Intervention Measure\u0026rdquo;), acceptability (\u0026ldquo;Acceptability of Intervention Measure\u0026rdquo;), and appropriateness (\u0026ldquo;Appropriateness of Intervention Measure\u0026rdquo;) (42) after each episode/session of \u003cem\u003eLina \u003c/em\u003eto give feedback on each session. They will then also complete these measures at post-intervention timepoint to feedback on the intervention as a whole.\u003c/li\u003e\n\u003cli\u003e\u003cem\u003eImplementation data provided by teachers\u003c/em\u003e - Teachers from intervention classes will answer three broad questions on \u003cem\u003eLina \u003c/em\u003e \u0026ldquo;what went well?\u0026rdquo;, \u0026ldquo;what didn\u0026rsquo;t go well?\u0026rdquo;, and \u0026ldquo;what could have gone better?\u0026rdquo;. These questions will be asked by the researcher after each session of \u003cem\u003eLina\u003c/em\u003e for immediate feedback on the delivery of that session. Teachers will also answer these questions, retrospectively, at the end of the intervention to give feedback on \u003cem\u003eLina\u003c/em\u003e as a whole.\u003c/li\u003e\n\u003cli\u003e\u003cem\u003eStructured observations\u003c/em\u003e - A researcher will be present to conduct structured observations of all \u003cem\u003eLina\u003c/em\u003e sessions. \u003cem\u003eFocus groups (teachers and psychologists)\u003c/em\u003e - Following the completion of \u003cem\u003eLina,\u003c/em\u003e teachers will be invited to participate in focus groups to elaborate on their experience of implementation , and give interactive feedback on potential strategies to facilitate implementation.\u003c/li\u003e\n\u003cli\u003e\u003cem\u003eFocus groups (young people)\u003c/em\u003e - Students from intervention classes who experienced \u003cem\u003eLina\u003c/em\u003e will be invited to participate in focus groups where they can elaborate on their lived experience of using the intervention and how its delivery could be improved. \u003c/li\u003e\n\u003c/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eData Collection Timepoints\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe baseline measures will be completed after the class has been randomised, but prior to the beginning of the intervention.\u003c/p\u003e\n\n\u003cp\u003eBaseline measures will be collected \u003cu\u003eat least\u003c/u\u003e one week before the first session of \u003cem\u003eLina\u003c/em\u003e. It is most likely that baseline data will be collected two weeks before the first \u003cem\u003eLina \u003c/em\u003esession, therefore allowing enough time to collect data from all students in the class. \u003c/p\u003e\n\n\u003cp\u003ePost-intervention measures will be collected between 8 and 10 weeks from the date of baseline assessments (allowing a 2 week time window, whilst accounting for the instances where classes hold multiple intervention sessions in a week). Six month follow up measures will be collected within four weeks (either side) of the date of six whole months since baseline assessments.\u003c/p\u003e\n\n\u003cp\u003eMeasures will be completed as part of the routine school day, within a class session. If a participant is absent from school, or data is missing for any reason, then the research team will have 3 weeks from the data collection time point to collect that data. \u003c/p\u003e\n\n\u003cp\u003eAll trial assessments will need to take place within the 2025/26 academic year. In the rare case that schools or classes are delayed in their delivery of \u003cem\u003eLina \u003c/em\u003eand final follow up falls outside of the summer academic term then follow-ups may need to take place sooner than 6 months post baseline.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eHarms {17}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eParticipation involves low expected risk e.g. emotional distress during data collection, safeguarding disclosures during the intervention, or minor physical injury during classroom activities. Risks will be mitigated through the use of age-appropriate measures, clear information about voluntary participation and withdrawal and clear Standard Operating Protocols to guide researchers on how to identify and manage risks sensitively when working with adolescents, and delivery in schools with existing safeguarding support. Researchers will monitor participants throughout all activities and may pause or stop data collection if concerns arise. Clear procedures are in place to guide measured responses to any harm identified or reported and escalate concerns to school safeguarding leads where required. All adverse events are recorded (expected, unexpected, related or unrelated), with serious events reported promptly to the research leadership and ethics committees within 24 hours.\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e \u003cstrong\u003eParticipant timeline {18}\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"626\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"4\" valign=\"top\" style=\"width: 385px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTRIAL PERIOD\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eEnrollment\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 284px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePost-randomization\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTIMEPOINT\u003csup\u003eb\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e-t\u003csub\u003ei\u003c/sub\u003e \u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003eto 0\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003et\u003csub\u003e0 \u003c/sub\u003e (Baseline)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003et\u003csub\u003e1 \u003c/sub\u003e(Post- intervention)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003et\u003csub\u003e2 \u003c/sub\u003e(6-months)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eENROLLMENT:\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 91px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 103px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 90px;\"\u003e\n \n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eEligibility screen\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAllocation/Randomisation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eInformed consent\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \u003cp\u003eX \u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eINTERVENTION/ COMPARATOR:\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003eLina \u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003elessons\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 194px;\"\u003e\n \u003cp\u003eX -----------------\u0026gt; X\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRoutine school lessons\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 194px;\"\u003e\n \u003cp\u003eX -----------------\u0026gt; X\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eASSESSMENTS\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(YOUNG PEOPLE):\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eDemographics\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \u003cp\u003eX \u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eDelaware School Climate Survey- Student \u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eWHO-5 Well-being Index \u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePatient Health Questionnaire-8\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSocial Anxiety Scale for Adolescents (SAS-A)\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eUniversity of California Los Angeles (UCLA) Loneliness Scale\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSocial-Emotional Learning Edition of the Strengths and Difficulties Inventory System [brief version] (SSIS SELb)\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePeer Mental Health Stigmatisation Scale-Revised (PMHSS-R)\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eHealth-related Quality of Life EQ-5D-Y-3L\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eChild Health Utility-9D (CHU-9D)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eIntervention (\u003cem\u003eLina\u003c/em\u003e) feedback \u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eInterviews and Focus Groups\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eASSESSMENTS (TEACHERS):\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eDemographics\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eHealth Economics Resource Inventory\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eImplementation evaluation form (Feasibility, Acceptability, Appropriateness) \u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eIntervention (\u003cem\u003eLina\u003c/em\u003e) feedback\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eFocus Groups\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 91px;\"\u003e\n \n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\n\u003cp\u003e\u003cstrong\u003eSample size {19}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSize of trial sample\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBased on an assumed small to medium effect size (Cohen\u0026rsquo;s d = 0.4), a conservative Intraclass Correlation Coefficient (ICC) of 0.1, which takes into account the clustering at the class and school level, and a design effect of 2.7, 40 classes per country will provide 90% power (alpha = 0.05).\u003c/p\u003e\n\u003cp\u003eThe analysable trial sample assumes an average cluster size of 18, (a total of 720 participants per country). To allow for an anticipated drop-out rate of 20%, an average cluster size of 22 will be recruited at baseline (i.e., average 22 adolescents per classroom), thus giving a total sample size of 880 per country. The cluster size of 22 at baseline takes into account the variability in class sizes within and across each country, and expected number of participants who opt out of the study.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eSize of interview and focus group sample \u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFor the post-trial interviews and focus groups it is predicted that there will be a maximum of 160 young people per country invited to participate in the evaluative qualitative work (up to 120 young people invited to a focus group, and 40 young people invited to be interviewed). \u003c/p\u003e\n\n\u003cp\u003eFor teachers, there is predicted to be 20 teachers per country eligible to be interviewed or invited to a focus group. \u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eRecruitment {20}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSampling technique\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn order to recruit 40 classes per country, we predict that around 10 schools per country will need to be recruited, with each contributing an average of 4 class cohorts. We anticipate there will be variations in the number of class cohorts available within individual schools across countries.\u003c/p\u003e\n\u003cp\u003eThis will represent an overall opportunistic sampling method, making use of schools who have indicated an interest in the \u003cem\u003eLina\u003c/em\u003e and have agreed to become a flagship school. However, we will aim to purposively recruit schools with higher levels of deprivation as deprivation is linked to greater risk of poor mental health. \u003c/p\u003e\n\n\u003cp\u003eIn PT, the percentage of Free and Reduced Cost School Meals will be used as an indicator of deprivation. Young people who come from the lowest economic socioeconomic status have free lunches (they are listed as A in the school support system) and young people from low, but slightly higher, socioeconomic status families pay 50% of the lunch (and they are listed as B in the school support system).\u003c/p\u003e\n\u003cp\u003eWe will aim to recruit schools with the highest numbers of students listed in category A for Free and Reduced School Meals.\u003c/p\u003e\n\n\u003cp\u003eIn CZ and the UK, schools will be recruited near to the respective research bases (University of Birmingham and Masaryk University), which both reflect urban areas, with high numbers of relatively disadvantaged schools. Although priority will be given to pragmatic considerations (ease of access, eagerness of school to participate), local knowledge will be used to preferentially shift recruitment towards more disadvantaged schools. In the UK, this is reflected by schools having a higher-than-average proportion of students meeting the low socioeconomic status criterion for additional school funding from the government (\u0026ldquo;pupil premium\u0026rdquo;), as available on government websites (\u0026asymp;\u0026gt;30%). In both countries it is reflected by relatively high levels of ethnic minority students, as ascertained based on local knowledge.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cu\u003e \u003c/u\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRecruitment of schools\u003cem\u003e \u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSchools will be identified, approached and recruited across the three countries using a number of different strategies that are adapted to the national context. In general, the trial team will make use of existing networks, conferences, seminars and learning events attended by headteachers and teachers to promote the study, and assess interest. Those schools that want to support the study will be offered to become a \u0026ldquo;flagship school\u0026rdquo; to support in the networking within educational networks about the intervention and the objectives of the trial. Flagship schools will be given the opportunity to become a trial school (i.e. a trial site from which we recruit classes and participants from), but this will not be mandatory. \u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003cstrong\u003eSample identification\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOnce a school has agreed to be a trial school then the trial team will support them to identify whole classes that have students that meet the eligibility criteria. We will work with schools to assess how best to deliver \u003cem\u003eLina\u003c/em\u003e within the routine school day, i.e. identify a specific subject or class that could integrate the intervention and be part of the regular school day. As an example, in the UK it is likely that the intervention will be delivered as part of Personal, Social, Health and Economic (PSHE) lessons which covers a range of topics related to personal development. However, schools can individually choose where they think \u003cem\u003eLina\u003c/em\u003e best fits within their curriculum.\u003c/p\u003e\n\n\u003cp\u003eThe variation of subjects and lesson content both across schools and across countries means that the trial team will take a pragmatic approach to delivery and support the schools in making tailored decisions. It is recommended to schools that each of the six \u003cem\u003eLina\u003c/em\u003e sessions are delivered weekly for six weeks within a single term. However, due to the pragmatic nature of the trial, and the understanding that schools (both within and between countries) structure lessons in different ways, schools may choose to deliver the sessions at different frequencies or across shorter or longer time periods (e.g., some schools may choose to deliver two sessions of \u003cem\u003eLina\u003c/em\u003e a week for three weeks). The variation in delivery will be collected as the observational data and form part of the analysis. Irrespective of the intervention delivery, follow up outcome measures will be collected at 8-10 weeks after baseline.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eInterview and focus group sampling \u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePurposive sampling will be used to identify individuals of interest to participate in the planned post-trial interviews and focus groups (that make up part of the implementation evaluation and exploration of lived experiences). \u003c/p\u003e\n\n\u003cp\u003eFor young people, individual interview data will be collected from particularly vulnerable students, who want to talk about \u003cem\u003eLina \u003c/em\u003e(i.e. have something to say), and have characteristics that make them more likely to have relatively extreme (good or bad) experiences of \u003cem\u003eLina\u003c/em\u003e. Focus group data will be collected from students who want to talk about \u003cem\u003eLina\u003c/em\u003e, for example because they have had a particularly good or bad experience of \u003cem\u003eLina. \u003c/em\u003eIn the UK the vulnerable students for interviews will be defined by three separate criteria: i) recipient of pupil premium ii) having special educational needs and disabilities (SEND) and iii) having experienced \u0026lsquo;notable social experiences\u0026rsquo; e.g. negative experiences like bullying and/or positive social experiences such as being part of an extracurricular club or society outside of school. Students will have the opportunity to self-identify with (any of) these characteristics and teachers will also be asked to recommend students. In PT and CZ, students for interviews will be identified based on discussion with teachers. In all countries, students will be given the opportunity to self-select for focus group participation, and students may also be recommended by teachers or by observing researchers.\u003c/p\u003e\n\n\u003cp\u003eFor teachers- all teachers who facilitated the use of \u003cem\u003eLina\u003c/em\u003e will be invited to attend an interview or focus group.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAssignment of interventions: randomisation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSequence generation: who will generate the sequence {21a}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRandomisation scheme \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe trial will employ a cluster randomised design, with class being the unit of randomisation. Whole classes will be randomised to either the \u003cem\u003eLina \u003c/em\u003earm or the control group arm.\u003c/p\u003e\n\n\u003cp\u003eThe trial statistician at Queen Mary University of London will use STATA to randomise a list of classroom IDs to either intervention or control conditions. IDs will then be assigned to classes in the order in which they are enrolled.\u003c/p\u003e\n\n\u003cp\u003eClasses within schools will be randomised at the same time (where possible) and the school and individual teachers will be informed of their allocation by the local research assistant or the trial manager. \u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eSequence generation: type of randomisation {21b}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eRandomisation will be stratified by country, and then stratified by blocks of 2 or 4. The randomisation scheme may be amended as and when the full list of participating trial schools is known. Any future amendment to the randomisation scheme will be there to ensure that there is at least one class in the \u003cem\u003eLina\u003c/em\u003e arm per school (important for school retention) and to ensure that there are comparable numbers of participants randomised to each of the trial arms.\u003c/p\u003e\n\n\u003cp\u003eRandomisation will occur only when: schools have agreed to be part of the trial; appropriate classes that meet the inclusion criteria have been identified; adolescents have agreed to the study and all students have been allocated to the class. Once these terms have been met then randomisation can be triggered. Randomisation will occur before participant baseline data collection. The allocation ratio will be 1:1. \u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAllocation concealment mechanism {22}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDue to the nature of the trial, allocation concealment can only be maintained at the level of data collection. To ensure allocation concealment, password-protected randomisation allocation lists generated by the statistician will be maintained in Excel files and shared only with the Trial Manager and unblinded researchers in each trial team responsible for intervention scheduling. Passwords for the excel sheets will be communicated via a secure separate channel and deleted afterwards to prevent accidental disclosure to blinded researchers responsible for facilitating trial assessments. Logs containing any data linking classroom-level information to concealment will be restricted to unblinded researchers until the end of the trial assessments (e.g. post-intervention and 6-month follow-up)\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eImplementation {23}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAs the unit of randomisation in this trial is the classroom, all students within participating classrooms will be enrolled into the trial, provided they have met the relevant consent criteria. The procedure is listed below:\u003c/p\u003e\n\u003col start=\"1\" type=\"1\"\u003e\n\u003cli\u003eThe trial team in each country will be responsible for enrolling eligible classrooms within recruited schools. \u003c/li\u003e\n\u003cli\u003eA list of classroom IDs will be produced and shared with the Trial Statistician who will generate the allocation sequence using block randomisation (blocks of two and four) to assign classrooms to intervention or control arms. IDs will then be assigned to classes in the order in which they are enrolled.\u003c/li\u003e\n\u003c/ol\u003e\n\n\u003cp\u003e\u003cstrong\u003eAssignment of interventions: blinding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eWho will be blinded {24a}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eBlinding\u003c/strong\u003e \u003c/p\u003e\n\u003cp\u003eDue to the nature of the intervention under investigation and the cluster design of the trial, blinding participants (and teachers) to their allocation will not be possible. Baseline data will be collected post-randomisation, but prior to the start of the intervention. Participants in the class will not be informed of allocation prior to baseline data collection, (although teachers will be aware due to pragmatic considerations around lesson planning, for example). \u003c/p\u003e\n\n\u003cp\u003eIn the UK trial, researchers facilitating the baseline, post-intervention and 6-months follow up will be blinded to allocation where possible. \u003c/p\u003e\n\u003cp\u003eDue to researcher capacity in Portugal and Czechia, blinding will not be possible at any of the post-intervention follow ups (i.e., T1 and T2).\u003c/p\u003e\n\n\u003cp\u003eThe statistician and health economists conducting the analysis will be unblinded at the time of analysis but corresponding analysis plans will be finalised and signed off before commencement of analysis.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eHow will be blinding be achieved {24b}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBlinded researchers will be determined prior to the start through the Trial Delegation log. To avoid any unblinding, efforts will be made to ensure that unblinded researchers are not responsible for coordination, allocation information will be stored separately from assessment material, will be password-protected and masked in any analysis datasets until the primary analysis is completed. \u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cbr\u003e Procedure for unblinding if needed {24c}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eUnblinding researchers to participant allocation may occur in the interest of participant safety e.g. if the knowledge of the participant\u0026rsquo;s allocation is necessary for the appropriate management of an adverse event or severe adverse event. Any such request would be formally documented in a trial file note, and reported to the Principal Investigator and Trial Manager.\u003c/p\u003e\n\n\u003cp\u003e\u003cbr\u003e\u003cstrong\u003eData collection and management\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePlans for assessment and collection of outcomes {25a}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll outcome measures used have been validated for use with adolescents. The list of outcome measures was decided upon thorough consultation with the Trial Management Group (TMG) and a panel of young co-researchers (see heading 12 for full list of outcome measures).\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eData Collection for Outcome Measures\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eElectronic case report forms (e-CRF) will be created to collect socio-demographic data and outcome data (separate versions for each timepoint) (these can be accessed on the ASP\u003cem\u003ebelong \u003c/em\u003eOpen Science Framework project page (43)). The e-CRFs will be hosted on smartphone-compatible software that will link to the online trial database (REDCap) through a unique participant number. At baseline, a record will be created in the database for each participant. Following baseline data collection, an individual URL will be created by the REDCap software for each participants\u0026rsquo; data row. At post \u003cem\u003eLina\u003c/em\u003e and follow up data collection timepoints, a bespoke application (built by the project team) will open the e-CRF linked to the correct URL when the corresponding participant number is entered. Participants will complete the measures on the smartphones provided by the study team (the same devices used to deliver the intervention). In the event of technical challenges with electronic data entry (e.g. Wi-Fi issues), paper forms will be used to complete the assessment.\u003c/p\u003e\n\n\u003cp\u003ee-CRFs will be completed as part of the routine school day, within a class session. They will be collected from all consenting students within that class at the same time, facilitated by the class teacher or a psychologist (PT) and a researcher (UK, CZ), who will offer support where needed around understanding questions in a consistent manner within each country context (i.e. explaining certain terminology within item wording that students query). If a participant is absent from school, or data is missing for any reason, then the research team will have 3 weeks from the data collection time point to collect that data. \u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003ePlans to promote participant retention and complete follow-up {25b}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe will not be collecting any individual-level contact information for participants except where necessary to coordinate data collection for people actively opting into interviews and/or focus groups. Efforts for participant retention and mitigating attrition will therefore be on a school-level. We have worked on establishing strong relationships with schools and teachers through regular communication, several networking opportunities, and emphasising a strong sense of collaboration. Further, we will be flexible with scheduling lessons to accommodate the academic calendar/exam time, or any other school events.\u003c/p\u003e\n\u003cp\u003eNo data will be collected from students who withdraw themselves or whose parents withdraw them from the trial. Furthermore, in the event that a student was to leave the school or be transferred to a different class within the same school during the intervention, they would cease to receive the intervention, and no further data would be collected from them.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eData management {26}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe primary mode of data capture will be through electronic Case Report Forms (e-CRFs) administered on smartphones via REDCap (Research Electronic Data Capture) which is a secure, web-based system designed for building and managing research data. If REDCap is unavailable (e.g. device malfunction, connectivity issues), paper Case Report Forms (CRFs) will be used. Paper CRFs will be entered into REDCap at the earliest opportunity, with the paper copy stored securely at each site in a locked cabinet and stored separately from any identifiable enrolment information. Each participant survey will be linked to a unique participant ID (PID), and the follow-up assessments are linked to it. Paper-based data can be transferred between individual sites (e.g. schools) to the central site but will never leave the central site (e.g. University of Birmingham in UK, Masaryk University in CZ and Acad\u0026eacute;mico Torres Vedras (ATV) in Portugal). Access to the REDCap portal will be granted to designated and trained researchers at each site for the manual data entry of paper CRFs into the online portal. Site leads and researchers will be responsible for first-level quality control of the data entry and checks. The trial manager will oversee routine monitoring and any data errors in the database will be queried and resolved with the relevant site team. Once data is entered into REDCap, data exports can be produced through reports for data verification and analysis by the Trial Statistician. \u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eConfidentiality {33}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe trial will comply with the requirements of the UK Data Protection Act 2018, as standard, with regards to the collection, storage, processing and disclosure of personal information and will uphold the Act\u0026rsquo;s core principles throughout the study, and be UK General Data Protection Regulation (GDPR) compliant. As all trial data (from all three countries) will be stored in the UK, the relevant national legislation of the UK will be followed:\u003c/p\u003e\n\n\u003cp\u003eAll data will be confidential at the point of collection, linked to participants via unique ID numbers. Identifying information (participant full names and contact details) will only be collected for participants (students and teachers) in the qualitative and implementation evaluations, and only when necessary (e.g. to arrange data collection with a student, which may otherwise be arranged via the class teacher). Personal information will be stored in password protected spreadsheets at the local research site (University of Birmingham, Masaryk University, Acad\u0026eacute;mico Torres Vedras) and linked to research data via the unique ID.\u003c/p\u003e\n\u003cp\u003eInterviews and focus groups (qualitative and implementation evaluations) will be audio recorded and these data will be potentially identifying. Recordings will be stored securely at each research site until transcription, when any potentially identifying information will be removed (transcripts will be anonymous). Following verification of the transcripts, the audio data will be deleted. Only anonymous data will be shared across research sites for analysis.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eStatistical methods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical methods for primary and secondary outcomes {27a}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical Analysis \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData for the three trials will be analysed separately (by country), before later being pooled for overall analysis.\u003c/p\u003e\n\n\u003cp\u003eParticipant level socio-demographic data and cluster level (classroom) data will be summarised at baseline for both arms of the trial.\u003c/p\u003e\n\n\u003cp\u003eThe primary outcome is the Delaware Class Climate score at the end of \u003cem\u003eLina\u003c/em\u003e delivery (8-10 weeks post baseline and follow-up). This will be compared between \u003cem\u003eLina\u003c/em\u003e and control groups using a linear mixed effects model with a random effect for classroom and school, allowing for the clustering of children, within classes, and within schools. The model will include baseline level of the Delaware Class Climate as a covariate, as well as demographics (that are known to affect outcome). The analysis will use intention to treat by including all participants in the arm to which they were randomised, whether or not they completed the \u003cem\u003eLina\u003c/em\u003e programme and including all students in the analysis by using multiple imputation. We will set out in the Statistical Analysis Plan (SAP) how missing data will be handled, including planned sensitivity analyses.\u003c/p\u003e\n\n\u003cp\u003eSecondary outcomes are WHO-5, PHQ-8, SAS-A, UCLA Loneliness Scale, SSIS SELb, PMHSS-R, EQ-5D-Y-3L and CHU-9D all measured at post-intervention (T1) and 6 months post baseline (T2). Each variable will be analysed using a generalised linear mixed effects model with a link function appropriate to the outcome distribution, with random effects for classroom and school. All models will include the baseline value of the outcome.\u003c/p\u003e\n\n\u003cp\u003eA full statistical analysis plan (SAP) will be developed prior to exporting data from the database and reviewed by the trial steering committee. Data analysis will not be conducted prior to final sign off of the SAP. The SAP will be made publicly available prior to data lock. \u003c/p\u003e\n\n\u003cp\u003eOnce country level data has been analysed, then data from across the three countries will be pooled and analysed as one dataset. This will follow analysis as described above but with further level of clustering at the country level. The full analysis plan for the pooled analysis will also be described in the SAP.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eEconomic Evaluation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe will conduct an economic evaluation alongside the three trials aiming to assess the cost effectiveness of Lina in comparison with usual lessons from a school perspective. The time horizon for the evaluation will be from the point of randomization until the 6-months follow-up. Intention-to-treat analysis will be applied. \u003c/p\u003e\n\n\u003cp\u003eThe primary outcome for our economic evaluation is the Quality Adjusted Life Years (QALYs), to be converted from the CHU-9D data by applying for the UK tariff (44). Secondary outcomes include the EQ-5D-Y-3L and the Delaware Class Climate score. The outcomes data will be collected at baseline, post-intervention, and 6 months follow up using the e-CRFs.\u003c/p\u003e\n\n\u003cp\u003eResource use includes three groups, i.e. (1) time spent by teachers/psychologists on preparing and delivering\u003cem\u003e Lina\u003c/em\u003e and usual sessions as well as other professionals\u0026rsquo; time spent on delivering \u003cem\u003eLina \u003c/em\u003eand usual sessions, (2) resource use for providing necessary equipment to deliver Lina sessions and (3) time spent by teachers/psychologists and other professionals on providing additional support to students as well as managing students\u0026rsquo; disruptive behaviours. We will collect relevant unit cost data to convert the quantity of resource use for each item to monetary values. The cost for resource use will be presented at student and time point level (i.e. baseline, immediately after intervention, and 6-months follow-up). We will explore the appropriate approach to handle missing values in costs and outcome data. No discounting will be required for costs and outcomes data. \u003c/p\u003e\n\n\u003cp\u003eA cost utility analysis will be performed on each country\u0026rsquo;s data to estimate the incremental costs of \u003cem\u003eLina\u003c/em\u003e compared to usual lessons per additional QALY gained (or the Incremental Cost-Effectiveness Ratio (ICER)). We will report the uncertainties around the point estimate of the ICER. Also, the point estimate will be compared against the country specific willingness-to-pay threshold(s). We will pool data from the three countries together to conduct a multiple-country cost utility analysis. A few sensitivity analyses will be performed including (1) using the EQ-5D-Y-3L and the Delaware Class Climate score as outcome measures (2) conducting economic evaluation under alternative scenarios related to implementation (e.g. frequency of session delivery) to help contextualise the findings for future implementation (3) applying for alternative approach(es) to handle missing values. \u003c/p\u003e\n\n\u003cp\u003eA Health Economic Analysis Plan will be signed off before the start of the economic evaluation. \u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWho will be included in each analysis {27b}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll randomised clusters (i.e. classroom) and their enrolled participants will be included in the primary analyses according to the intention-to-treat (ITT) principle, whereby participants will be analysed in the group to which their classroom was originally allocated (i.e. control or intervention).\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eHow missing data will be handled in the analysis {27c}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAnalysis will follow the intention-to-treat principle, meaning all participants will be analysed in the groups to which their classes were assigned, regardless of protocol deviations where contamination may have occurred. Any protocol deviation will be reported to the Trial Manager and formally documented. \u003c/p\u003e\n\u003cp\u003eThe proportion of missing data from each instrument in the trial assessments (i.e. student and teacher CRFs) will be summarised across assessment timepoints and their reasons will be described and discussed keeping in mind contextual realities within each trial site. \u003c/p\u003e\n\n\u003cp\u003eMissing data will be handled by multiple imputation by chained equations using the MI package in STATA and efforts will be made to ensure that imputed values stay within the valid range of each questionnaire. Results from the imputed dataset will then be combined using Rubin\u0026rsquo;s rules to produce final estimates that account for uncertainty due to missing data. \u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eMethods for additional analyses (e.g. subgroup analyses) {27d}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAdditional and subgroup analyses will be fully detailed in the Statistical Analysis plan, including sensitivity analyses to examine the impact of missing data imputation.\u003c/p\u003e\n\n\u003cp\u003eSubgroup analyses will explore differential treatment effects across genders and across high (top quartile) versus not high (lower three quartiles) baseline levels of social anxiety (SAS-A).\u003c/p\u003e\n\n\u003cp\u003eThe effect of adherence on sense of belonging (DCCS) will be examined via comparison of participants who received \u0026ldquo;sufficient\u0026rdquo; \u003cem\u003eLina \u003c/em\u003eto those that did not receive \u003cem\u003eLina \u003c/em\u003eor did not complete \u0026ldquo;sufficient\u0026rdquo; \u003cem\u003eLina. \u0026ldquo;\u003c/em\u003eSufficient\u0026rdquo; \u003cem\u003eLina \u003c/em\u003eis defined as at least 4 \u003cem\u003eLina \u003c/em\u003esessions, including the last 2 and either the first or second (based on the content of each session in the context of current knowledge on mechanisms of change).\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eInterim analyses {28b}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo interim analysis will be conducted. A trial steering committee composed of relevant cross-disciplinary professionals from the Czech Republic, Portugal and the UK (4 members), will have the power to terminate the trial based on regular reports on implementation, including adverse events.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eProtocol and statistical analysis plan {5}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study protocol will be made publicly accessible through publication in a peer-reviewed journal as well as the ISRCTN record (https://www.isrctn.com/ISRCTN11613092). The trial Statistical Analysis Plan (SAP) will be finalised before the database lock and published on University of Birmingham\u0026rsquo;s OSF record as well as to the study protocol as an update at a later stage. \u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eOversight and monitoring\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComposition of the coordinating centre and trial steering committee {3d}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe trial manager is based at Queen Mary University of London, where trial statistics and health economist teams are also based. These researchers will not play a direct role in data collection, but will form part of the Trial Management Group (TMG). The TMG will additionally comprise leads of the teams carrying out \u003cem\u003eLina \u003c/em\u003eimplementation in each country, and at least one representative from each team actually carrying out implementation on the ground. The two design leads of \u003cem\u003eLina\u003c/em\u003e will also be part of the TMG. The TMG will meet weekly for the duration of the trial. \u003c/p\u003e\n\u003cp\u003eThe trial steering committee (TSC) is independent of the TMG. It includes key professions relevant to the trial and its members are distributed among the 3 participating countries. A trialist and statistician is based in the UK and will independently review the SAP. An education practitioner with additional experience in research is based in the Czech Republic. A psychologist with experience in youth mental health is based in Portugal. Finally, a youth worker from the UK will represent both lay and youth voices.\u003c/p\u003e\n\u003ch3\u003e\u003c/h3\u003e\n\u003cp\u003eThe TSC will meet once before the trial commences and from then on, at 3\u0026ndash;6-month intervals until data collection and analysis are complete. The committee will receive monthly reports on ongoing implementation, including any adverse events and will have the responsibility to call exceptional meetings should any concerns arise. Following their activity, they will produce a final report summarising their work and any lessons learned.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eComposition of the data monitoring committee, its role and reporting structure {28a}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe do not have a separate Data Monitoring Committee, but the Trial Steering Committee will also act as the Data Monitoring and Ethics Committee (DMEC) and will be responsible for the review of the safety reports, e.g., number of serious adverse events.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eFrequency and plans for auditing trial conduct {29}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOversight will be maintained through regular (weekly) virtual check-ins and in-person site visits to the trial sites in the United Kingdom, Portugal and Czech Republic conducted by the Trial Manager (from Queen Mary University London) to ensure adherence to the protocol, data quality, trial procedures and documentation.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eProtocol amendments {31}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAny important protocol modifications (e.g. changes to eligibility criteria, outcomes, analysis plans, or trial procedures) will be communicated to and discussed with the Trial Management Group (includes the Chief Investigator, site lead, trial lead and manager, site researchers, statistician and health economist) and the Trial Steering Committee (TSC). Amendments will be updated in the trial registry (ISRCTN), and shared with trial researchers. All approved amendments will be documented with version control.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDissemination policy {8}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTrial findings will be disseminated following the ASP\u003cem\u003ebelong \u003c/em\u003eprogramme\u0026rsquo;s dissemination and communication plan, which is reviewed and revised regularly and comprises a deliverable of the project, publicly available via the European Commission. The plan includes a commitment to fully open access publications.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis trial has been designed to evaluate the effectiveness of \u003cem\u003eLina,\u0026nbsp;\u003c/em\u003ea novel, game-based digital intervention intended to improve classroom-level belonging among children ages 12-13 across three European countries. As a cluster Randomised Controlled Trial with a pragmatic approach, the study design and procedures have been intentionally aligned within routine educational systems and structures to improve recruitment rates and operational feasibility.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn selecting the unit of randomisation, we weighed up the increased risk of contamination, which would come with class as the unit of randomisation, with the expectation that our recruitment and retention would be greatly facilitated by ensuring that all involved schools had some classes engaged with the intervention throughout. Particularly given the non-explicit nature of the \u003cem\u003eLina\u003c/em\u003e intervention, which aims to improve class climate and belonging by the specific experiences of collaboration acquired by experiencing \u003cem\u003eLina\u003c/em\u003e together, we judged the risk of contamination to be relatively small compared to that of the expected recruitment and retention challenges that would have come from using school as a unit of randomisation.\u003c/p\u003e\n\u003cp\u003eDespite the intention for trial to be as similar as possible across the three countries, local contexts have required substantial specific considerations. Some of these have been integrated into the overall design, and others have led to country-specific procedures. For example, the core requirement for prior local validation of any student-facing questionnaires used in Portugal was one of the primary criteria we considered in selection of our outcome measures, and doing this has allowed us to maintain consistency in effectiveness outcome measures across countries. However, the legal requirement in Portugal for any intervention in the realm of psychological wellbeing (i.e. that could be badged as psychotherapeutic) to be administered by psychologists has required a different plan for implementation in Portugal relative to the other sites. When judging where to make country-specific modifications and where to push for consistency, we considered the long-term picture of likely implementation \u0026ldquo;in the wild\u0026rdquo;. Thus, where country-specific context suggested that a particular scenario would likely be relevant to long-term use of \u003cem\u003eLina\u003c/em\u003e in that setting (e.g. the Portuguese example of needing psychologists to implement the programme), we were more inclined to make those country-specific modifications to trial design.\u003c/p\u003e\n\u003cp\u003eBlinding was an issue which we regularly and widely debated within our TMG. Given the nature of the intervention, neither students, teachers or observing researchers can be blind to the intervention versus control group allocation. However, we had originally intended that researchers collecting data would be blind to the allocation. During the detailed process of laying down scheduling and teams in each implementation site however, it quickly became apparent how challenging it would be to keep any team members blind to allocation. We are aiming to achieve this where possible, but it is highly dependent on the practical set-up of each implementing team. And in the eventuality of any illness or other unexpected events within the teams, it is likely that at least some of the blinding will be jeopardised. We also considered maintaining the statistician conducting the analysis blind to allocation. However, in the context of the additional pragmatic challenges (resource demands) that would entail, we deemed that the prior full specification of the statistical analysis plan would appropriately minimise that risk of bias.\u003c/p\u003e\n\u003cp\u003eAs the first evaluation of any Augmented Social Play intervention post early stage piloting of a \u003cem\u003eLina\u003c/em\u003e, proof-of-concept, these trials will be definitive in terms of assessing the strength and scope of the benefits that may be mediated by ASP. Although ASP, including \u003cem\u003eLina,\u0026nbsp;\u003c/em\u003erepresents an entirely novel combination of active elements, each of these (e.g. fictional story, collaborative puzzle solving, mobile-device mediated, evidence-based psychotherapeutic techniques) is well known within its primary disciplinary field. Results of these trials therefore have the potential to stimulate exciting new transdisciplinary work towards securing youth mental health and wellbeing, within a specific ASP context and beyond.\u003cstrong\u003e\u003cbr\u003e\u003c/strong\u003e\u003cstrong\u003e\u003cbr\u003e\u0026nbsp;Trial status\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eProtocol version number:\u003c/strong\u003e v1.0\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eProtocol Date:\u003c/strong\u003e 12 January 2026\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDate recruitment started:\u003c/strong\u003e 22 September 2025\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eApproximate date recruitment will be complete:\u003c/strong\u003e 16 January 2026\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cbr\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"568\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAE\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003eAdverse events\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eASP\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003eAugmented Social Play\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCRFs\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003eCase report forms\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCZ\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003eCzechia\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eDMEC\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003eData Monitoring and Ethics Committee\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eeCRFs\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003eElectronic case report forms\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eGDPR\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003eGeneral Data Protection Regulation\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eICER\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003eIncremental cost-effectiveness ratio\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eICC\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003eIntraclass correlation coefficient\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePID\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003eParticipant ID\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePSHE\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003ePersonal, Social, Health and Economic education\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePT\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003ePortugal\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eQALYs\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003eQuality-adjusted life years\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eREC\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003eResearch Ethics Committee\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSAE\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003eSerious adverse Event\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSEND\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003eSpecial educational needs and disabilities\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSAP\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003eStatistical analysis plan\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTMF\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003eTrial Master File\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTMG\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003eTrial Management Group\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTSC\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003eTrial Steering Committee\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eUK\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 490px;\"\u003e\n \u003cp\u003eUnited Kingdom\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe would like to thank the group of 10 young people aged 14-16 years known to our ASPbelong consortium as \u0026ldquo;adolescent coresearchers\u0026rdquo; for reviewing trial measures. \u003c/p\u003e\n\n\u003cp\u003eStaff and young people at All Saints Youth Project in Birmingham supported interview schedule development.\u003c/p\u003e\n\n\u003cp\u003eRaynes Park High School in London supported a mock trial of the Lina trial in which a number of aspects of data collection were piloted. Thanks also to RMG Associates for facilitating this relationship.\u003c/p\u003e\n\n\u003cp\u003eWe would like to acknowledge the contribution of all researchers and students who supported the review of trial design and data collection procedures across participating sites and academic partners; University of Birmingham (interns - Max Bawden, Jessica Large, and Monica Patel; and research assistants), Acad\u0026eacute;mico Torres Vedras (Ana Sofia Rodrigues, Ana Maria Rom\u0026atilde;o, Ana Rita Ferreira, Catarina Chaves, Sofia Saldanha and Vanda Sousa), Masaryk University (Ale\u0026scaron; Přib\u0026iacute;k, Diana Turčekov\u0026aacute;, Martina Střechov\u0026aacute;, Barbora Prikrylov\u0026aacute;, Krist\u0026iacute;na Tomankov\u0026aacute;) and Queen Mary University of London (Sarah Bourdin).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions {3a}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eK.W. is the Chief Investigator; she conceived the study, led the proposal and protocol development. T.M. contributed to protocol development and writing, led implementation in the United Kingdom, and led the implementation evaluation. O.Q. is the trial manager and contributed to protocol development and writing along with P.M. and V.B. who is the trial oversight lead. A.B., G.M., V.B., V.C., and A.S. contributed to study design and to development of the proposal. A.F. led implementation in the United Kingdom, and the qualitative evaluation. V.C., P.B., and M.M. led implementation in Portugal. A.S., A.P., T.H., and C.S. led implementation in Czechia. B.S. is the trial statistician and developed the statistical analysis plan. Y.F. is the health economist and led the economic evaluation. N.M. supported implementation in the United Kingdom and led project management. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSources of funding and other support {7a}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding and support in kind:\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"601\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 301px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eFunder(s)\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003eNames and contact details of organisations providing funding and/or support in kind for this trial\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 301px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eFinancial and non-financial support given\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 301px;\"\u003e\n \u003cp\u003eEU Horizon Europe\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 301px;\"\u003e\n \u003cp\u003eProvided funding for the ASP-Belong programme, including the cluster RCT\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 301px;\"\u003e\n \u003cp\u003eUK Research \u0026amp; Innovation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 301px;\"\u003e\n \u003cp\u003eProvided funding for the ASP-Belong programme, including for the cluster RCT\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 301px;\"\u003e\n \u003cp\u003eUniversity of Birmingham \u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 301px;\"\u003e\n \u003cp\u003eStudy sponsorship and substantive employer of Chief Investigator\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 301px;\"\u003e\n \u003cp\u003eQueen Mary University of London \u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 301px;\"\u003e\n \u003cp\u003eSubstantive employer of Work Package lead, statistician, health economist and trial manager \u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 301px;\"\u003e\n \u003cp\u003eATV - Acad\u0026eacute;mico de Torres Vedras\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 301px;\"\u003e\n \u003cp\u003eSubstantive employer of Portuguese implementers and support researchers\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 301px;\"\u003e\n \u003cp\u003eMasaryk University\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 301px;\"\u003e\n \u003cp\u003eSubstantive employer of Czech implementers and support researchers\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 301px;\"\u003e\n \u003cp\u003eTrial schools\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 301px;\"\u003e\n \u003cp\u003ePermissions to conduct the trial on school premises with school staff and students. Some support costs and resources provided. \u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\n\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials {6}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData will be made open access by the time of publication of corresponding results at the latest.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate {30}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe University of Birmingham Science and Technology Ethics Committee has given a favourable ethical opinion for the three trials. Relatedly the University of Birmingham is also acting as the sole sponsor.\u003c/p\u003e\n\u003cp\u003eLocal approvals have been sought from institutional ethics committees (IECs) in Portugal and Czechia: Acad\u0026eacute;mico Torres Vedras and Masaryk University, respectively.\u003c/p\u003e\n\n\u003cp\u003eDetails of all ethical approvals are as follows:\u003c/p\u003e\n\u003col start=\"1\" type=\"1\"\u003e\n\u003cli\u003e\u003cstrong\u003eUK - Approved 06/05/2025\u003c/strong\u003e\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eScience, Technology, Engineering and Mathematics Committee\u003c/p\u003e\n\u003cp\u003eUniversity of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom\u003c/p\u003e\n\u003cp\u003e+44 (0)121 414 3344\u003c/p\u003e\n\u003cp\[email protected])\u003c/p\u003e\n\u003cp\u003eRef: ERN_3004-May2025\u003c/p\u003e\n\n\u003col start=\"2\" type=\"1\"\u003e\n\u003cli\u003e\u003cstrong\u003ePT - Approved 08/09/2025\u003c/strong\u003e\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eComiss\u0026atilde;o de \u0026Eacute;tica e Deontologia da Faculdade de Psicologia\u003c/p\u003e\n\u003cp\u003eFaculdade de Psicologia, Alameda da Universidade, Lisboa, 1649-013, Portugal\u003c/p\u003e\n\u003cp\u003e+351 217 943 655\u003c/p\u003e\n\u003cp\[email protected]\u003c/p\u003e\n\u003cp\u003eRef: N/A\u003c/p\u003e\n\n\u003col start=\"3\" type=\"1\"\u003e\n\u003cli\u003e\u003cstrong\u003eCZ - Approved 18/09/2025\u003c/strong\u003e\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eEtick\u0026aacute; Komise pro v\u0026yacute;zkum Masarykovy Univerzity\u003c/p\u003e\n\u003cp\u003eResearch Ethics Committee at Masaryk University, Masarykova Univerzita, Žerot\u0026iacute;novo n\u0026aacute;m. 617/9, Brno 602 00, Česk\u0026aacute; republika, Brno, 602 00, Czech Republic\u003c/p\u003e\n\u003cp\u003e+420 549 49 6290\u003c/p\u003e\n\u003cp\[email protected]\u003c/p\u003e\n\u003cp\u003eRef: EKV-2022-090\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable. No identifiable individual participant data will be published.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCompeting interests {7b}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eHards E, Loades ME, Higson-Sweeney N, Shafran R, Serafimova T, Brigden A, et al. Loneliness and mental health in children and adolescents with pre-existing mental health problems: A rapid systematic review. British Journal of Clinical Psychology [Internet]. 2022 Jun 1;61(2):313\u0026ndash;34. Available from: https://doi.org/10.1111/bjc.12331\u003c/li\u003e\n\u003cli\u003eG\u0026ouml;kmen Arslan PhD. School belongingness, well-being, and mental health among adolescents: exploring the role of loneliness. Aust J Psychol [Internet]. 2021;73(1):70\u0026ndash;80. Available from: https://doi.org/10.1080/00049530.2021.1904499\u003c/li\u003e\n\u003cli\u003eEugene DR. 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Available from: https://doi.org/10.1186/s13012-017-0635-3\u003c/li\u003e\n\u003cli\u003eOpen Science Framework. Open Science Framework. 2024. ASPbelong Project. \u003c/li\u003e\n\u003cli\u003eStevens K. Valuation of the Child Health Utility 9D Index. Pharmacoeconomics [Internet]. 2012;30(8):729\u0026ndash;47. Available from: https://doi.org/10.2165/11599120-000000000-00000\u003cstrong\u003e\u003c/strong\u003e\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"trials","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"trls","sideBox":"Learn more about [Trials](http://trialsjournal.biomedcentral.com/)","snPcode":"13063","submissionUrl":"https://www.editorialmanager.com/trls","title":"Trials","twitterHandle":"MedicalEvidence","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Adolescent mental health, Classroom belonging, Loneliness, Augmented social play, School-based intervention, Cluster randomised controlled trial, Digital health, E-health","lastPublishedDoi":"10.21203/rs.3.rs-8595707/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8595707/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e• \u003cstrong\u003eBackground:\u003c/strong\u003e\u003cbr\u003e\nMental ill-health and loneliness represent major challenges for today’s youth, exacerbated by unprecedented societal demands, including concurrent socialisation in physical and digital worlds. A strong sense of belonging can buffer against these challenges, and in adolescents is largely constituted in schools. Augmented Social Play (ASP) involves smartphone-led cooperative face-to-face gameplay which integrates immersive storytelling, augmented reality, and evidence-based psychology to strengthen belonging. Building on this foundation, \u003cem\u003eLina\u003c/em\u003e is a multi-session intervention designed for classroom-based delivery during routine school lessons.\u003c/p\u003e\n\u003cp\u003e• \u003cstrong\u003eMethods:\u003c/strong\u003e\u003cbr\u003e\nThree parallel hybrid type II cluster pragmatic Randomised Controlled Trials will be conducted in secondary schools in Czechia, Portugal and the UK. The trials will examine the effectiveness of \u003cem\u003eLina\u003c/em\u003e - compared to standard lessons - in strengthening classroom belonging, reducing symptoms of mental ill-health and improving wellbeing, loneliness and stigma. 40 classes of students whose modal age is 12-13 years will participate in each country. Effectiveness will be examined on completion of \u003cem\u003eLina\u003c/em\u003e and after 6-months, using the student-report Delaware School Climate Survey, the Social Anxiety Scale for Adolescents, the Patient Health Questionnaire-8, the Social Awareness subscale of the Social-Emotional Learning Edition of the Strengths and Difficulties Inventory System, the WHO-5 Well-being Index, the UCLA Loneliness Scale and a tailored version of the Peer Mental Health Stigmatisation Scale-Revised. To examine cost-effectiveness, quality of life will be measured in a corresponding manner, using the Child Health Utility 9D and the EQ-5D-Y-3L, and analysed alongside bespoke resource-use inventories, completed via teachers and/or school records. An embedded developmental evaluation of implementation will draw on researcher observations of \u003cem\u003eLina\u003c/em\u003e, teacher-reported Feasibility, Acceptability and Appropriateness of Intervention questionnaires and teacher focus groups. A second developmental phase of implementation evaluation will follow the effectiveness trial, while control classes do \u003cem\u003eLina\u003c/em\u003e with their teachers. An integrated qualitative evaluation will examine students’ experiences of \u003cem\u003eLina\u003c/em\u003e using individual interviews and focus groups, including a particular focus on students with characteristics that put their sense of belonging at risk.\u003c/p\u003e\n\u003cp\u003e• \u003cstrong\u003eDiscussion:\u003cbr\u003e\n\u003c/strong\u003eFindings will speak to the potential impact of \u003cem\u003eLina\u003c/em\u003e on youth mental health. They will also inform \u003cem\u003eLina\u003c/em\u003e implementation guidance for diverse national and international school contexts.\u003c/p\u003e\n\u003cp\u003e• \u003cstrong\u003eTrial Registry Information:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis trial is prospectively registered with ISRCTN (Identifier: ISRCTN11613092), registered on 15 September 2025, https://doi.org/10.1186/ISRCTN11613092\u003c/p\u003e","manuscriptTitle":"Three cluster randomised controlled trials in Portugal, Czechia and the United Kingdom to test the effectiveness and cost-effectiveness of an augmented social play intervention in schools to support real- world connection and sense of belonging (Lina trial protocol)","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-10 09:47:41","doi":"10.21203/rs.3.rs-8595707/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-04-08T15:56:50+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-08T15:56:18+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"7894898297631008935903474547836421203","date":"2026-04-05T18:45:52+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-05T18:40:06+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-05T13:25:10+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-02-05T07:45:08+00:00","index":"","fulltext":""},{"type":"submitted","content":"Trials","date":"2026-02-04T09:51:59+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"trials","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"trls","sideBox":"Learn more about [Trials](http://trialsjournal.biomedcentral.com/)","snPcode":"13063","submissionUrl":"https://www.editorialmanager.com/trls","title":"Trials","twitterHandle":"MedicalEvidence","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"f83e8baf-b105-4b41-908a-4d1736b24bea","owner":[],"postedDate":"April 10th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-09T22:39:30+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-10 09:47:41","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8595707","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8595707","identity":"rs-8595707","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}