Active Components in Digital Health Interventions for Sleep among Adolescents: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

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Though sleep problems are common in adolescents, limited research has focused on this age group. The appropriateness of DHIs for sleep promotion or insomnia treatment in adolescent populations, along with the active components associated with effective interventions, needs to be assessed. This review evaluated effective DHIs for sleep among adolescents and distilled their active components. Methods Randomized Controlled Trials (RCTs) were selected from OVID (Medline), CINAHL, Web of Science, SCOPUS, PsycINFO, and Embase databases from their inception to June 30, 2023, and updated in May 2024. Adolescence was defined as the phase of life stretching between childhood and adulthood (10 to 24 years old). Results Nine studies were identified, involving 9238 participants, of whom n = 4498 (47.8%) were females, between 12 and 24 years old (Mean: 15.6 years). Eight studies focused on digital cognitive behavioural therapy for insomnia dCBT-I, and one study focused on a holistic lifestyle DHI. Most studies delivered the DHI unguided using automatic messages (n = 4; 44.4%). dCBT-I for adolescents demonstrated a medium positive effect (n = 5; g =- 0.64, p = 0.01) on subjective sleep quality immediately after treatment. Results suggested that active components of effective dCBT-I for adolescents are cognitive restructuring, mindfulness, stimulus control sleep, and optional sleep restriction technique. Conclusions The findings suggest that dCBT-I could be beneficial for insomnia and comorbid mental health in adolescents. Possible active component interventions may include a sleep diary, as part of education, cognitive restructuring, mindfulness, and stimulus control. Biological sciences/Psychology Health sciences/Diseases Health sciences/Health care Scientific community and society/Social sciences Digital-health-intervention sleep insomnia cognitive-behavioural-therapy adolescents Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Sleep plays a crucial role in maintaining the health and well-being of adolescents ( 1 ). This period encompasses a transit period from childhood to adulthood that now occupies a greater portion of the life course, spanning the ages of 10 to 24 years old( 2 , 3 ). Several development and maturation changes regarding the neurobiological, hormonal, psychosocial, and physical processes are presented during this period ( 4 , 5 ), which is particularly concerning given the high prevalence of sleep problems and sleep deprivation across adolescents globally ( 5 ). Poor sleep during adolescence is associated with poor decision-making, poor memory, high risk-taking, mood disruptions, and lower academic performance( 1 , 6 ). Furthermore, inadequate or disturbed sleep in adolescents is a risk factor for anxiety( 7 ), depression( 8 ), suicidal ideation( 9 ), cardiovascular disease( 10 ), obesity ( 11 ), and type 2 diabetes( 12 ). Evidence shows that adolescents need more sleep than adults for optimal functioning ( 6 ). The American Sleep Foundation recommends that children aged 10 to 13 should sleep between 9 and 11 hours per night; teens aged 14 to 17 years should aim for 8 to 10 hours, while late adolescents between 18 and 24 years should get 7 to 9 hours of sleep each night ( 13 ). However, society often prioritises academic performance, overlooking the importance of sleep and viewing a lack of sleep as usual. Almost 70% of adolescents (12 to 17 years old) and over 30% of late adolescents (17 to 24 years old) fail to achieve recommended sleep hours( 14 ). Insomnia (e.g., problems initiating or maintaining sleep or struggling to wake up or feeling unrested) or insufficient sleep is highly prevalent among adolescents, with estimates ranging from 4 to 13% ( 15 , 16 ). Sleep duration, sleep quality, and insomnia are modifiable through various behavioural and educational approaches (e.g., sleep hygiene, stimulus control) ( 17 ), as well as lifestyle interventions (e.g., physical activity, diet)( 18 ). Cognitive Behavioural Therapy for insomnia (CBT-I) typically involves a combination of strategies delivered within eight weeks, including psychoeducation, sleep restriction, stimulus control, cognitive therapy, relaxation techniques, and sleep hygiene ( 19 , 20 ). CBT-I is considered a first-line treatment option( 21 , 22 ). Nevertheless, implementation, availability, and utilisation of CBT-I or other behavioural approaches are limited due to cost, expertise availability, convenience, and time constraints ( 23 , 24 ). On the other hand, pharmacological treatment is recommended for short-term use, with potential adverse effects and the risk of dependence and tolerance( 18 ). In adolescents, it is challenging since there is a paucity of approved drugs( 25 ). Behavioural interventions, particularly CBT-I, have been comparable in efficacy to sedative medications in the short term, but have long-term benefits maintained even after the intervention is discontinued ( 23 , 26 ). CBT-I has shown effectiveness and is recommended as the best option for sleep promotion, treatment, or prevention of insomnia ( 24 ), which is also associated with an increase in quality of life ( 27 ). To increase accessibility and availability of sleep behavioural interventions, various digital modalities have been developed, such as e-Health interventions that primarily use the Internet (website), and mHealth interventions that utilise mobile devices such as mobile phones, patient monitoring devices, personal digital assistants, and other wireless devices. Digital CBT-I (dCBT-I), particularly eHealth, is efficacious in adults ( 28 – 31 ). More recent studies have shown its potential efficacy in adolescents ( 32 , 33 ). These findings emphasise the positive effect of dCBT-i in adolescents, who may be reluctant to receive psychotherapy and are more engaged with DHIs than other age groups( 34 ). Therefore, we aim to assess the level of evidence and identify active components of DHIs in sleep promotion, treatment, and prevention of insomnia among adolescents by conducting a systematic review and meta-analysis of Randomized controlled trials (RCTs). Method This systematic review was conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement. The protocol is published in the PROSPERO database (Registration ID: CRD42018095268). Search Strategy We searched the following electronic databases for English language articles published between June 1, 2007 (coinciding with the release of the iPhone and, therefore, expansion of mHealth studies) and June 30, 2023: OVID (Medline), CINAHL, Web of Science, SCOPUS, PsychInfo, and Embase. We did an update on May 30, 2024, using the same databases. In addition, we hand-searched reference lists of identified studies and systematic reviews to identify potentially relevant studies. The Search terms and electronic search strategy are presented in Supplementary File 1, Appendix 1. Inclusion and Exclusion Criteria Eligible participants, interventions, comparisons, outcomes, and study designs (PICOS) were identified a priori and are outlined below. Studies involving adolescents aged 10 to 24 ( 3 , 35 )from general and clinical populations. Individuals with insomnia and coexisting mental health conditions, such as depression and anxiety, were included due to their strong link to cognitive and emotional processes, which is often a therapeutic component. Eligible interventions were RCTs for promoting sleep, treating and preventing insomnia through behavioural interventions (e.g., CBT-I, hygiene sleep, lifestyle), reporting intervention effectiveness as a quantitative outcome, and delivered using eHealth or mHealth approaches. Studies were excluded if they included interventions where eHealth or mHealth functions were not the primary component. Human-based coaching via telephone or interventions via social networks (e.g., Twitter or Facebook) were ineligible. Participants with coexisting physical health conditions (e.g., headaches or pain) were excluded due to the complexity that necessitates a more interdisciplinary approach, making it difficult to isolate the effects of CBT-I or other behavioural interventions. Study Selection Bibliographic records were extracted and imported into Covidence ( https://www.covidence.org/ ). After excluding duplicates, titles, and abstracts were independently assessed by two researchers (AS-S and KK). Additionally, a researcher (AF) independently and randomly reviewed three full texts of relevant articles and extracted them to ensure compliance with the inclusion and exclusion criteria. Data Extraction Two independent researchers (AS-S, KK) prepared a pre-piloted data extraction form using Microsoft Excel and Covidence. An author (AS-S) checked all data extraction for accuracy. Disagreements were resolved by consensus between researchers (AF, KK, AS-S). The data extraction format is presented in Supplementary File 1, Appendix 2. Quality assessment Risk of bias To assess the risk of bias, the quality assessment tool ‘QUALSYST ‘was applied( 36 ). Ten items were evaluated. Research questions and objectives, study design, subject (and comparison group) characteristics, definitions of outcomes, sample size, analytic methods, and results reports for each included study. Reviewers assigned a score of 2 for fulfilling, 1 for partially fulfilling, and 0 for not fulfilling a criterion. Score calibration was achieved through discussion. Hence, a study could receive a maximum score of 20. A complete checklist can be found in supplementary file 1, appendix 3. Two independent reviewers (AS-S and NP) conducted the assessment using the checklist, and the final quality score was ascertained by comparing each of their scores. Discrepancies in scores were reassessed jointly before a consensus was reached. The results of the assessments were considered during data synthesis but did not result in exclusion from this review. Data Analysis and Synthesis The information extracted from the individual reviews was summarised narratively and categorised accordingly. The identified active components were defined based on previous studies and standard protocols for behavioural sleep interventions, particularly CBT-I( 20 , 37 ) The identified behavioural component was made based on the information in the papers (See definitions in Table 1 ). Table 1 Components and delivery formats that are included in the interventions Components Study Interventions N= (%)/Trials N= Authors Education Sleep hygiene education (SH) : General explanation about sleep (e.g., sleep biology, characteristics of healthy sleep, and changes in sleep patterns with aging). n = 9 (100%) /n = 6 de Bruin (2015, 2018, 2020); Freeman (2017); Chan (2022); Morris (2015); Freeman (2017); Werner-Seidler (2023); Li (2023); Champion (2023) Sleep diary (SD) : Self-monitoring of important daily sleep-related information using a sleep diary. n = 5 (55.5%) /n = 3 Chan (2020), de Bruin (2015, 2018, 2020), Freeman (2017) Psychoeducation (PE) : General recommendations to improve sleep, such as lifestyle (e.g., diet, exercise, and substance use) and environmental factors (e.g., light, noise, and temperature) are needed. This may include some elements of other components, such as stimulus control, but these should not be the predominant part of the intervention. n = 9(100%) /n = 6 de Bruin (2015, 2018, 2020); Freeman (2017); Chan (2022); Morris (2015); Freeman (2017); Werner-Seidler (2023); Li (2023) Cognitive Cognitive restructuring (CR) : Skills to identify, challenge, and change unhelpful beliefs about sleep that may disturb sleep. Sometimes, it is called cognitive therapy. This may include behavioural experiments. n = 7 (77.7%) /n = 4 Werner-Seidler (2023), Li (2023), Chan (2022), Freeman (2017), de Bruin (2015,2028,2020) Constructive worry (CW) : Skills to overcome worry in bed by writing down the worries and their solutions before bed. n = 6 (33.3%) /n = 3 Chan (2022), Werner-Seidler (2023), Li (2023), de Bruin (2015,2018,2020) Third-wave components (TW) : Skills to overcome worry in bed by writing down the worries and their solutions before bed. n = 3 (33.3%) /n = 3 de Bruin (2020); Chan (2022); Freeman (2017) Paradoxical intention (PI) : Exercise to remain awake as long as possible after getting into bed. n = 1 (11.1%) /n = 1 Freeman (2017) Guided Imagery (GI) : A Relaxation technique that uses visualization and mental imagery to promote relaxation and calm, ultimately aiding in falling asleep and improving sleep quality. n = 2 (22.2%) /n = 2 Morris, 2015; Freeman (2017 Behavioural Sleep restriction (SR) : Skills to improve sleep by limiting time in bed. First, time in bed is restricted to the average sleep duration plus 30 minutes, and then it is increased or decreased depending on sleep efficiency. n = 6 (66.6%) /n = 4 Chan (2022), Freeman (2017), de Bruin (2015,2028,2020), Morris (2015), Stimulus control (SC) : Skills to reassociate the bed with sleep. Patients are instructed to wake up at the same time every morning, refrain from daytime napping, go to bed only when sleepy, get out of bed when unable to sleep, and use the bed and bedroom for sleep and sex only. n = 8 (88.8%) /n = 5 de Bruin (2015, 2018, 2020); Freeman (2017); Chan (2022); Morris (2015); Werner-Seidler (2023); Li (2023) Relaxation (RT) : involves structured exercises to reduce somatic tension (e.g., abdominal breathing, progressive muscle relaxation, autogenic training) and cognitive arousal (e.g., guided imagery training). n = 6 (66.6%) /n = 4 Chan (2022), Freeman (2017), de Bruin (2015,2018,2020), Morris (2015) Delivery Online therapeutic guidance : Individual interaction with therapists, whether in person or remotely. n = 3 (33.3%)/ n = 1 de Bruin (2015,2028,2020) Human Encouragement : Human beings provide reminders to proceed with the remote self-help treatment program via telephone or email. This should not contain any support related to the therapeutic content. Peer support, such as online discussion groups, was considered part of this component. n = 1 (11.1%)/ n = 1 Champion (2023) (optional) Unguided with automatic messages : Automated reminders to proceed with the treatment program. This should not contain any support related to the therapeutic contents. n = 4 (44.4%)/ n = 3 Freeman (2017), Morris (2015), Werner-Seidler (2023), Li (2023), Unguided : The intervention is delivered without any human or automatic message. n = 1 (11.1%)/n = 1 Chan, 2022 Source: Definitions based on Fukuyama (2024); Walker et al (2022) Finally, the effectiveness of the interventions in the respective studies was evaluated using the R package. The available results that measured Sleep Quality (SQ) using standardised questionnaires after treatment or at follow-up were pooled to identify the short and long-term effects of subjective SQ (the primary outcome). The meta-analysis was performed when results were available for at least two studies. Results Figure 1 illustrates the study selection process. After screening titles and abstracts, nine full-text articles were reviewed ( 38 – 46 ), and five RCTs met the inclusion criteria for the meta-analysis ( 38 , 39 , 41 , 43 , 45 ). For studies using the same sample, the most recent with complete outcome reporting was included ( 41 , 45 ). One study was excluded from the meta-analysis as it lacked a validated sleep quality measure, and the intervention differed from CBT-I ( 46 ) Study quality assessment The median score, as assessed using the QUALsyst tool, was 18 out of 20. The lowest score was 18 ( 38 , 41 ). The highest score was 20 ( 39 , 43 , 45 , 46 ). Among all the checklist items for assessing the quality of quantitative studies, Item 1, ‘Question or objective sufficiently described?’ and Item 11, ' Conclusions supported by the results?’ were most frequently reported. Criteria assessed for Item 9, ‘Controlled for confounding?’, were often not fully met. Scores for each study can be found in Appendix 4. Due to limited studies, sensitivity and moderator analyses, and random-effects component network meta-analysis were not conducted. Summary of the evidence Characteristics of the studies Nine studies on mHealth and eHealth interventions aimed at improving sleep duration and quality among adolescents were included in this systematic review (details in Table 3 ). These studies involved 9,238 participants aged 12 to 24 years (Mean age: 15.6), with 50.3% male, 47.8% female, and 1.9% identifying as other (e.g., non-binary). Sleep was assessed using actigraphy (n = 3) ( 40 – 42 ) and/or questionnaires (n = 8)( 38 – 45 ), including the Insomnia Severity Index (ISI)( 39 , 43 – 45 ), Pittsburgh Sleep Quality Index (PSQI) ( 39 , 43 – 45 ), Sleep Condition Indicator 8-item version (SCI-8) ( 39 ), and Holland Sleep Disorder Questionnaire (HSDQ) ( 40 – 42 ). One study measured daily mean sleep and intention to sleep without a validated tool( 46 ). Intervention durations ranged from six to ten weeks (Median: 6 weeks). The RCTs were conducted in Australia ( 44 – 46 ), Hong Kong( 43 ), the Netherlands ( 40 – 42 ), and the UK ( 38 , 39 ). One study focused on sleep promotion within a broader lifestyle intervention( 46 ), while the remaining eight used dCBT-I. Among these, dCBT-I was applied to assess its efficacy ( 40 ), adding body scan mindfulness ( 42 ), or comparing modalities (email vs face-to-face)( 43 ). Also, dCBT-I was used to reduce paranoia and hallucinations( 39 ), improve psychopathology( 41 ), depression ( 45 )and address rumination in adolescents with depression( 44 ). One study used dCBT for anxiety and insomnia, and the CBT-I component of that intervention was considered for this review( 38 ). Table 3 Effectiveness of digital health interventions for Sleep in adolescents Author Effect on Sleep pre-post and follow-up intervention Effect on psychopathology pre-post and follow-up intervention de Bruin (2015, 2018) Actigraphy SE, SOL, and TST revealed significant small to large effect sizes ( d = 0.30–1.09), with the strongest effect size detected for SE ( d = 1.09). Effects of improved SE and reduced SOL were maintained ( d = 1.10–1.30) at two-month follow-up. WASO nor TIB reached statistical significance as measured by actigraphy at either point ( d = 0.11–0.29). Self-reported sleep diary data, SE and SOL demonstrated significant effects of the intervention at post-intervention relative to the control group ( d = 0.56–0.82), which were maintained at follow-up ( d = 0.52–0.77). The strongest effect was for SE ( d = 0.56). Self-report SQ demonstrated a significant effect at both post and follow-up ( d = 0.41–0.56). Self-report WASO, TIB, and TST did not reach statistical significance at either of the time points ( d = 0.17–0.61). There were no statistical differences between the effects of the dCBT-i program relative to the group-based CBT-I program at post-test or follow-up. Psychopathology outcomes at the 12-month follow-up for dCBT-i and the group-based CBT-I were, respectively: affective ( d = 0.87 and 0.97), anxiety ( d = 0.81 for dCBT-i), somatic ( d = 0.38 and d = 0.52), oppositional ( d = 0.42 for group-based CBT-I) and attention deficit hyperactivity disorder (ADHD) problems ( d = 0.47 and 0.46). de Bruin (2020) Sleep improvements after treatment and follow-up for WASO and SE from actigraphy ( ß = − 0.38, p < .01, ß = − 0.33, p < .05 for WASO, and ß = 0.37, p < .01, ß = 0.31, p < .05 for SE, respectively in the Body Scan group compared to the Non-body Scan group. Baseline to post-treatment for the subscales of shortness of sleep and irritation and the total score from the CSRQ ( ß = −0.50, p < .05, ß = − 0.53, p < .001, ß = − 0.49, p < .05, respectively). Chan (2022) Both groups, GT and ESH, showed a significant reduction in the ISI score after treatment compared with the WL group (GT vs WL: Cohen’s d = -1.03; p < .001; ESH vs WL: d =-0.63; p = .03). Likewise, both treatment groups had more significant overall clinical improvement (GT: d =-1.54; p < .001; ESH: d = -0.76; p = .03) in relative to the WL group after treatment. For sleep diary measures, the GT group had shorter SOL ( d =-0.50; p = .01) and higher SE ( d = 0.50; p = .01) than the WL group after treatment. The GT group also improved sleep quality after the intervention (GT vs WL: d =- 1.04; p. <001) Depression in the GT group shows a significant reduction using the HRSD ( d =-1.0, p < .001) but not in the ESH group ( p = .08) compared with the WL group. Freeman (2017) After treatment, 454 (62%) of 733 individuals in the treatment group and 326 (29%) of 1142 in the control group scored outside the clinical cutoff for insomnia used for trial entry. Compared with usual practice, the sleep intervention at 10 weeks reduced insomnia (adjusted difference 4·78, 95% CI 4·29 to 5·26, Cohen’s d = 1·11; p < 0·0001). Compared with usual practice the dCBT-I decreases paranoia (–2·22, –2·98 to − 1·45, Cohen’s d = 0·19; p < 0·0001), and hallucinations (–1·58, − 1·98 to − 1·18, Cohen’s d = 0·24; p < 0·0001). The mediation analyses indicated a change in sleep over three weeks, which explained 30% of the intervention effect on paranoia at ten weeks, with a change in sleep over ten weeks accounting for 58% of the treatment effect on paranoia. Morris (2015) Medium effect size for self-reported SQ as measured on the PSQI ( d = 0.51). Depression and anxiety did not show significant post-treatment effects ( d = 0.49–0.51) Li (2023) Reductions in rumination did not differ between the intervention and control groups at postintervention, indicating dCBT-I had no significant effect on rumination. In contrast, there was a significantly greater reduction in unhelpful beliefs about sleep in the intervention group relative to the control group at post-intervention, 95% CI = 0.09–3.66, d = 1.24. Thus, neither rumination nor unhelpful beliefs about sleep emerged as significant mediators. However, the within-subject mediation analysis found rumination (Effect = 0.56, 95% CI = 0.06–1.32), but not unhelpful beliefs about sleep, emerged as a significant mediator. This indicates that baseline-to-post-intervention reductions in rumination were associated with a baseline-to-post-intervention reduction in depression symptoms in the intervention group Werner-Seidler et al. (2023) Insomnia was a greater reduction in higher adheres compared to control group participants [t (189.1) = -2.62, p = .010, d = .50] and at follow-up [t (168.4) = -3.22, p = .001, d = .67]. Effect sizes were 0.50 (95% CI 0.15 to 0.85) post-intervention and 0.67 (95% CI 0.29 to 1.04) at follow-up. No reductions were found in the low-adherences and control group (PS > .05); effect sizes were 0.32 (95% CI -0.03 to 0.68) at post-intervention and 0.10 (95% CI -0.28 to 0.47) at follow-up Depression symptoms, with high adherers showing more significant reductions from baseline at post [t (181.5) = _2.95, p = .00, d = .46, 95% CI 0.11 to 0.80] and follow-up [t (160.6) = -2.48, p = .01, d = .48, 95% CI 0.11 to 0.85] compared to the control group. The effect sizes from this trial were in the small to medium range ( d = .27–.41) Champion (2023) There was little evidence of an intervention effect on mean daily hours of sleep between the groups (post-treatment = 0.997 (0.95 to 1.02), 12-month follow-up = 0.91(0.75 to 1.12), and 24-month follow-up = 0.91(0.72 to 1.14). The students (n = 1960; 62.1%) who received sufficient doses had significantly greater mean knowledge of the Big 6 scores over 24 months relative to students in the control group and at each follow-up occasion (post-treatment = 1.85 (1.53 to 2.16) 12-month follow-up = 0.97(0.69 to 1.26), and 24-month follow-up = 0.91(0.62 to 1.21). SE = Sleep Efficiency; Sleep Onset Latency (SOL); Total Sleep Time (TST), Wakefulness After Sleep Onset (WASO) nor Time in Bed (TIB), Sleep Quality (SQ), attention deficit hyperactivity disorder (ADHD), Chronic Sleep Reduction Questionnaire (CSRQ); digital cognitive behavioural therapy for Insomnia (dCBT-I); the Insomnia Severity Index (ISI); Group Therapy (GT) and email-delivered self-help (ESH); WL = Waiting group; Hamilton Rating Scale for Depression (HRSD); Pittsburgh Sleep Quality Index (PSQI) Intervention characteristics Table 2 outlines the intervention modality, duration, support level, behavioural components, completion rates, and follow-up details for each study. Three studies used the same dCBT-I, a website intervention (eHealth), adapted from an adult programme for adolescents( 40 – 42 ). One study adapted a sleep improvement programme for university students (" REFRESH ") to be delivered via email( 43 ). Another used the ‘ Sleepio’ dCBT-I programme, combining website and mobile app delivery (e/mHealth)( 39 ). One intervention, " Insomnia Relief ," was delivered via website with text and email support (eHealth)( 38 ). Two studies used the same chatbot app, " The Sleep Ninja " (mHealth)( 44 , 45 ). A study focused on sleep promotion, through a holistic lifestyle, involved a school-based intervention, " Health4life " (e/mHealth), combining a cartoon-based website and education modules with a companion app encourage behaviour tracking( 46 ). Active Components and Delivery Formats of DHIs for Sleep Tables 1 and 2 outlines the active components per study. Regarding educational components, Sleep Hygiene (SH) and Psychoeducation (PE) were included in all studies (n = 9, 100%). However, different PE topics were delivered; for example, a study provides additional information about circadian components (e.g., morning light exposure) ( 43 ) or the process of sleep ( 39 – 42 ); or general information about a healthy lifestyle ( 46 ). The Sleep Diary (SD) was mentioned in 5 studies (55.5%) ( 39 – 43 ). Concerning cognitive components, the cognitive restructuring (CR) technique was mentioned in most studies (n = 7; 77.7%) ( 39 – 45 ), followed by Constructive Worry (CW) in six studies (66.6%), and third-wave therapy (TW) (mindfulness) was included in 3 studies (33.3%) ( 39 , 42 , 43 ). A study described in detail and tested the additional TW component, which incorporated a 20-minute auditory of ‘body scan meditation’ from a licensed Mindfulness-based Stress Reduction (MBSR)/ Mindfulness-based Cognitive Therapy (MBCT) therapist and was introduced in session two. In sessions three to six, the body scan meditation was reviewed, and further explanation of its possible effects on stress, arousal, and relaxation, and how these relate to sleep problems was provided ( 42 ). Finally, one study included the paradoxical intention (PI) component ( 39 ). Concerning behavioural components, Stimulus Control (SC) was mentioned in most of the studies (n = 8; 88.8%) ( 38 – 45 ), followed by Sleep Restriction (SR) and Relaxation (RT), using particularly progressive muscle relaxation (n = 6; 66%)( 38 – 43 ). Also, two studies (22.2%) used Guided Imagery (GI)( 38 , 39 ). In terms of delivery formats, most interventions were delivered using automatic messages (n = 4, 44.4%) ( 38 , 39 , 44 , 45 ). A study used online therapeutic guidance (weekly online sessions with a sleep expert)( 40 – 42 ). Another study included an optional human encouragement (online and teacher-delivered activities to reinforce the key message and encouragement discussion)( 46 ). Finally, a study did not incorporate any technical or human delivery, making the intervention completely unguided ( 43 ). The components and delivery format used in the trials are presented in Fig. 2 . Intervention effects Table 3 outlines the effects of the interventions. Five dCBT-I trials demonstrated significant effects, ranging from small to large, including objective and subjective measures on sleep outcomes ( d = 0.17–1.30), compared to the control condition on primary sleep outcomes post-intervention ( 38 , 39 , 41 , 43 , 45 ). The dCBT-I exhibited a medium positive effect (n = 5; g = 0.58, p = 0.01) on subjective SQ immediately after treatment when comparing the control groups. In the case of the Health4life intervention ( 46 ) there was little evidence of an intervention effect on mean daily hours of sleep between the groups (post-treatment = 0.997 (0.95 to 1.02), 12-month follow-up = 0.91(0.75 to 1.12), and 24-month follow-up = 0.91 (0.72 to 1.14). Also, the dCBT-I improved psychopathology in the population and showed small and medium effects, including effects on depression ( d = 0.49–1.0)( 32 ), anxiety, ADHD ( d = 0.47 − 0.46)( 41 ), paranoia ( d = 0.19), and hallucinations ( d = 0.24)( 39 ). Meta-Analysis: Short and long-term Sleep Quality (SQ) The pooled effect sizes after the treatment and at the follow-up subjective SQ were calculated to identify the short- and long-term effects of dCBT-I. Three studies conducted follow-up evaluations, specifically at weeks 14 and 22 from treatment initiation (equivalent to three months after the posttreatment evaluation)( 39 ) and two months after treatment completion( 45 ). One study performed follow-ups at 2, 6, and 12 months after treatment ( 41 ) the results of the two-month follow-up were included to match the other studies' time points and calculate the pooled effect size for long-term effects. Chan, Lam ( 43 ) was excluded from the analysis because follow-up data on the waiting group were not reported. Scores on the PSQI, ISI and HSDQi after treatment or at the follow-up evaluation were employed as the primary sleep outcomes for meta-analysis. The effect size for subjective SQ was significant for the posttreatment evaluation (n = 5; g = − 0.64 [95% CI = − 1.02, − 0.25]) but not for the follow-up evaluation (n = 3; g = 0.54 [95% CI = − 1.02, 0.25], in which only three studies provided follow-up measures with the control group (Fig. 2 ). High heterogeneity in the subjective SQ after treatment and at the follow-up was also noted (Fig. 3 , 4 , 5 ). Discussion This review summarises the evidence of active components of DHIs for sleep promotion, treatment, and prevention of insomnia among adolescents and examines their effectiveness. In terms of educational components, all interventions included HS and PE, while three dCBT-I trials included SD. Even though education alone is not sufficient to ensure effectiveness in treating insomnia ( 37 ), it remains a recommended component of the CBT-I package( 20 ). In particular, SD has demonstrated validity, clinical utility, and usability for providing feedback for SQ to individuals ( 47 ). As a result, SD may have an additional effect as an active component in sleep interventions in combination with HS and PE. The three trials in this review using SD showed moderate effects on SQ after intervention and follow-up ( 39 , 41 , 43 ). Hence, future sleep interventions should consider SD to enhance effectiveness. In terms of cognitive components, CR was utilised in most studies (n = 7, 77%). CR aims to modify maladaptive thought patterns contributing to insomnia ( 20 ). This approach is consistent with transdiagnostic models, which posit that changes in cognitive patterns can positively impact a range of common mental health conditions ( 48 ). For example, in this review, Morris et al ( 38 ) demonstrated that CBT-I could also mitigate symptoms of anxiety. Similarly, this review identified comparable effects on depressive symptoms ( 39 , 43 – 45 ), underscoring the potential transdiagnostic applications of CBT-I. Additionally, CW emerged as a significant component, appearing in six studies (66.6%), thus emphasising the relevance of rumination in sleep interventions. Despite the established role of rumination as a critical mechanism of change in both depression and insomnia, only one study conducted a mediation analysis to explore its impact ( 44 ). The authors revealed that addressing rumination as a mediating variable can enhance the effectiveness of sleep interventions for youth with comorbid psychopathology. Consequently, CR and CW should be integrated into CBT-I protocols and other behavioural sleep interventions, given their status as a maintenance variable and a transdiagnostic process implicated in various mental disorders, including insomnia ( 49 , 50 ). The TW components, particularly mindfulness, were used in 3 studies (33.3%). TW has indicated an additional effect of CBT-I in adult interventions( 37 ). In this review de Bruin, Meijer ( 42 ) study showed that using a body scan meditation (BSM) in CBT-I may have an additional positive effect on sleep, above and beyond the impact of the traditional CBT-I techniques in adolescents. Studies have suggested that the differences are due to adolescents having higher levels of sleep motor activity than adults ( 51 ). Therefore, BSM might have an extra effect on the intervention, affecting both the physical arousal caused by worry and the worry itself by affecting the process that ties these two together. Thus, TW and particularly BSM can benefit adolescents by decreasing physiological arousal and prolonging calm respiration awareness. Therefore, TW should be considered in future adolescent protocol interventions for sleep. It is important to note that none of the studies included acceptance and commitment therapy as part of TW, which has been effective in treating insomnia in adults ( 37 ); an approach that requires further exploration for this age group in digital sleep interventions. Only one study included the Paradoxical intention (PI) component ( 39 ), considered an evidence-based single component for insomnia that has the potential to reduce sleep onset latency (SOL), the number of awakenings, and sleep performance anxiety ( 52 ). The intervention Sleepio by Freeman, Sheaves ( 39 ) showed moderate-sized effects in reducing insomnia symptoms, comparable to other studies in this review without the PI component. This component may have potential effects on comorbid mental health conditions, such as anxiety and depression, helping to distract from worry and rumination, and is a recommended component to incorporate as part of the dCBT-I package ( 52 ). Due to the lack of studies on dCBT-I in adolescents, we cannot assume that PI does not play a significant role. Regarding behavioural components, the SC was part of all CBT-I studies. CS is considered a standalone treatment for insomnia and the most widely used component ( 53 ). However, the mechanism of action in SC is poorly understood due to the several variations of the instructions in the literature ( 53 ). The studies in this review did not mention implementation details, which suggests that they varied between the trials. However, SC is effective in reducing insomnia symptoms compared with control groups in adults ( 53 )and could be used as the sole behavioural intervention when adherence to SR or other CBT-I components is a significant challenge for the clients( 21 ), making SC a critical active component. Concerning SR, it was used in most of the CBT-I trials (n = 4, 44.4%) in this review. SR is often claimed to be the most effective standalone intervention in the treatment of insomnia ( 54 ). In this review, one dCBT-I trial, the Sleep Ninja App did not include SR ( 45 ), a decision made after parent consultation and adolescents, given the program's unguided format and the participants' age. Also, the program was delivered with a briefer CBT-I (1 hour) compared with the traditional face-to-face (6 hours) and other digital interventions, such as Sleepio (3-6hs). However, the Sleep Ninja App showed moderate effects in reducing insomnia symptoms relative to the control group, which can suggest that the SR component in fully automatic DHIs in early adolescents can be omitted, specifically when it is not targeting participants with chronic insomnia. Related to relaxation therapies (RT), Guided Imagery (GI) was used in 2 studies (22.2%) ( 38 , 39 ). GI has been recommended as a combination of mind/body techniques that appear to work synergistically( 55 ). The same studies accompanied progressive muscle relaxation in combination with GI and demonstrated decreased physiological activation, contributing to adolescent relaxation. Two trials have a sole progressive muscle relaxation component ( 41 , 43 ), assessed as part of the CBT-I package; it is unclear whether this component alone has a different effect. However, the literature has shown that muscle relaxation is efficacious alongside other CBT-I packages but not as a standalone component ( 56 ). In this review, the Ninja App intervention did not include any relaxation therapy component ( 45 ) and showed a medium effect size in reducing insomnia symptoms. Since this is an unguided programme, the RT component may be considered an optional approach when implemented as part of the dCBT-I package. Among the studies, most were delivered unguided with automatic messages (n = 4; 44.4%), indicating the potential scalability of DHI for sleep. It is noted that only one trial included a guided intervention with an expert; the intervention was delivered to adolescents with an insomnia diagnosis, which differed from the other trials, which included participants with symptoms of insomnia, making it a support for participants with severe symptoms, also recommended in DHI. Various elements have been considered in digital interventions for sleep, such as how to deliver the treatment (e.g., email, website, mobile App) and the appropriate level of support (e.g., reminders, synchronous, asynchronous messages, human support)( 57 ). Interestingly, most studies do not include human support in this review, providing evidence of the potential scalability of these interventions within the population to prevent and treat insomnia. For example, in this review, Chan, Lam ( 43 ) delivered the intervention by email with no synchronic, asynchrony, or human support. Also, the Sleep Ninja programme was delivered fully automatically using a chatbot. Each module lasted 5–10 minutes and was spaced sequentially over a minimum of 3 weeks (1 hour). Compared to other dCBT-I or traditional face-to-face CBT-I packages that require a minimum of 6 hours ( 40 )(de Bruin et al., 2014), that intervention was the briefest. The authors showed that the small bites of therapeutic content for behavioural change were sufficient, considering the medium effect size shown in the intervention. The results may suggest that this approach can be scaled up for the general population, promoting sleep in the public health domain. Effectiveness Our findings indicate that dCBT-I effectively treats adolescent insomnia. One study examined sleep promotion within a holistic lifestyle intervention, but did not find a significant impact on behavioural change ( 46 ). dCBT-i exhibited a medium positive effect on subjective SQ immediately after treatment compared to control groups, though no significant treatment effect of dCBT-i at the follow-up was discovered. Further, no significant improvements in objective SQ (i.e., SE) were noted (Only one trial reported actigraphy( 41 )). Interestingly, the effect size was of higher magnitude for participants with clinically significant insomnia, regarding short-term and long-term efficacy, compared to the control intervention. Finally, psychopathology improved with the dCBT-i exhibited small to medium positive outcomes compared to control groups. Three trials in this review ( 39 , 43 – 45 ), showed a medium effect size, reducing insomnia symptoms and small effects of depression. Similarly, in the case of anxiety, with a small effect in reducing the symptoms and a moderate effect in reducing insomnia symptoms ( 38 ). These findings contribute to emerging evidence of the positive effects of digital sleep interventions and indicate a mechanistic and potentially causal role for insomnia symptoms in depression and anxiety, consistent with studies on adults ( 58 , 59 ). Also, findings in the adolescent population indicate that cognitive processes are crucial in perpetuating or ameliorating adolescent insomnia, but little is known about which facets of insomnia can be affected by interventions that target these processes in adolescents ( 51 ). Due to the high comorbidity between mood disorders and insomnia, it might be possible that the reduction of mood symptoms is partly due to the restoration of good sleep, implying the mediating effect of sleep in the trajectory of mood-related psychopathology. In Sleep Efficiency (SE), Sleep Onset Latency (SOL), and Total Sleep Time (TST), as measured by actigraphy, revealed significant small to large effect sizes ( d = 0.30–1.09), with the strongest effect size detected for SE ( d = 1.09). Effects of improved SE and reduced SOL were maintained at the two-month follow-up ( d = 1.10–1.30)( 41 ). Unfortunately, only one trial in this review has used actigraphy measures to determine adolescent sleep patterns. Future studies should include objective measures like actigraphy to gain a more comprehensive understanding of how the intervention affects sleep in this population. In the case of e/m health-promoting sleep by Campion (2023) ( 46 ), the outcomes did not show significant differences related to sleep. Simultaneous prevention/promotion interventions require more studies, as it is not clear which component affects direct or indirect behaviours, such as sleep ( 60 ). However, the study potentially indicates that adolescents could learn preventive information about the Big 6 lifestyle factors, which may not be transferable to behavioural change. Future RCT studies of adolescent sleep promotion is needed, including components other than psychoeducation and sleep hygiene. Evidence has shown that CBT-I can also prevent insomnia and support other comorbid mental health conditions ( 58 , 59 ). Concerning attrition and drop-out, the dropout rate in the studies was high, particularly in Freeman et al ( 39 ). The dropout from that study assessment was high (50%) during the study and was greater in the treatment group than in the control group. Werner-Seidler et al ( 45 )showed significant differences regarding the effect of sleep and depression on adherence and non-adherence. In the same way, Champion et al.( 46 ) mentioned that the group who received the intended doses showed greater knowledge. Future studies should evaluate high and low adherence and dose, considering the differences in the intervention effect compared to the control group. Furthermore, an additional hint that might enhance adherence among younger adolescents (between 10 and 13 years) is the participation of parents in the intervention due to the crucial role they have in influencing adolescent health behaviours ( 61 ). Only two studies in this review included parents( 40 – 42 , 46 ). A systematic review showed that parent-based interventions with adolescent components were associated with positive program effects( 62 ). Future studies may consider the participation of the parents or caregivers as part of the sleep intervention. The results of this study suggest that including sleep interventions in mental health protocols can enhance the effectiveness of current interventions. Behavioural sleep interventions are often overlooked in these protocols and adding them could potentially improve overall outcomes. The study pointed out the importance of sleep difficulties for mental health in adolescents and the need for reconsideration of clinical services with a priority given to improving sleep. Strengths and Limitations Our review has several strengths. First, we performed a comprehensive and up-to-date systematic review, allowing the inclusion of RCTs of DHIs for sleep. To our knowledge, this is the first review of the active components of DHIs for sleep promotion and insomnia in adolescents. Second, we used evidence-based components to assess the dCBT-I intervention delivery formats. Identifying the components is key to conducting this review. We made and reviewed a table of the definitions of components a priori from previous studies (Table 1 ). Third, our findings showed that DHIs are an effective alternative and scalable intervention for adolescents, who often do not have access to behavioural interventions for sleep problems. The review also shows evidence of active components for sleep interventions (PE, HS, SC, and TW) able to be used didactically and implemented in different groups and contexts with minimal human assistance. Our analytic approach was dichotomously defined components as either present or absent based on the descriptions provided in the studies, which may be considered a limitation because this approach does not consider possible variation in implementation. Furthermore, some components may have overlapping contents, such as PE and HS, even though their procedures and supposed mechanisms of action are distinct enough to be considered and evaluated as different components. Larger trials specifically designed to test the efficacy of various components are needed to determine if specific combinations are more effective than others. In 3 studies, the COVID-19 pandemic may have affected the outcomes of the interventions, increasing, for instance, screen time ( 46 ) and anxiety symptoms ( 44 , 45 ). Throughout the pandemic, adolescents experienced substantial disruptions to schooling, employment, and peer relationships, and effects on health behaviours among youths have been documented worldwide; therefore, those outcomes must be analysed with caution. Most studies did not collect objective data and relied on self-report surveys. Only one trial reported actigraphy data ( 41 ). The studies were developed and conducted in high-income countries and most Western countries. Only one study was conducted in Asia (Hong Kong). Also, middle or upper socioeconomic status and living in major cities in the trials limit the generalisability of the results. Future studies should recruit populations with greater cultural and socioeconomic diversity. Conclusions The studies in this review show that dCBT-I is likely to lead to reductions in overall insomnia and also reductions in other mental health symptoms such as depression and anxiety ( 38 , 41 , 43 – 45 ), even psychotic symptoms (hallucinations) ( 39 ). It might also be possible that mindfulness, relaxation strategies, and cognitive restructuring in the CBT-I treatment contributed to improving mental health-related outcomes. In conclusion, based on the literature review and the outcomes in this review, we recommend including the following active components in the DHIs package for promotion, prevention, or insomnia treatment: SD, mainly as part of education components, along with HD and PE, regarding cognitive components, CR, CW and TW. Regarding behavioural components, SC and optional SR are when the intervention is fully automatic with early adolescents, and RT is an optional component. Declarations Conflict of interest The authors do not have any conflicts of interest to disclose. Funding This review was supported by the Agency for Science, Research and Technology (ASTAR), Institute for Human Development and Potential (IHDP). The views expressed are those of the author(s) and not necessarily those of ASTAR, IHDP. Author Contribution AS-S: Conceptualization; writing the original draft; methodology; writing, reviewing and editing; formal analysis; data curation; validation. AF: Methodology, validation, review, and editing; formal analysis. NP: Meta-analysis and review of study quality. AR and JE: Review and editing; validation. All authors have read and commented on the manuscript. Acknowledgement We wish to express our gratitude to Kiran Kaur for supporting and carrying out the database search References Bruce ES, Lunt L, McDonagh JE. Sleep in adolescents and young adults. Clinical medicine. 2017;17(5):424. 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Supplementary Files Supplementaryfile.docx PRISMA2020checklist.docxsafe.pdf Table2.docx Cite Share Download PDF Status: Published Journal Publication published 04 Dec, 2025 Read the published version in npj Digital Medicine → Version 1 posted Editorial decision: Revision requested 14 Jun, 2025 Reviews received at journal 11 Jun, 2025 Reviewers agreed at journal 09 Jun, 2025 Reviewers agreed at journal 30 May, 2025 Reviews received at journal 29 May, 2025 Reviewers agreed at journal 16 May, 2025 Reviewers invited by journal 15 May, 2025 Editor assigned by journal 15 May, 2025 Submission checks completed at journal 15 May, 2025 First submitted to journal 07 May, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6609677","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Systematic Review","associatedPublications":[],"authors":[{"id":453110834,"identity":"9d3033f0-0886-4d5d-930f-caced1bb0ef9","order_by":0,"name":"Alicia Salamanca Sanabria","email":"data:image/png;base64,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","orcid":"","institution":"Agency for Science, Technology and Research","correspondingAuthor":true,"prefix":"","firstName":"Alicia","middleName":"Salamanca","lastName":"Sanabria","suffix":""},{"id":453110835,"identity":"32ee17c7-af83-48e7-bc67-84d560c4f480","order_by":1,"name":"Anna Fogel","email":"","orcid":"","institution":"Agency for Science, Technology and Research","correspondingAuthor":false,"prefix":"","firstName":"Anna","middleName":"","lastName":"Fogel","suffix":""},{"id":453110836,"identity":"f8886064-a917-4bd3-8778-ab3bada97f95","order_by":2,"name":"Padmapriya Natarajan","email":"","orcid":"","institution":"National University of Singapore","correspondingAuthor":false,"prefix":"","firstName":"Padmapriya","middleName":"","lastName":"Natarajan","suffix":""},{"id":453110837,"identity":"5c8f4544-2444-4398-af93-b8d2718a497a","order_by":3,"name":"Alina Rodriguez","email":"","orcid":"","institution":"Institute for Human Development and Potential (IHDP)","correspondingAuthor":false,"prefix":"","firstName":"Alina","middleName":"","lastName":"Rodriguez","suffix":""},{"id":453110838,"identity":"a93f222a-6565-4c66-b7ec-d339f8d25422","order_by":4,"name":"Eriksson Johan Gunnar","email":"","orcid":"","institution":"Institute for Human Development and Potential (IHDP)","correspondingAuthor":false,"prefix":"","firstName":"Eriksson","middleName":"Johan","lastName":"Gunnar","suffix":""}],"badges":[],"createdAt":"2025-05-07 08:23:11","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6609677/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6609677/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41746-025-02152-6","type":"published","date":"2025-12-04T15:57:21+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":82359043,"identity":"b06a65ae-1c00-4bb9-9b92-0b225972a0dc","added_by":"auto","created_at":"2025-05-09 11:26:42","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":47769,"visible":true,"origin":"","legend":"\u003cp\u003eFlow Diagram\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-6609677/v1/629bd8a835683043b167a545.png"},{"id":82359044,"identity":"d53d7052-290a-4a43-945f-47ba03664d5a","added_by":"auto","created_at":"2025-05-09 11:26:42","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":104412,"visible":true,"origin":"","legend":"\u003cp\u003eInterventions components by category, percentage, and authors\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-6609677/v1/efe317b74c1815b7874b7571.png"},{"id":82359914,"identity":"d7788c1c-2aeb-4089-a5ce-d3bb4c229ff8","added_by":"auto","created_at":"2025-05-09 11:34:42","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":46316,"visible":true,"origin":"","legend":"\u003cp\u003eForest plot for the short of dCBT-i on subjective sleep quality (SQ). Subjective SQ was evaluated using the Pittsburgh Sleep Quality Index (PSQI; Morris et al.,2015), Insomnia Severity Index (ISI; Freeman et al., 2017, Chan, 2022., Werner-Seidler, 2023), or Holland Sleep Disorder Questionnaire-Insomnia (HSDQi; De Bruin et al., 2018).\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-6609677/v1/cb2369cac9afaa5812073bbb.png"},{"id":82359051,"identity":"9e55f36c-8d22-412f-9791-6d1850f3921b","added_by":"auto","created_at":"2025-05-09 11:26:42","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":41279,"visible":true,"origin":"","legend":"\u003cp\u003eForest plot for the long-term effects of dCBT-i on subjective sleep quality (SQ). Subjective SQ was evaluated the Insomnia Severity Index (ISI; Freeman et al., 2017; Werner-Seidler, 2023), or Holland Sleep Disorder Questionnaire-Insomnia (HSDQi; De Bruin et al., 2018).\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-6609677/v1/4ddcacbb5cada3906e0a4761.png"},{"id":82359915,"identity":"60976e61-d1fa-4ecf-959c-c990513e6bdf","added_by":"auto","created_at":"2025-05-09 11:34:42","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":40039,"visible":true,"origin":"","legend":"\u003cp\u003eStandardized mean difference between studies\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-6609677/v1/7567ed6a799b773f55a87109.png"},{"id":97723810,"identity":"ee879e31-372e-4915-98ed-f004d2bd8f3f","added_by":"auto","created_at":"2025-12-08 16:07:23","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1459585,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6609677/v1/8d25cd3c-d312-45d1-b887-a666b0a02bfc.pdf"},{"id":82359050,"identity":"c50a6e6d-a192-475a-bf03-569c54edc7c2","added_by":"auto","created_at":"2025-05-09 11:26:42","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":257916,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementaryfile.docx","url":"https://assets-eu.researchsquare.com/files/rs-6609677/v1/42925cd33a7689dd94d5f00e.docx"},{"id":82361094,"identity":"a14da50b-4a94-4597-9707-d9456afcfb85","added_by":"auto","created_at":"2025-05-09 11:42:43","extension":"pdf","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":119814,"visible":true,"origin":"","legend":"","description":"","filename":"PRISMA2020checklist.docxsafe.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6609677/v1/ca13222817d8189d73b890a4.pdf"},{"id":82359048,"identity":"540bed35-5c0c-4f70-b6a8-89a468dc2fd0","added_by":"auto","created_at":"2025-05-09 11:26:42","extension":"docx","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":24571,"visible":true,"origin":"","legend":"","description":"","filename":"Table2.docx","url":"https://assets-eu.researchsquare.com/files/rs-6609677/v1/5d8ef3e3bcbcfc5d076afb84.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Active Components in Digital Health Interventions for Sleep among Adolescents: A Systematic Review and Meta-Analysis of Randomized Controlled Trials","fulltext":[{"header":"Introduction","content":"\u003cp\u003eSleep plays a crucial role in maintaining the health and well-being of adolescents (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). This period encompasses a transit period from childhood to adulthood that now occupies a greater portion of the life course, spanning the ages of 10 to 24 years old(\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). Several development and maturation changes regarding the neurobiological, hormonal, psychosocial, and physical processes are presented during this period (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e), which is particularly concerning given the high prevalence of sleep problems and sleep deprivation across adolescents globally (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). Poor sleep during adolescence is associated with poor decision-making, poor memory, high risk-taking, mood disruptions, and lower academic performance(\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Furthermore, inadequate or disturbed sleep in adolescents is a risk factor for anxiety(\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e), depression(\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e), suicidal ideation(\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e), cardiovascular disease(\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e), obesity (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e), and type 2 diabetes(\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eEvidence shows that adolescents need more sleep than adults for optimal functioning (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). The American Sleep Foundation recommends that children aged 10 to 13 should sleep between 9 and 11 hours per night; teens aged 14 to 17 years should aim for 8 to 10 hours, while late adolescents between 18 and 24 years should get 7 to 9 hours of sleep each night (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e). However, society often prioritises academic performance, overlooking the importance of sleep and viewing a lack of sleep as usual. Almost 70% of adolescents (12 to 17 years old) and over 30% of late adolescents (17 to 24 years old) fail to achieve recommended sleep hours(\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). Insomnia (e.g., problems initiating or maintaining sleep or struggling to wake up or feeling unrested) or insufficient sleep is highly prevalent among adolescents, with estimates ranging from 4 to 13% (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eSleep duration, sleep quality, and insomnia are modifiable through various behavioural and educational approaches (e.g., sleep hygiene, stimulus control) (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e), as well as lifestyle interventions (e.g., physical activity, diet)(\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). Cognitive Behavioural Therapy for insomnia (CBT-I) typically involves a combination of strategies delivered within eight weeks, including psychoeducation, sleep restriction, stimulus control, cognitive therapy, relaxation techniques, and sleep hygiene (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). CBT-I is considered a first-line treatment option(\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e). Nevertheless, implementation, availability, and utilisation of CBT-I or other behavioural approaches are limited due to cost, expertise availability, convenience, and time constraints (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e). On the other hand, pharmacological treatment is recommended for short-term use, with potential adverse effects and the risk of dependence and tolerance(\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). In adolescents, it is challenging since there is a paucity of approved drugs(\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e). Behavioural interventions, particularly CBT-I, have been comparable in efficacy to sedative medications in the short term, but have long-term benefits maintained even after the intervention is discontinued (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e). CBT-I has shown effectiveness and is recommended as the best option for sleep promotion, treatment, or prevention of insomnia (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e), which is also associated with an increase in quality of life (\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eTo increase accessibility and availability of sleep behavioural interventions, various digital modalities have been developed, such as e-Health interventions that primarily use the Internet (website), and mHealth interventions that utilise mobile devices such as mobile phones, patient monitoring devices, personal digital assistants, and other wireless devices. Digital CBT-I (dCBT-I), particularly eHealth, is efficacious in adults (\u003cspan additionalcitationids=\"CR29 CR30\" citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e). More recent studies have shown its potential efficacy in adolescents (\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e). These findings emphasise the positive effect of dCBT-i in adolescents, who may be reluctant to receive psychotherapy and are more engaged with DHIs than other age groups(\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e). Therefore, we aim to assess the level of evidence and identify active components of DHIs in sleep promotion, treatment, and prevention of insomnia among adolescents by conducting a systematic review and meta-analysis of Randomized controlled trials (RCTs).\u003c/p\u003e"},{"header":"Method","content":"\u003cp\u003eThis systematic review was conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement. The protocol is published in the PROSPERO database (Registration ID: CRD42018095268).\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eSearch Strategy\u003c/h2\u003e \u003cp\u003eWe searched the following electronic databases for English language articles published between June 1, 2007 (coinciding with the release of the iPhone and, therefore, expansion of mHealth studies) and June 30, 2023: OVID (Medline), CINAHL, Web of Science, SCOPUS, PsychInfo, and Embase. We did an update on May 30, 2024, using the same databases. In addition, we hand-searched reference lists of identified studies and systematic reviews to identify potentially relevant studies. The Search terms and electronic search strategy are presented in Supplementary File 1, Appendix 1.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eInclusion and Exclusion Criteria\u003c/h3\u003e\n\u003cp\u003eEligible participants, interventions, comparisons, outcomes, and study designs (PICOS) were identified a priori and are outlined below. Studies involving adolescents aged 10 to 24 (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e)from general and clinical populations. Individuals with insomnia and coexisting mental health conditions, such as depression and anxiety, were included due to their strong link to cognitive and emotional processes, which is often a therapeutic component. Eligible interventions were RCTs for promoting sleep, treating and preventing insomnia through behavioural interventions (e.g., CBT-I, hygiene sleep, lifestyle), reporting intervention effectiveness as a quantitative outcome, and delivered using eHealth or mHealth approaches.\u003c/p\u003e \u003cp\u003eStudies were excluded if they included interventions where eHealth or mHealth functions were not the primary component. Human-based coaching via telephone or interventions via social networks (e.g., Twitter or Facebook) were ineligible. Participants with coexisting physical health conditions (e.g., headaches or pain) were excluded due to the complexity that necessitates a more interdisciplinary approach, making it difficult to isolate the effects of CBT-I or other behavioural interventions.\u003c/p\u003e\n\u003ch3\u003eStudy Selection\u003c/h3\u003e\n\u003cp\u003eBibliographic records were extracted and imported into Covidence (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.covidence.org/\u003c/span\u003e\u003cspan address=\"https://www.covidence.org/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e). After excluding duplicates, titles, and abstracts were independently assessed by two researchers (AS-S and KK). Additionally, a researcher (AF) independently and randomly reviewed three full texts of relevant articles and extracted them to ensure compliance with the inclusion and exclusion criteria.\u003c/p\u003e\n\u003ch3\u003eData Extraction\u003c/h3\u003e\n\u003cp\u003eTwo independent researchers (AS-S, KK) prepared a pre-piloted data extraction form using Microsoft Excel and Covidence. An author (AS-S) checked all data extraction for accuracy. Disagreements were resolved by consensus between researchers (AF, KK, AS-S). The data extraction format is presented in Supplementary File 1, Appendix 2.\u003c/p\u003e\n\u003ch3\u003eQuality assessment Risk of bias\u003c/h3\u003e\n\u003cp\u003eTo assess the risk of bias, the quality assessment tool \u0026lsquo;QUALSYST \u0026lsquo;was applied(\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e). Ten items were evaluated. Research questions and objectives, study design, subject (and comparison group) characteristics, definitions of outcomes, sample size, analytic methods, and results reports for each included study. Reviewers assigned a score of 2 for fulfilling, 1 for partially fulfilling, and 0 for not fulfilling a criterion. Score calibration was achieved through discussion. Hence, a study could receive a maximum score of 20. A complete checklist can be found in supplementary file 1, appendix 3. Two independent reviewers (AS-S and NP) conducted the assessment using the checklist, and the final quality score was ascertained by comparing each of their scores. Discrepancies in scores were reassessed jointly before a consensus was reached. The results of the assessments were considered during data synthesis but did not result in exclusion from this review.\u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eData Analysis and Synthesis\u003c/h2\u003e \u003cp\u003eThe information extracted from the individual reviews was summarised narratively and categorised accordingly. The identified active components were defined based on previous studies and standard protocols for behavioural sleep interventions, particularly CBT-I(\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e) The identified behavioural component was made based on the information in the papers (See definitions in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComponents and delivery formats that are included in the interventions\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eComponents\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eStudy Interventions\u003c/p\u003e \u003cp\u003eN= (%)/Trials N=\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAuthors\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e\u003cb\u003eEducation\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eSleep hygiene education (SH)\u003c/b\u003e: General explanation about sleep (e.g., sleep biology, characteristics of healthy sleep, and changes in sleep patterns with aging).\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;9 (100%) /n\u0026thinsp;=\u0026thinsp;6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ede Bruin (2015, 2018, 2020); Freeman (2017); Chan (2022); Morris (2015); Freeman (2017); Werner-Seidler (2023); Li (2023); Champion (2023)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eSleep diary (SD)\u003c/b\u003e: Self-monitoring of important daily sleep-related information using a sleep diary.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;5 (55.5%) /n\u0026thinsp;=\u0026thinsp;3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eChan (2020), de Bruin (2015, 2018, 2020), Freeman (2017)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003ePsychoeducation (PE)\u003c/b\u003e: General recommendations to improve sleep, such as lifestyle (e.g., diet, exercise, and substance use) and environmental factors (e.g., light, noise, and temperature) are needed. This may include some elements of other components, such as stimulus control, but these should not be the predominant part of the intervention.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;9(100%) /n\u0026thinsp;=\u0026thinsp;6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ede Bruin (2015, 2018, 2020); Freeman (2017); Chan (2022); Morris (2015); Freeman (2017); Werner-Seidler (2023); Li (2023)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"4\" rowspan=\"5\"\u003e \u003cp\u003e\u003cb\u003eCognitive\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eCognitive restructuring (CR)\u003c/b\u003e: Skills to identify, challenge, and change unhelpful beliefs about sleep that may disturb sleep. Sometimes, it is called cognitive therapy. This may include behavioural experiments.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;7 (77.7%) /n\u0026thinsp;=\u0026thinsp;4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eWerner-Seidler (2023), Li (2023), Chan (2022), Freeman (2017), de Bruin (2015,2028,2020)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eConstructive worry (CW)\u003c/b\u003e: Skills to overcome worry in bed by writing down the worries and their solutions before bed.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;6 (33.3%) /n\u0026thinsp;=\u0026thinsp;3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eChan (2022), Werner-Seidler (2023), Li (2023), de Bruin (2015,2018,2020)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eThird-wave components (TW)\u003c/b\u003e: Skills to overcome worry in bed by writing down the worries and their solutions before bed.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;3 (33.3%) /n\u0026thinsp;=\u0026thinsp;3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ede Bruin (2020); Chan (2022); Freeman (2017)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eParadoxical intention (PI)\u003c/b\u003e: Exercise to remain awake as long as possible after getting into bed.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;1 (11.1%) /n\u0026thinsp;=\u0026thinsp;1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eFreeman (2017)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eGuided Imagery (GI)\u003c/b\u003e: A Relaxation technique that uses visualization and mental imagery to promote relaxation and calm, ultimately aiding in falling asleep and improving sleep quality.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;2 (22.2%) /n\u0026thinsp;=\u0026thinsp;2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMorris, 2015; Freeman (2017\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e\u003cb\u003eBehavioural\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eSleep restriction (SR)\u003c/b\u003e: Skills to improve sleep by limiting time in bed. First, time in bed is restricted to the average sleep duration plus 30 minutes, and then it is increased or decreased depending on sleep efficiency.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;6 (66.6%) /n\u0026thinsp;=\u0026thinsp;4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eChan (2022), Freeman (2017), de Bruin (2015,2028,2020), Morris (2015),\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eStimulus control (SC)\u003c/b\u003e: Skills to reassociate the bed with sleep. Patients are instructed to wake up at the same time every morning, refrain from daytime napping, go to bed only when sleepy, get out of bed when unable to sleep, and use the bed and bedroom for sleep and sex only.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;8 (88.8%) /n\u0026thinsp;=\u0026thinsp;5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ede Bruin (2015, 2018, 2020); Freeman (2017); Chan (2022); Morris (2015); Werner-Seidler (2023); Li (2023)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eRelaxation (RT)\u003c/b\u003e: involves structured exercises to reduce somatic tension (e.g., abdominal breathing, progressive muscle relaxation, autogenic training) and cognitive arousal (e.g., guided imagery training).\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;6 (66.6%) /n\u0026thinsp;=\u0026thinsp;4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eChan (2022), Freeman (2017), de Bruin (2015,2018,2020), Morris (2015)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"3\" rowspan=\"4\"\u003e \u003cp\u003e\u003cb\u003eDelivery\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eOnline therapeutic guidance\u003c/b\u003e: Individual interaction with therapists, whether in person or remotely.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;3 (33.3%)/ n\u0026thinsp;=\u0026thinsp;1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ede Bruin (2015,2028,2020)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eHuman Encouragement\u003c/b\u003e: Human beings provide reminders to proceed with the remote self-help treatment program via telephone or email. This should not contain any support related to the therapeutic content. Peer support, such as online discussion groups, was considered part of this component.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;1 (11.1%)/ n\u0026thinsp;=\u0026thinsp;1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eChampion (2023) (optional)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eUnguided with automatic messages\u003c/b\u003e: Automated reminders to proceed with the treatment program. This should not contain any support related to the therapeutic contents.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;4 (44.4%)/ n\u0026thinsp;=\u0026thinsp;3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eFreeman (2017), Morris (2015), Werner-Seidler (2023), Li (2023),\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eUnguided\u003c/b\u003e: The intervention is delivered without any human or automatic message.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;1 (11.1%)/n\u0026thinsp;=\u0026thinsp;1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eChan, 2022\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eSource: Definitions based on Fukuyama (2024); Walker et al (2022)\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eFinally, the effectiveness of the interventions in the respective studies was evaluated using the R package. The available results that measured Sleep Quality (SQ) using standardised questionnaires after treatment or at follow-up were pooled to identify the short and long-term effects of subjective SQ (the primary outcome). The meta-analysis was performed when results were available for at least two studies.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eFigure \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e illustrates the study selection process. After screening titles and abstracts, nine full-text articles were reviewed (\u003cspan additionalcitationids=\"CR39 CR40 CR41 CR42 CR43 CR44 CR45\" citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e), and five RCTs met the inclusion criteria for the meta-analysis (\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e, \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e, \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e, \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e). For studies using the same sample, the most recent with complete outcome reporting was included (\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e, \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e). One study was excluded from the meta-analysis as it lacked a validated sleep quality measure, and the intervention differed from CBT-I (\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e)\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\n\u003ch3\u003eStudy quality assessment\u003c/h3\u003e\n\u003cp\u003eThe median score, as assessed using the QUALsyst tool, was 18 out of 20. The lowest score was 18 (\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e). The highest score was 20 (\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e, \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e, \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e, \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e). Among all the checklist items for assessing the quality of quantitative studies, Item 1, \u0026lsquo;Question or objective sufficiently described?\u0026rsquo; and Item 11, ' Conclusions supported by the results?\u0026rsquo; were most frequently reported. Criteria assessed for Item 9, \u0026lsquo;Controlled for confounding?\u0026rsquo;, were often not fully met. Scores for each study can be found in Appendix 4.\u003c/p\u003e \u003cp\u003eDue to limited studies, sensitivity and moderator analyses, and random-effects component network meta-analysis were not conducted.\u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eSummary of the evidence\u003c/h2\u003e \u003cdiv id=\"Sec12\" class=\"Section3\"\u003e \u003ch2\u003eCharacteristics of the studies\u003c/h2\u003e \u003cp\u003eNine studies on mHealth and eHealth interventions aimed at improving sleep duration and quality among adolescents were included in this systematic review (details in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e3\u003c/span\u003e). These studies involved 9,238 participants aged 12 to 24 years (Mean age: 15.6), with 50.3% male, 47.8% female, and 1.9% identifying as other (e.g., non-binary). Sleep was assessed using actigraphy (n\u0026thinsp;=\u0026thinsp;3) (\u003cspan additionalcitationids=\"CR41\" citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e) and/or questionnaires (n\u0026thinsp;=\u0026thinsp;8)(\u003cspan additionalcitationids=\"CR39 CR40 CR41 CR42 CR43 CR44\" citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e), including the Insomnia Severity Index (ISI)(\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e, \u003cspan additionalcitationids=\"CR44\" citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e), Pittsburgh Sleep Quality Index (PSQI) (\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e, \u003cspan additionalcitationids=\"CR44\" citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e), Sleep Condition Indicator 8-item version (SCI-8) (\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e), and Holland Sleep Disorder Questionnaire (HSDQ) (\u003cspan additionalcitationids=\"CR41\" citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e). One study measured daily mean sleep and intention to sleep without a validated tool(\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e). Intervention durations ranged from six to ten weeks (Median: 6 weeks). The RCTs were conducted in Australia (\u003cspan additionalcitationids=\"CR45\" citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e), Hong Kong(\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e), the Netherlands (\u003cspan additionalcitationids=\"CR41\" citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e), and the UK (\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e, \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e). One study focused on sleep promotion within a broader lifestyle intervention(\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e), while the remaining eight used dCBT-I. Among these, dCBT-I was applied to assess its efficacy (\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e), adding body scan mindfulness (\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e), or comparing modalities (email vs face-to-face)(\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e). Also, dCBT-I was used to reduce paranoia and hallucinations(\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e), improve psychopathology(\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e), depression (\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e)and address rumination in adolescents with depression(\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e). One study used dCBT for anxiety and insomnia, and the CBT-I component of that intervention was considered for this review(\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eEffectiveness of digital health interventions for Sleep in adolescents\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAuthor\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEffect on Sleep pre-post and follow-up intervention\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eEffect on psychopathology pre-post and follow-up intervention\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ede Bruin (2015, 2018)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eActigraphy SE, SOL, and TST revealed significant small to large effect sizes (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.30\u0026ndash;1.09), with the strongest effect size detected for SE (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.09).\u003c/p\u003e \u003cp\u003eEffects of improved SE and reduced SOL were maintained (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.10\u0026ndash;1.30) at two-month follow-up. WASO nor TIB reached statistical significance as measured by actigraphy at either point (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.11\u0026ndash;0.29).\u003c/p\u003e \u003cp\u003eSelf-reported sleep diary data, SE and SOL demonstrated significant effects of the intervention at post-intervention relative to the control group (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.56\u0026ndash;0.82), which were maintained at follow-up (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.52\u0026ndash;0.77). The strongest effect was for SE (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.56). Self-report SQ demonstrated a significant effect at both post and follow-up (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.41\u0026ndash;0.56). Self-report WASO, TIB, and TST did not reach statistical significance at either of the time points (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.17\u0026ndash;0.61).\u003c/p\u003e \u003cp\u003eThere were no statistical differences between the effects of the dCBT-i program relative to the group-based CBT-I program at post-test or follow-up.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePsychopathology outcomes at the 12-month follow-up for dCBT-i and the group-based CBT-I were, respectively: affective (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.87 and 0.97), anxiety (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.81 for dCBT-i), somatic (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.38 and \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.52), oppositional (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.42 for group-based CBT-I) and attention deficit hyperactivity disorder (ADHD) problems (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.47 and 0.46).\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ede Bruin (2020)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSleep improvements after treatment and follow-up for WASO and SE from actigraphy (\u003cem\u003e\u0026szlig;\u003c/em\u003e = \u0026minus; 0.38, p\u0026thinsp;\u0026lt;\u0026thinsp;.01, \u003cem\u003e\u0026szlig;\u003c/em\u003e = \u0026minus; 0.33, p\u0026thinsp;\u0026lt;\u0026thinsp;.05 for WASO, and \u003cem\u003e\u0026szlig;\u003c/em\u003e = 0.37, p\u0026thinsp;\u0026lt;\u0026thinsp;.01, \u003cem\u003e\u0026szlig;\u003c/em\u003e = 0.31, p\u0026thinsp;\u0026lt;\u0026thinsp;.05 for SE, respectively in the Body Scan group compared to the Non-body Scan group. Baseline to post-treatment for the subscales of shortness of sleep and irritation and the total score from the CSRQ (\u003cem\u003e\u0026szlig;\u003c/em\u003e = \u0026minus;0.50, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.05, \u003cem\u003e\u0026szlig;\u003c/em\u003e = \u0026minus; 0.53, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.001, \u0026szlig; = \u0026minus; 0.49, p\u0026thinsp;\u0026lt;\u0026thinsp;.05, respectively).\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChan (2022)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBoth groups, GT and ESH, showed a significant reduction in the ISI score after treatment compared with the WL group (GT vs WL: Cohen\u0026rsquo;s \u003cem\u003ed\u003c/em\u003e = -1.03; p\u0026thinsp;\u0026lt;\u0026thinsp;.001; ESH vs WL: \u003cem\u003ed\u003c/em\u003e=-0.63; p\u0026thinsp;=\u0026thinsp;.03). Likewise, both treatment groups had more significant overall clinical improvement (GT: \u003cem\u003ed\u003c/em\u003e=-1.54; p\u0026thinsp;\u0026lt;\u0026thinsp;.001; ESH: \u003cem\u003ed\u003c/em\u003e= -0.76; p\u0026thinsp;=\u0026thinsp;.03) in relative to the WL group after treatment. For sleep diary measures, the GT group had shorter SOL (\u003cem\u003ed\u003c/em\u003e =-0.50; p\u0026thinsp;=\u0026thinsp;.01) and higher SE (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.50; p\u0026thinsp;=\u0026thinsp;.01) than the WL group after treatment. The GT group also improved sleep quality after the intervention (GT vs WL: \u003cem\u003ed\u003c/em\u003e=- 1.04; p. \u0026lt;001)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDepression in the GT group shows a significant reduction using the HRSD (\u003cem\u003ed\u003c/em\u003e=-1.0, p\u0026thinsp;\u0026lt;\u0026thinsp;.001) but not in the ESH group (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.08) compared with the WL group.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFreeman (2017)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAfter treatment, 454 (62%) of 733 individuals in the treatment group and 326 (29%) of 1142 in the control group scored outside the clinical cutoff for insomnia used for trial entry. Compared with usual practice, the sleep intervention at 10 weeks reduced insomnia (adjusted difference 4\u0026middot;78, 95% CI 4\u0026middot;29 to 5\u0026middot;26, Cohen\u0026rsquo;s d\u0026thinsp;=\u0026thinsp;1\u0026middot;11; p\u0026thinsp;\u0026lt;\u0026thinsp;0\u0026middot;0001).\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCompared with usual practice the dCBT-I decreases paranoia (\u0026ndash;2\u0026middot;22,\u003c/p\u003e \u003cp\u003e\u0026ndash;2\u0026middot;98 to \u0026minus;\u0026thinsp;1\u0026middot;45, Cohen\u0026rsquo;s d\u0026thinsp;=\u0026thinsp;0\u0026middot;19; p\u0026thinsp;\u0026lt;\u0026thinsp;0\u0026middot;0001), and hallucinations (\u0026ndash;1\u0026middot;58, \u0026minus;\u0026thinsp;1\u0026middot;98 to \u0026minus;\u0026thinsp;1\u0026middot;18, Cohen\u0026rsquo;s d\u0026thinsp;=\u0026thinsp;0\u0026middot;24; p\u0026thinsp;\u0026lt;\u0026thinsp;0\u0026middot;0001). The mediation analyses indicated a change in sleep over three weeks, which explained 30% of the intervention effect on paranoia at ten weeks, with a change in sleep over ten weeks accounting for 58% of the treatment effect on paranoia.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMorris (2015)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMedium effect size for self-reported SQ as measured on the PSQI (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.51).\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDepression and anxiety did not show significant post-treatment effects (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.49\u0026ndash;0.51)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLi (2023)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eReductions in rumination did not differ between the intervention and control groups at postintervention, indicating dCBT-I had no significant effect on rumination. In contrast, there was a significantly greater reduction in unhelpful beliefs about sleep in the intervention group relative to the control group at post-intervention, 95% CI\u0026thinsp;=\u0026thinsp;0.09\u0026ndash;3.66, \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.24.\u003c/p\u003e \u003cp\u003eThus, neither rumination nor unhelpful beliefs about sleep emerged as significant mediators. However, the within-subject mediation analysis found rumination (Effect\u0026thinsp;=\u0026thinsp;0.56, 95% CI\u0026thinsp;=\u0026thinsp;0.06\u0026ndash;1.32), but not unhelpful beliefs about sleep, emerged as a significant mediator. This indicates that baseline-to-post-intervention reductions in rumination were associated with a baseline-to-post-intervention reduction in depression symptoms in the intervention group\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWerner-Seidler et al. (2023)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eInsomnia was a greater reduction in higher adheres compared to control group participants [t (189.1) = -2.62, p\u0026thinsp;=\u0026thinsp;.010, \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.50] and at follow-up [t (168.4) = -3.22, p\u0026thinsp;=\u0026thinsp;.001, \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.67]. Effect sizes were 0.50 (95% CI 0.15 to 0.85) post-intervention and 0.67 (95% CI 0.29 to 1.04) at follow-up. No reductions were found in the low-adherences and control group (PS\u0026thinsp;\u0026gt;\u0026thinsp;.05); effect sizes were 0.32 (95% CI -0.03 to 0.68) at post-intervention and 0.10 (95% CI -0.28 to 0.47) at follow-up\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDepression symptoms, with high adherers showing more significant reductions from baseline at post [t (181.5) = _2.95, p\u0026thinsp;=\u0026thinsp;.00, \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.46, 95% CI 0.11 to 0.80] and follow-up [t (160.6) = -2.48, p\u0026thinsp;=\u0026thinsp;.01, \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.48, 95% CI 0.11 to 0.85] compared to the control group. The effect sizes from this trial were in the small to medium range (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.27\u0026ndash;.41)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChampion (2023)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eThere was little evidence of an intervention effect on mean daily hours of sleep between the groups (post-treatment\u0026thinsp;=\u0026thinsp;0.997 (0.95 to 1.02), 12-month follow-up =\u0026thinsp;0.91(0.75 to 1.12), and 24-month follow-up =\u0026thinsp;0.91(0.72 to 1.14). The students (n\u0026thinsp;=\u0026thinsp;1960; 62.1%) who received sufficient doses had significantly greater mean knowledge of the Big 6 scores over 24 months relative to students in the control group and at each follow-up occasion (post-treatment\u0026thinsp;=\u0026thinsp;1.85 (1.53 to 2.16) 12-month follow-up =\u0026thinsp;0.97(0.69 to 1.26), and 24-month follow-up =\u0026thinsp;0.91(0.62 to 1.21).\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003eSE\u0026thinsp;=\u0026thinsp;Sleep Efficiency; Sleep Onset Latency (SOL); Total Sleep Time (TST), Wakefulness After Sleep Onset (WASO) nor Time in Bed (TIB), Sleep Quality (SQ), attention deficit hyperactivity disorder (ADHD), Chronic Sleep Reduction Questionnaire (CSRQ); digital cognitive behavioural therapy for Insomnia (dCBT-I); the Insomnia Severity Index (ISI); Group Therapy (GT) and email-delivered self-help (ESH); WL\u0026thinsp;=\u0026thinsp;Waiting group; Hamilton Rating Scale for Depression (HRSD); Pittsburgh Sleep Quality Index (PSQI)\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eIntervention characteristics\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e2\u003c/span\u003e outlines the intervention modality, duration, support level, behavioural components, completion rates, and follow-up details for each study. Three studies used the same dCBT-I, a website intervention (eHealth), adapted from an adult programme for adolescents(\u003cspan additionalcitationids=\"CR41\" citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e). One study adapted a sleep improvement programme for university students (\"\u003cem\u003eREFRESH\u003c/em\u003e\") to be delivered via email(\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e). Another used the \u0026lsquo;\u003cem\u003eSleepio\u0026rsquo;\u003c/em\u003e dCBT-I programme, combining website and mobile app delivery (e/mHealth)(\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e). One intervention, \"\u003cem\u003eInsomnia Relief\u003c/em\u003e,\" was delivered via website with text and email support (eHealth)(\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e). Two studies used the same chatbot app, \"\u003cem\u003eThe Sleep Ninja\u003c/em\u003e\" (mHealth)(\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e, \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e). A study focused on sleep promotion, through a holistic lifestyle, involved a school-based intervention, \"\u003cem\u003eHealth4life\u003c/em\u003e\" (e/mHealth), combining a cartoon-based website and education modules with a companion app encourage behaviour tracking(\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eActive Components and Delivery Formats of DHIs for Sleep\u003c/h2\u003e \u003cp\u003eTables\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e and \u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e2\u003c/span\u003e outlines the active components per study. Regarding educational components, Sleep Hygiene (SH) and Psychoeducation (PE) were included in all studies (n\u0026thinsp;=\u0026thinsp;9, 100%). However, different PE topics were delivered; for example, a study provides additional information about circadian components (e.g., morning light exposure) (\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e) or the process of sleep (\u003cspan additionalcitationids=\"CR40 CR41\" citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e); or general information about a healthy lifestyle (\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e). The Sleep Diary (SD) was mentioned in 5 studies (55.5%) (\u003cspan additionalcitationids=\"CR40 CR41 CR42\" citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e). Concerning cognitive components, the cognitive restructuring (CR) technique was mentioned in most studies (n\u0026thinsp;=\u0026thinsp;7; 77.7%) (\u003cspan additionalcitationids=\"CR40 CR41 CR42 CR43 CR44\" citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e), followed by Constructive Worry (CW) in six studies (66.6%), and third-wave therapy (TW) (mindfulness) was included in 3 studies (33.3%) (\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e, \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e, \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e). A study described in detail and tested the additional TW component, which incorporated a 20-minute auditory of \u0026lsquo;body scan meditation\u0026rsquo; from a licensed Mindfulness-based Stress Reduction (MBSR)/ Mindfulness-based Cognitive Therapy (MBCT) therapist and was introduced in session two. In sessions three to six, the body scan meditation was reviewed, and further explanation of its possible effects on stress, arousal, and relaxation, and how these relate to sleep problems was provided (\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e). Finally, one study included the paradoxical intention (PI) component (\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e). Concerning behavioural components, Stimulus Control (SC) was mentioned in most of the studies (n\u0026thinsp;=\u0026thinsp;8; 88.8%) (\u003cspan additionalcitationids=\"CR39 CR40 CR41 CR42 CR43 CR44\" citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e), followed by Sleep Restriction (SR) and Relaxation (RT), using particularly progressive muscle relaxation (n\u0026thinsp;=\u0026thinsp;6; 66%)(\u003cspan additionalcitationids=\"CR39 CR40 CR41 CR42\" citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e). Also, two studies (22.2%) used Guided Imagery (GI)(\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e, \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e). In terms of delivery formats, most interventions were delivered using automatic messages (n\u0026thinsp;=\u0026thinsp;4, 44.4%) (\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e, \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e, \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e, \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e). A study used online therapeutic guidance (weekly online sessions with a sleep expert)(\u003cspan additionalcitationids=\"CR41\" citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e). Another study included an optional human encouragement (online and teacher-delivered activities to reinforce the key message and encouragement discussion)(\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e). Finally, a study did not incorporate any technical or human delivery, making the intervention completely unguided (\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e). The components and delivery format used in the trials are presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003eIntervention effects\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e3\u003c/span\u003e outlines the effects of the interventions. Five dCBT-I trials demonstrated significant effects, ranging from small to large, including objective and subjective measures on sleep outcomes (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.17\u0026ndash;1.30), compared to the control condition on primary sleep outcomes post-intervention (\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e, \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e, \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e, \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e). The dCBT-I exhibited a medium positive effect (n\u0026thinsp;=\u0026thinsp;5; g\u0026thinsp;=\u0026thinsp;0.58, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.01) on subjective SQ immediately after treatment when comparing the control groups. In the case of the \u003cem\u003eHealth4life\u003c/em\u003e intervention (\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e) there was little evidence of an intervention effect on mean daily hours of sleep between the groups (post-treatment\u0026thinsp;=\u0026thinsp;0.997 (0.95 to 1.02), 12-month follow-up =\u0026thinsp;0.91(0.75 to 1.12), and 24-month follow-up =\u0026thinsp;0.91 (0.72 to 1.14). Also, the dCBT-I improved psychopathology in the population and showed small and medium effects, including effects on depression (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.49\u0026ndash;1.0)(\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e), anxiety, ADHD (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.47\u0026thinsp;\u0026minus;\u0026thinsp;0.46)(\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e), paranoia (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.19), and hallucinations (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.24)(\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003eMeta-Analysis: Short and long-term Sleep Quality (SQ)\u003c/h2\u003e \u003cp\u003eThe pooled effect sizes after the treatment and at the follow-up subjective SQ were calculated to identify the short- and long-term effects of dCBT-I. Three studies conducted follow-up evaluations, specifically at weeks 14 and 22 from treatment initiation (equivalent to three months after the posttreatment evaluation)(\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e) and two months after treatment completion(\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e). One study performed follow-ups at 2, 6, and 12 months after treatment (\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e) the results of the two-month follow-up were included to match the other studies' time points and calculate the pooled effect size for long-term effects. Chan, Lam (\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e) was excluded from the analysis because follow-up data on the waiting group were not reported. Scores on the PSQI, ISI and HSDQi after treatment or at the follow-up evaluation were employed as the primary sleep outcomes for meta-analysis. The effect size for subjective SQ was significant for the posttreatment evaluation (n\u0026thinsp;=\u0026thinsp;5; g\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;0.64 [95% CI\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;1.02, \u0026minus;\u0026thinsp;0.25]) but not for the follow-up evaluation (n\u0026thinsp;=\u0026thinsp;3; g\u0026thinsp;=\u0026thinsp;0.54 [95% CI\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;1.02, 0.25], in which only three studies provided follow-up measures with the control group (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). High heterogeneity in the subjective SQ after treatment and at the follow-up was also noted (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e,\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e,\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis review summarises the evidence of active components of DHIs for sleep promotion, treatment, and prevention of insomnia among adolescents and examines their effectiveness. In terms of educational components, all interventions included HS and PE, while three dCBT-I trials included SD. Even though education alone is not sufficient to ensure effectiveness in treating insomnia (\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e), it remains a recommended component of the CBT-I package(\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). In particular, SD has demonstrated validity, clinical utility, and usability for providing feedback for SQ to individuals (\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e). As a result, SD may have an additional effect as an active component in sleep interventions in combination with HS and PE. The three trials in this review using SD showed moderate effects on SQ after intervention and follow-up (\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e, \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e). Hence, future sleep interventions should consider SD to enhance effectiveness.\u003c/p\u003e \u003cp\u003eIn terms of cognitive components, CR was utilised in most studies (n\u0026thinsp;=\u0026thinsp;7, 77%). CR aims to modify maladaptive thought patterns contributing to insomnia (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). This approach is consistent with transdiagnostic models, which posit that changes in cognitive patterns can positively impact a range of common mental health conditions (\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e). For example, in this review, Morris et al (\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e) demonstrated that CBT-I could also mitigate symptoms of anxiety. Similarly, this review identified comparable effects on depressive symptoms (\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e, \u003cspan additionalcitationids=\"CR44\" citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e), underscoring the potential transdiagnostic applications of CBT-I. Additionally, CW emerged as a significant component, appearing in six studies (66.6%), thus emphasising the relevance of rumination in sleep interventions. Despite the established role of rumination as a critical mechanism of change in both depression and insomnia, only one study conducted a mediation analysis to explore its impact (\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e). The authors revealed that addressing rumination as a mediating variable can enhance the effectiveness of sleep interventions for youth with comorbid psychopathology. Consequently, CR and CW should be integrated into CBT-I protocols and other behavioural sleep interventions, given their status as a maintenance variable and a transdiagnostic process implicated in various mental disorders, including insomnia (\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e, \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e). The TW components, particularly mindfulness, were used in 3 studies (33.3%). TW has indicated an additional effect of CBT-I in adult interventions(\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e). In this review de Bruin, Meijer (\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e) study showed that using a body scan meditation (BSM) in CBT-I may have an additional positive effect on sleep, above and beyond the impact of the traditional CBT-I techniques in adolescents. Studies have suggested that the differences are due to adolescents having higher levels of sleep motor activity than adults (\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e). Therefore, BSM might have an extra effect on the intervention, affecting both the physical arousal caused by worry and the worry itself by affecting the process that ties these two together. Thus, TW and particularly BSM can benefit adolescents by decreasing physiological arousal and prolonging calm respiration awareness. Therefore, TW should be considered in future adolescent protocol interventions for sleep. It is important to note that none of the studies included acceptance and commitment therapy as part of TW, which has been effective in treating insomnia in adults (\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e); an approach that requires further exploration for this age group in digital sleep interventions. Only one study included the Paradoxical intention (PI) component (\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e), considered an evidence-based single component for insomnia that has the potential to reduce sleep onset latency (SOL), the number of awakenings, and sleep performance anxiety (\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e). The intervention \u003cem\u003eSleepio\u003c/em\u003e by Freeman, Sheaves (\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e) showed moderate-sized effects in reducing insomnia symptoms, comparable to other studies in this review without the PI component. This component may have potential effects on comorbid mental health conditions, such as anxiety and depression, helping to distract from worry and rumination, and is a recommended component to incorporate as part of the dCBT-I package (\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e). Due to the lack of studies on dCBT-I in adolescents, we cannot assume that PI does not play a significant role.\u003c/p\u003e \u003cp\u003eRegarding behavioural components, the SC was part of all CBT-I studies. CS is considered a standalone treatment for insomnia and the most widely used component (\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e). However, the mechanism of action in SC is poorly understood due to the several variations of the instructions in the literature (\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e). The studies in this review did not mention implementation details, which suggests that they varied between the trials. However, SC is effective in reducing insomnia symptoms compared with control groups in adults (\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e)and could be used as the sole behavioural intervention when adherence to SR or other CBT-I components is a significant challenge for the clients(\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e), making SC a critical active component. Concerning SR, it was used in most of the CBT-I trials (n\u0026thinsp;=\u0026thinsp;4, 44.4%) in this review. SR is often claimed to be the most effective standalone intervention in the treatment of insomnia (\u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e). In this review, one dCBT-I trial, \u003cem\u003ethe Sleep Ninja App\u003c/em\u003e did not include SR (\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e), a decision made after parent consultation and adolescents, given the program's unguided format and the participants' age. Also, the program was delivered with a briefer CBT-I (1 hour) compared with the traditional face-to-face (6 hours) and other digital interventions, such as \u003cem\u003eSleepio\u003c/em\u003e (3-6hs). However, \u003cem\u003ethe Sleep Ninja App\u003c/em\u003e showed moderate effects in reducing insomnia symptoms relative to the control group, which can suggest that the SR component in fully automatic DHIs in early adolescents can be omitted, specifically when it is not targeting participants with chronic insomnia.\u003c/p\u003e \u003cp\u003eRelated to relaxation therapies (RT), Guided Imagery (GI) was used in 2 studies (22.2%) (\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e, \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e). GI has been recommended as a combination of mind/body techniques that appear to work synergistically(\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e). The same studies accompanied progressive muscle relaxation in combination with GI and demonstrated decreased physiological activation, contributing to adolescent relaxation. Two trials have a sole progressive muscle relaxation component (\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e, \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e), assessed as part of the CBT-I package; it is unclear whether this component alone has a different effect. However, the literature has shown that muscle relaxation is efficacious alongside other CBT-I packages but not as a standalone component (\u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e56\u003c/span\u003e). In this review, \u003cem\u003ethe Ninja App\u003c/em\u003e intervention did not include any relaxation therapy component (\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e) and showed a medium effect size in reducing insomnia symptoms. Since this is an unguided programme, the RT component may be considered an optional approach when implemented as part of the dCBT-I package.\u003c/p\u003e \u003cp\u003eAmong the studies, most were delivered unguided with automatic messages (n\u0026thinsp;=\u0026thinsp;4; 44.4%), indicating the potential scalability of DHI for sleep. It is noted that only one trial included a guided intervention with an expert; the intervention was delivered to adolescents with an insomnia diagnosis, which differed from the other trials, which included participants with symptoms of insomnia, making it a support for participants with severe symptoms, also recommended in DHI. Various elements have been considered in digital interventions for sleep, such as how to deliver the treatment (e.g., email, website, mobile App) and the appropriate level of support (e.g., reminders, synchronous, asynchronous messages, human support)(\u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e57\u003c/span\u003e). Interestingly, most studies do not include human support in this review, providing evidence of the potential scalability of these interventions within the population to prevent and treat insomnia. For example, in this review, Chan, Lam (\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e) delivered the intervention by email with no synchronic, asynchrony, or human support. Also, the \u003cem\u003eSleep Ninja\u003c/em\u003e programme was delivered fully automatically using a chatbot. Each module lasted 5\u0026ndash;10 minutes and was spaced sequentially over a minimum of 3 weeks (1 hour). Compared to other dCBT-I or traditional face-to-face CBT-I packages that require a minimum of 6 hours (\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e)(de Bruin et al., 2014), that intervention was the briefest. The authors showed that the small bites of therapeutic content for behavioural change were sufficient, considering the medium effect size shown in the intervention. The results may suggest that this approach can be scaled up for the general population, promoting sleep in the public health domain.\u003c/p\u003e \u003cdiv id=\"Sec18\" class=\"Section2\"\u003e \u003ch2\u003eEffectiveness\u003c/h2\u003e \u003cp\u003eOur findings indicate that dCBT-I effectively treats adolescent insomnia. One study examined sleep promotion within a holistic lifestyle intervention, but did not find a significant impact on behavioural change (\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e). dCBT-i exhibited a medium positive effect on subjective SQ immediately after treatment compared to control groups, though no significant treatment effect of dCBT-i at the follow-up was discovered. Further, no significant improvements in objective SQ (i.e., SE) were noted (Only one trial reported actigraphy(\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e)). Interestingly, the effect size was of higher magnitude for participants with clinically significant insomnia, regarding short-term and long-term efficacy, compared to the control intervention. Finally, psychopathology improved with the dCBT-i exhibited small to medium positive outcomes compared to control groups.\u003c/p\u003e \u003cp\u003eThree trials in this review (\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e, \u003cspan additionalcitationids=\"CR44\" citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e), showed a medium effect size, reducing insomnia symptoms and small effects of depression. Similarly, in the case of anxiety, with a small effect in reducing the symptoms and a moderate effect in reducing insomnia symptoms (\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e). These findings contribute to emerging evidence of the positive effects of digital sleep interventions and indicate a mechanistic and potentially causal role for insomnia symptoms in depression and anxiety, consistent with studies on adults (\u003cspan citationid=\"CR58\" class=\"CitationRef\"\u003e58\u003c/span\u003e, \u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e59\u003c/span\u003e). Also, findings in the adolescent population indicate that cognitive processes are crucial in perpetuating or ameliorating adolescent insomnia, but little is known about which facets of insomnia can be affected by interventions that target these processes in adolescents (\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e). Due to the high comorbidity between mood disorders and insomnia, it might be possible that the reduction of mood symptoms is partly due to the restoration of good sleep, implying the mediating effect of sleep in the trajectory of mood-related psychopathology.\u003c/p\u003e \u003cp\u003eIn Sleep Efficiency (SE), Sleep Onset Latency (SOL), and Total Sleep Time (TST), as measured by actigraphy, revealed significant small to large effect sizes (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.30\u0026ndash;1.09), with the strongest effect size detected for SE (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.09). Effects of improved SE and reduced SOL were maintained at the two-month follow-up (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.10\u0026ndash;1.30)(\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e). Unfortunately, only one trial in this review has used actigraphy measures to determine adolescent sleep patterns. Future studies should include objective measures like actigraphy to gain a more comprehensive understanding of how the intervention affects sleep in this population.\u003c/p\u003e \u003cp\u003eIn the case of e/m health-promoting sleep by Campion (2023) (\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e), the outcomes did not show significant differences related to sleep. Simultaneous prevention/promotion interventions require more studies, as it is not clear which component affects direct or indirect behaviours, such as sleep (\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e). However, the study potentially indicates that adolescents could learn preventive information about the Big 6 lifestyle factors, which may not be transferable to behavioural change. Future RCT studies of adolescent sleep promotion is needed, including components other than psychoeducation and sleep hygiene. Evidence has shown that CBT-I can also prevent insomnia and support other comorbid mental health conditions (\u003cspan citationid=\"CR58\" class=\"CitationRef\"\u003e58\u003c/span\u003e, \u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e59\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eConcerning attrition and drop-out, the dropout rate in the studies was high, particularly in Freeman et al (\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e). The dropout from that study assessment was high (50%) during the study and was greater in the treatment group than in the control group. Werner-Seidler et al (\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e)showed significant differences regarding the effect of sleep and depression on adherence and non-adherence. In the same way, Champion et al.(\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e) mentioned that the group who received the intended doses showed greater knowledge. Future studies should evaluate high and low adherence and dose, considering the differences in the intervention effect compared to the control group.\u003c/p\u003e \u003cp\u003eFurthermore, an additional hint that might enhance adherence among younger adolescents (between 10 and 13 years) is the participation of parents in the intervention due to the crucial role they have in influencing adolescent health behaviours (\u003cspan citationid=\"CR61\" class=\"CitationRef\"\u003e61\u003c/span\u003e). Only two studies in this review included parents(\u003cspan additionalcitationids=\"CR41\" citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e, \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e). A systematic review showed that parent-based interventions with adolescent components were associated with positive program effects(\u003cspan citationid=\"CR62\" class=\"CitationRef\"\u003e62\u003c/span\u003e). Future studies may consider the participation of the parents or caregivers as part of the sleep intervention.\u003c/p\u003e \u003cp\u003eThe results of this study suggest that including sleep interventions in mental health protocols can enhance the effectiveness of current interventions. Behavioural sleep interventions are often overlooked in these protocols and adding them could potentially improve overall outcomes. The study pointed out the importance of sleep difficulties for mental health in adolescents and the need for reconsideration of clinical services with a priority given to improving sleep.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec19\" class=\"Section2\"\u003e \u003ch2\u003eStrengths and Limitations\u003c/h2\u003e \u003cp\u003eOur review has several strengths. First, we performed a comprehensive and up-to-date systematic review, allowing the inclusion of RCTs of DHIs for sleep. To our knowledge, this is the first review of the active components of DHIs for sleep promotion and insomnia in adolescents. Second, we used evidence-based components to assess the dCBT-I intervention delivery formats. Identifying the components is key to conducting this review. We made and reviewed a table of the definitions of components a priori from previous studies (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Third, our findings showed that DHIs are an effective alternative and scalable intervention for adolescents, who often do not have access to behavioural interventions for sleep problems. The review also shows evidence of active components for sleep interventions (PE, HS, SC, and TW) able to be used didactically and implemented in different groups and contexts with minimal human assistance.\u003c/p\u003e \u003cp\u003eOur analytic approach was dichotomously defined components as either present or absent based on the descriptions provided in the studies, which may be considered a limitation because this approach does not consider possible variation in implementation. Furthermore, some components may have overlapping contents, such as PE and HS, even though their procedures and supposed mechanisms of action are distinct enough to be considered and evaluated as different components. Larger trials specifically designed to test the efficacy of various components are needed to determine if specific combinations are more effective than others. In 3 studies, the COVID-19 pandemic may have affected the outcomes of the interventions, increasing, for instance, screen time (\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e) and anxiety symptoms (\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e, \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e). Throughout the pandemic, adolescents experienced substantial disruptions to schooling, employment, and peer relationships, and effects on health behaviours among youths have been documented worldwide; therefore, those outcomes must be analysed with caution. Most studies did not collect objective data and relied on self-report surveys. Only one trial reported actigraphy data (\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e). The studies were developed and conducted in high-income countries and most Western countries. Only one study was conducted in Asia (Hong Kong). Also, middle or upper socioeconomic status and living in major cities in the trials limit the generalisability of the results. Future studies should recruit populations with greater cultural and socioeconomic diversity.\u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThe studies in this review show that dCBT-I is likely to lead to reductions in overall insomnia and also reductions in other mental health symptoms such as depression and anxiety (\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e, \u003cspan additionalcitationids=\"CR44\" citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e), even psychotic symptoms (hallucinations) (\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e). It might also be possible that mindfulness, relaxation strategies, and cognitive restructuring in the CBT-I treatment contributed to improving mental health-related outcomes.\u003c/p\u003e \u003cp\u003eIn conclusion, based on the literature review and the outcomes in this review, we recommend including the following active components in the DHIs package for promotion, prevention, or insomnia treatment: SD, mainly as part of education components, along with HD and PE, regarding cognitive components, CR, CW and TW. Regarding behavioural components, SC and optional SR are when the intervention is fully automatic with early adolescents, and RT is an optional component.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eConflict of interest\u003c/h2\u003e \u003cp\u003eThe authors do not have any conflicts of interest to disclose.\u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eThis review was supported by the Agency for Science, Research and Technology (ASTAR), Institute for Human Development and Potential (IHDP). The views expressed are those of the author(s) and not necessarily those of ASTAR, IHDP.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eAS-S: Conceptualization; writing the original draft; methodology; writing, reviewing and editing; formal analysis; data curation; validation. AF: Methodology, validation, review, and editing; formal analysis. NP: Meta-analysis and review of study quality. AR and JE: Review and editing; validation. All authors have read and commented on the manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eWe wish to express our gratitude to Kiran Kaur for supporting and carrying out the database search\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eBruce ES, Lunt L, McDonagh JE. Sleep in adolescents and young adults. Clinical medicine. 2017;17(5):424.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePatton GC, Olsson CA, Skirbekk V, Saffery R, Wlodek ME, Azzopardi PS, et al. Adolescence and the next generation. Nature. 2018;554(7693):458\u0026ndash;66.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSawyer SM, Azzopardi PS, Wickremarathne D, Patton GC. The age of adolescence. The lancet child \u0026amp; adolescent health. 2018;2(3):223\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePark H, Chiang JJ, Irwin MR, Bower JE, McCreath H, Fuligni AJ. 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Preventive medicine. 2022;164:107247.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Table 2","content":"\u003cp\u003eTable 2 is available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"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":"npj-digital-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"npjdigitalmed","sideBox":"Learn more about [npj Digital Medicine](http://www.nature.com/npjdigitalmed/)","snPcode":"41746","submissionUrl":"https://submission.springernature.com/new-submission/41746/3","title":"npj Digital Medicine","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"NPJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Digital-health-intervention, sleep, insomnia, cognitive-behavioural-therapy, adolescents","lastPublishedDoi":"10.21203/rs.3.rs-6609677/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6609677/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eDigital Health Interventions (DHIs) for promoting sleep, treating, and preventing insomnia are a scalable, accessible, and resource-efficient alternative to traditional interventions. Though sleep problems are common in adolescents, limited research has focused on this age group. The appropriateness of DHIs for sleep promotion or insomnia treatment in adolescent populations, along with the active components associated with effective interventions, needs to be assessed. This review evaluated effective DHIs for sleep among adolescents and distilled their active components.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eRandomized Controlled Trials (RCTs) were selected from OVID (Medline), CINAHL, Web of Science, SCOPUS, PsycINFO, and Embase databases from their inception to June 30, 2023, and updated in May 2024. Adolescence was defined as the phase of life stretching between childhood and adulthood (10 to 24 years old).\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eNine studies were identified, involving 9238 participants, of whom n\u0026thinsp;=\u0026thinsp;4498 (47.8%) were females, between 12 and 24 years old (Mean: 15.6 years). Eight studies focused on digital cognitive behavioural therapy for insomnia dCBT-I, and one study focused on a holistic lifestyle DHI. Most studies delivered the DHI unguided using automatic messages (n\u0026thinsp;=\u0026thinsp;4; 44.4%). dCBT-I for adolescents demonstrated a medium positive effect (n\u0026thinsp;=\u0026thinsp;5; g =- 0.64, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.01) on subjective sleep quality immediately after treatment. Results suggested that active components of effective dCBT-I for adolescents are cognitive restructuring, mindfulness, stimulus control sleep, and optional sleep restriction technique.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eThe findings suggest that dCBT-I could be beneficial for insomnia and comorbid mental health in adolescents. Possible active component interventions may include a sleep diary, as part of education, cognitive restructuring, mindfulness, and stimulus control.\u003c/p\u003e","manuscriptTitle":"Active Components in Digital Health Interventions for Sleep among Adolescents: A Systematic Review and Meta-Analysis of Randomized Controlled Trials","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-09 11:26:37","doi":"10.21203/rs.3.rs-6609677/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-06-14T16:15:43+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-11T10:40:38+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"308944568070228774280030735394278089919","date":"2025-06-09T08:12:57+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"5421836214686593903496712971055532924","date":"2025-05-30T07:30:38+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-29T08:23:23+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"145984130977595371798839293344225051579","date":"2025-05-16T10:40:38+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-05-15T15:20:10+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-05-15T15:08:47+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-05-15T07:23:52+00:00","index":"","fulltext":""},{"type":"submitted","content":"npj Digital Medicine","date":"2025-05-07T08:07:19+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"npj-digital-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"npjdigitalmed","sideBox":"Learn more about [npj Digital Medicine](http://www.nature.com/npjdigitalmed/)","snPcode":"41746","submissionUrl":"https://submission.springernature.com/new-submission/41746/3","title":"npj Digital Medicine","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"NPJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"d27ebaa9-9e05-4af8-815a-7b776f6f6cbf","owner":[],"postedDate":"May 9th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":48184224,"name":"Biological sciences/Psychology"},{"id":48184225,"name":"Health sciences/Diseases"},{"id":48184226,"name":"Health sciences/Health care"},{"id":48184227,"name":"Scientific community and society/Social sciences"}],"tags":[],"updatedAt":"2025-12-08T16:00:25+00:00","versionOfRecord":{"articleIdentity":"rs-6609677","link":"https://doi.org/10.1038/s41746-025-02152-6","journal":{"identity":"npj-digital-medicine","isVorOnly":false,"title":"npj Digital Medicine"},"publishedOn":"2025-12-04 15:57:21","publishedOnDateReadable":"December 4th, 2025"},"versionCreatedAt":"2025-05-09 11:26:37","video":"","vorDoi":"10.1038/s41746-025-02152-6","vorDoiUrl":"https://doi.org/10.1038/s41746-025-02152-6","workflowStages":[]},"version":"v1","identity":"rs-6609677","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6609677","identity":"rs-6609677","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}