Description of the nationally implemented National Health Service Digital Diabetes Prevention Programme intervention and rationale for its development: mixed methods study

Description of the nationally implemented National Health Service Digital Diabetes Prevention Programme intervention and rationale for its development: mixed methods study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Description of the nationally implemented National Health Service Digital Diabetes Prevention Programme intervention and rationale for its development: mixed methods study Lisa M Miles, Rhiannon E Hawkes, David P French This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-2152186/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 18 Apr, 2023 Read the published version in BMC Health Services Research → Version 1 posted 10 You are reading this latest preprint version Abstract Background The National Health Service (NHS) Digital Diabetes Prevention Programme (DDPP) is a behaviour change programme for adults in England who are at high risk of developing type 2 diabetes. Four independent providers deliver the NHS-DDPP following a competitive tendering process. Although providers work to a single service specification, there is potential for some variation in the service across providers. This study 1) assesses fidelity of the structural features of the design of the NHS-DDPP compared to the service specification, 2) describes the structural features of delivery of the NHS-DDPP as implemented 3) reports developers’ views on how the structural components of the NHS-DDPP were developed and why changes were made following implementation. Methods Using mixed methods, we conducted a document review of providers’ NHS-DDPP design and delivery documentation, and extracted information using the Template for Intervention Description and Replication checklist, which was adapted to capture features of digital delivery. Documentation was supplemented by content analysis of interviews with 12 health coaches involved in delivering the NHS-DDPP. Semi-structured interviews were also conducted with 6 programme developers employed by the digital providers. Results Provider plans for the NHS-DDPP show relatively high fidelity to the NHS service specification. Despite this, there was wide variation in structural features of delivery of the NHS-DDPP across providers, particularly for delivery of ‘support’ (e.g. use, dose and scheduling of health coaching and/or group support). Interviews with developers of the programmes showed that much of this variation is likely to be attributable to the origin of each provider’s programme, which was usually a pre-existing programme that was adapted to conform to the NHS-DDPP service specification. The NHS-DDPP is continually improved and developed based on user experience feedback and research conducted by the providers. Conclusions Indirect evidence suggests that variation in delivery of support could affect effectiveness of the NHS-DDPP. A priority for future research is ascertaining whether the variation in delivery of the NHS-DDPP across providers is related to any differences in health outcomes. It is recommended that future rounds of commissioning the NHS-DDPP pre-specify the type of support participants should receive, including expected dose and scheduling. diabetes prevention digital interventions fidelity support TIDieR behaviour change Background Type 2 diabetes mellitus (T2DM) is a major public health concern that is largely preventable by weight loss and improved diet and physical activity. Following the success of diabetes prevention trials [ 1 – 3 ], several diabetes prevention programmes have been implemented around the world [ 4 , 5 ]. In 2016, the National Health Service (NHS) in England implemented the Healthier You: NHS Diabetes Prevention Programme (NHS-DPP) for adults at risk of developing T2DM. The NHS-DPP is a behaviour change programme delivered in groups which aimed to support participants improve dietary and physical activity behaviours, and prevent progression to T2DM. It has been rolled out in waves, gradually reaching universal national coverage [ 6 ]. Delivery of the NHS-DPP is procured through a national competitive process, organised by NHS England (NHSE); this was originally conducted through a Framework Agreement in 2016 (Framework 1), in which four providers were selected to deliver a face-to-face version of the programme [ 7 ]. Early favourable health outcomes from the NHS-DPP have been reported [ 6 , 8 ], but it has been suggested that measures are needed to improve uptake and retention on the programme for younger people, those in employment, minority ethnic and deprived groups and those reporting a disability [ 9 ]. A digital version of the NHS-DPP was piloted in 2017/2018; participation in the programme was associated with clinically significant reductions in weight (-3.1kg) and HbA1c (-1.6mmol/mol) at 12 months [ 10 ]. These changes have been shown to be comparable to those of the face-to-face programme [ 11 ]. The NHS-DPP was then re-procured in 2019, when a number of enhancements were made to the service specification, including the introduction of a digital DPP service as an adjunct to the face-to-face service (Framework 2). At this point, five providers were selected to deliver the face-to-face group service by NHSE to provide NHS DPP across England: four of the previous providers plus one new provider [ 7 ]. Four of these five providers sub-contracted digital providers to deliver the digital service (NHS-DDPP). This resulted in important partnerships between providers of the face-to-face and digital programmes. As part of the competitive process to secure contracts to deliver the programme, face-to-face and digital providers worked together to submit a Framework 2 response describing their proposed service delivery and planned content. During delivery of the service under Framework 2, one digital provider contract ended. The remaining four digital providers are commercial entities. NHSE produced a Framework 2 service specification [ 12 ] detailing the key features that should be present in the NHS-DPP [ 12 ] based on the currently available evidence [ 13 , 14 ]. The present research examines the fidelity of each digital providers’ programme to this specification. Intervention fidelity refers to whether an intervention was designed, delivered and received as planned [ 15 ]. An assessment of fidelity is important to fully understand the reasons why interventions are effective or not. Without it, reports of an effective intervention could be a function of either an effective intervention or the influence of other unknown factors added to or omitted from the intervention [ 16 ]. Our research team has reported extensively on the fidelity of the behaviour change content of face-to-face and digital versions of the NHS-DPP [ 17 – 20 ]. In the present study we assess the fidelity of the structural features (such as materials and mode of delivery) of the design of the NHS-DDPP compared to the NHS service specification, and describe the delivery of the NHS-DDPP using the Template for Intervention Description and Replications (TIDieR) checklist [ 21 ]. The TIDieR checklist has been developed as part of a movement towards standardised reporting of non-pharmacological interventions. Accurate description of interventions is important to facilitate replicability and implementation beyond randomised controlled trials (RCTs). In addition to an assessment of fidelity to the service specification, it is also important to fully document the reasons for changes in key structural features of delivery of the NHS-DDPP as it is implemented. Although the programme is commissioned centrally by NHSE and each provider is working to a single service specification, because the programme is delivered by multiple providers, there is potential for some variation in the service across providers. It is important to understand what (if any) variation occurs as the programme is implemented. Further, it is informative to explore the journey by which the provider programmes were developed, to explain how and why the programmes were structured as they are. Such findings can provide important context for further evaluative work on the NHS-DDPP and further inform implementation of the NHS-DPP and other similar programmes. A mixed methods approach has been chosen to document the structural features of the NHS-DDPP (quantitative) and the evolution of the provider programmes throughout the journey of development and implementation (qualitative). Specifically, the objectives of the present study are firstly to: 1) compare the structural features of the NHS-DDPP design to the NHS service specification for the programme (fidelity); 2) describe the structural features of the delivery of the NHS-DDPP using TIDieR (highlighting variation across providers and any modifications introduced following implementation). Secondly, a series of interviews with NHS-DDPP programme developers has allowed a qualitative assessment of 3) how the structural components of the NHS-DDPP were developed and why changes were made to the programme following implementation. Methods Design This study used a mixed-methods design. Components of the NHS-DDPP were content-analysed for structural features of design (objective 1) and delivery (objective 2). Semi-structured interviews investigated how the NHS-DDPP was developed and any rationale for any changes made to the NHS-DDPP once implemented (objective 3). Document review Programme specification documents The programme specification documents for the NHS-DDPP indicate the key content that should be included in the programme, and comprise of the NHS service specification [12] and NICE Guideline PH38 on Type 2 Diabetes: Prevention in People at High Risk [14]. The former was specific to commissioning of the NHS-DPP (including face-to-face and digital offerings in Framework 2 and was based on an evidence review of lifestyle interventions for the prevention of T2DM [13] and drew on recommendations from NICE PH38 guideline [14]. The NICE PH38 guideline provided additional information regarding behaviour change content to be included in diabetes prevention programmes and was referred to in the NHS Service Specification [12]. Key structural features from these specification documents have been identified in a previous study [22] and have been used again here as a basis for assessing fidelity in the current study. Design materials The design documentation supplied by each digital provider to the research team has been described previously [17]. In brief, this comprises Framework 2 response bids each provider submitted to NHSE (by 15th October 2018), during procurement and supplementary information (further documentation and/or email correspondence) obtained from providers between June 2020 and April 2021. Analysis The design of each provider version of the NHS-DDPP was described using the TIDieR checklist [21]. TIDieR items (e.g. materials, procedures, modes of delivery) were extracted by REH from the Framework 2 responses; TIDieR items were later extracted by LMM from supplementary design information from providers. The final TIDieR description was checked with the service provider for accuracy. Results were tabulated and compared with requirements in the NHS specification as an assessment of fidelity. Delivery materials The delivery documentation provided by each digital provider to the research team has been described previously [20] and is detailed in Additional file 1. This comprised: Guest access to smartphone and web applications for three out of the four providers. The other provider supplied an app user guide. All educational materials, including learning platforms, online articles, PDF articles, videos, online workbooks and additional workbooks posted to service users. Standard text/script sent to service users via email and text messages. Interviews with health coaches Further, a series of semi-structured interviews were conducted with health coaches who are actively involved in delivering the NHS-DDPP. A total of two, four, two and four interviews (n = 12) were conducted with health coaches from providers 1, 2, 3 and 4 respectively between July and November 2021. Recruitment and informed consent procedures for health coaches taking part in the interviews are described elsewhere [20]. In brief, interviews were conducted via the video conferencing platform Zoom and covered the following topics of relevance to the present study: Participants’ professional background and any training received. Participants’ role in supporting service users throughout the programme (e.g. at first contact, continued engagement, coaching via telephone/video calls and/or online chat, moderating support forums). Participant’s role in tailoring or personalising coaching to individuals. Content of the digital intervention, including the format of intervention features included in the programme and any modifications that have been made. The full topic guide for the interviews is available in Additional file 2. Analysis Although the TIDieR checklist [21] has been found to be a useful tool for applied health research studies [23], it was originally developed before the rapid growth in availability and application of digital health interventions. We therefore considered recent literature relevant to describing digital health interventions [24-26] and adapted the items in the TIDieR checklist to better reflect description of a nationally implemented digital health intervention (NHS-DDPP). Specifically, items 6 (‘how’), 8 (‘when and how much’) and 9 (‘tailoring’) have had sub- items added to carefully describe format of delivery, details of scheduling of different procedures (information sessions and health coaching) and nature of tailoring,. These changes are largely built on a framework for form of delivery (which includes all features through which behaviour change intervention content is conveyed including: the provider, format, materials, setting, intensity, tailoring, and style) [26] and informed by important aspects of delivery highlighted in an ontology for specifying the mode of delivery of interventions [24] (namely, adding’ interactivity’). In addition, we acted on a recommendation [23] to include a column in the TIDieR checklist for ‘modifications’, so that changes to the programme since implementation could be captured (see Additional file 3 for adapted TIDieR checklist). Further, we decided to not report rationale, theory and goals of the NHS-DDPP from item 2 of the TIDieR checklist (‘why’) in the current study, as this has already been reported in previous work by the research team regarding theoretical underpinnings of the NHS-DDPP [17]. The adapted TIDieR checklist was used by LMM and REH to extract relevant information on delivery of each provider version of the NHS-DDPP. This included content analysis of all delivery documentation listed in Additional file 2 and transcripts of 12 interviews with health coaches, and extracting relevant excerpts into a series of adapted TIDieR checklists. Triangulation was then conducted across these multiple sources of information and results were tabulated. Tables were then reviewed to assess variation across providers and to highlight modifications that had been made to the provider programmes during implementation. The final TIDieR description was checked with the service provider for accuracy. Qualitative interviews of programme developers Participants Interviews were conducted (by LMM and REH) between September and December 2020 with programme developers employed by each of the four digital providers. Programme developers were involved in the design and development of the NHS-DDDP and/or were a key contact at the digital provider best placed to describe how the content was developed for the programme. Interviews with two professionals took place with digital providers 2 and 3, and interviews with one professional took place with digital providers 1 and 4 (n=6 interviews in total). Further details on procedures for informed consent and recruitment are reported elsewhere [17]. Topic guide The interviews were semi-structured and covered a range of topics, including theoretical underpinnings of their programmes, planned behaviour change content and strategies to support engagement; the results of which are published separately [17]. The full topic guide is available in Additional file 4. Interview topics of relevance to the present study included: • The process of developing and/or adapting the NHS-DDPP programme content, including the extent to which the programmes were adapted from any pre-existing digital programmes. • The relationship between the NHS-DDPP with that of the partner face-to-face offering of the programme. • Content of the digital intervention and format of the different intervention features included in the programme. Interviews were conducted by the video call platform Zoom. Recordings were transcribed verbatim. Analysis Transcripts were analysed thematically using Nvivo software (version 12). Full transcripts were reviewed for familiarity and then sections of the interviews relevant to research objective 3 were coded inductively (by LMM). Once all coding was completed, themes were initially generated by LMM. Theme descriptions were then discussed and refined further by all authors. Results Fidelity of design of digital provider programmes compared to service specification Overall fidelity of the structural features of each digital provider’s programme in comparison to those outlined in the NHS service specification (based on providers’ Framework response documents and other supplementary design documentation provided to the research team) was relatively high (Table 1). Duration and frequency of the programme was in line with the requirements of the specification. The ‘mode of delivery’ and ‘materials’ requirements in the service specification were focussed more on the face-to-face format of delivery, and so some variation in how ‘sessions’, materials or content was planned to be delivered digitally is to be expected. Each provider planned to offer ‘support’ to participants and allowed ‘tailoring’, though the mode of delivery of such support and tailoring varied across providers. Routes for measuring participants’ bodyweight and HbA1c were planned for all provider programmes, with the exception of provider 4 that did not refer to HbA1c measurements in its programme plans. [Insert Table 1] Structural features of the delivery of the NHS-DDPP using the adapted TIDieR checklist According to providers’ delivery materials supplied to the research team between July 2020 and August 2022, and content analysis of interviews with health coaches conducted in 2021, programme content across providers is similar in terms of the use of three main categories of content: use of a smartphone app, educational material and support (Table 2). In particular, programme content delivered by a smartphone app was relatively consistent across providers; for example each app had functions to facilitate tracking of behaviours and/or outcomes. [Insert Table 2] Most importantly, there was wide variation in delivery of ‘support’ across providers, in terms of type (1-1 health coaching and/or group support) and for each type, further variation across delivery channel and method, and dose and scheduling. This highlights considerable variation in the intensity of coaching and support delivered to participants across providers. Provider 4’s health coaches are available to provide support reactively to participant questions and predominantly by online chat. In contrast, health coaches from providers 2 and 3 deliver initial consultations by telephone or video call for at least 30 minutes followed by a series of scheduled telephone calls (provider 3) or video messages (provider 2) over 9 months. Provider 1’s health coach support is predominantly offered in a group chat setting, and is proactively delivered by a health coach to the group (though private 1-1 chat also available) up to week 24 of the programme. Group support was offered by three of the four providers during the period of data collection for this study. Again, variation was apparent in the delivery method across providers: two providers offered a group discussion forum (similar to Facebook) and one offered a closed group chat (similar to Whatsapp) and there was variation in the length of time (if any) health coaches were available to moderate such groups. There were further differences in the structural features of the programme across the four providers, in relation to deliverers of the programme (health coaches) and delivery channels/routes used by providers for educational material. The background of health coaches was consistent across providers 1-3, where they usually had at least degree level qualifications in a health-related subject, but health coaches from provider 4 did not have this. To supply educational material, providers used a range of structured e-learning modules, emails, PDFs and workbooks, though on the whole the delivery channel was always passive (a one-way communication from provider to participant). Dose and scheduling of such information across the 9 months of the programme also varied widely. A number of modifications to the provider programmes were identified (Table 2) including the introduction of a new choice of participant pathways for provider 3 in July 2021. This change included the introduction of an option for group support. Each of the four providers’ documentation referred to some degree of updated or review of materials or procedures, particularly for their educational materials, thereby showing that their portfolio of materials and procedures is not static. Qualitative interviews with programme developers Two overarching themes were identified in the thematic analysis, which directly address research objective 3. Theme 1) Adaptation of pre-existing programmes to meet NHS service specification requirements , is broken down into three sub-themes that provide further explanation of the journey from pre-existing programmes to current versions of the NHS-DDPP. Theme 2) Continuous development driven by user experiences directly addresses why changes were made to NHS-DDPP following implementation. Theme 1: Adaptation of pre-existing programmes to meet NHS service specification requirements Across interviews with all providers, it was clear that provider versions of the NHS-DDPP were not purpose-built from scratch. Each provider already had established experience in delivering digital healthcare interventions and had a pre-existing programme or programmes that could be adapted to meet the needs of the NHS service specification. For 3 out of 4 providers, such original programmes were usually a consumer-facing programme designed to help people lose weight and/or change health and wellbeing behaviours. These pre-existing programmes were then adapted in line with the specification, with key adaptations including adding material on prevention of T2DM and/or lengthening the programme. These were often described as ‘tweaks’ or additions rather than redesigns of a programme. “What we kind of had to tweak really was that the NDPP was a bit more structured to what we offered because before we were very much a one-to-one personal coaching service, and every individual service would contain completely different information (Provider 2).” “potentially we’re offering, obviously the usual service with additional curriculum. So when we get other people involved it’s far more from a point of view of how do we provide access codes to individuals rather than, let’s write a digital service for DPP… So when you’re asking for what our other – what other people inputted into it, for us it’s like we’ve got it, we need to adapt it for DPP but we’re not creating something new (Provider 4) .” Sub-theme 1.1 Maintenance of ethos of original programmes Furthermore, the ethos of the original programme was maintained in the NHS-DDPP programmes: “yeah, we haven’t lost that initial, um, framework and philosophy, we’ve really just adapted it to fit the specification of what the commissioners have required (Provider 1)”. The original ethos varied across providers (1, 2 and 4), including a focus on changing health and wellbeing behaviours, personal coaching targeting such behaviours and/or weight loss. Sub-theme 1.2: Relationship with face-face NHS-DPP programme Providers of the NHS-DDPP are subcontracted by providers of the face-face DPP, with the exception of Provider 4 that delivers both digital and face-face versions of the DPP. Therefore the relationship with face-face providers was explored in the interviews, in terms of any influence on development of the NHS-DDPP. Responses were very mixed and varied across providers. Some digital providers described the development of their programme as completely independent of their face-face provider partner, for example: “they didn’t have a huge amount of involvement in our product development I would say. We were given the specification of course, from the invitation to tender. But it was basically up to us to justify how we were going to meet that (Provider 1)”. Provider 3 described some consultation with face-face partners about programme curriculum: “I suppose when they displayed what topics they’d cover in each of their thirteen sessions, and we then equally displayed what we cover, actually we realised they were very similar in content wise and respects (Provider 3)”. Interviewees from providers 2 and 4 viewed the face-face and digital versions of the NHS-DPP as well integrated, particularly because participants in the face-face versions of the NHS-DPP also had access the DDPP apps. Sub-theme 1.3: Evolution from pilot version of DDPP For those providers involved in the pilot study of the NHS-DDPP, experiences from the pilot study were an additional influence on the development of the version of NHS-DDPP implemented in Framework 2. For providers 1 and 2, this was viewed as an additional stage in the adaptation of a consumer-facing programme to the current version of the NHS-DDPP: “So that’s – it’s developed – the intervention that we originally developed has evolved from a twelve-week programme to a six-month programme and to now a nine-month programme. And that’s the programme that we deliver to consumers and then adapting it to the digital pilot of the DPP and now, obviously, the current framework. So all of the different things that were on the specification that we needed to deliver on, and we had to adapt the intervention to make sure that we accommodated those and stood the best chance of winning a place in the framework (Provider 1).” “it was mainly a case of kind of tweaking and localising the content of the delivery model to the UK of which the digital Diabetes Prevention Programme pilot was an initial framework for us to deliver that. Which was then modified based on feedback and tweaks to be the tender of framework for the national Diabetes Prevention Programme (Provider 2)”. However, uniquely for provider 3, their programme was described as developed specifically for the pilot NHS-DDPP, based on experience of other digital health interventions including on digital T2DM management and weight management, and the experiences of the pilot prompted further development: “So for us it was how did we support superior weight loss in the next phase of development with the national pilot. So we, the pathway was definitely adapted from the pilot because actually we could see the engagement worked (Provider 3).” This provider further explained that their experiences of delivering other digital health interventions highlighted the need for intensive support in the early stages of the programme. Theme 2: Continuous development driven by user experiences All providers described a process of continual improvement and development of their digital programmes. In this way, it is clear that any assessment of the NHS-DDPP captures a snapshot in time, as changes are introduced on an ongoing basis: “we’re very proud of our app. It’s something that never stands still. It’s improved all the time (Provider 4)”; “I kind of have to emphasise that we do testing and iteration constantly, on a weekly basis (Provider 1).” These changes are largely driven by user experiences of the programme. Some providers described their own research methods to gain insights on user experiences: “we’re running a trial at the moment to explore group chat function within the app……. So we’ll be doing user interviews and feedback, we’re collecting how many decline that, how many uptake that, and so we’re just trying to gather data now to see actually is that a good offering (Provider 3)”; “we’ve got our own kind [Provider] experience surveys so how patients find the app, what things they find useful, what they find not so useful. Or how they found the coaching, how was their relationship. So we’re constantly developing the app based on user feedback (Provider 2).” Further, in some instances a periodic review of scientific recommendations and guidelines is conducted to ensure that the programme is routinely “up-to-date and evidence-based (Provider 3)”. Discussion Principal findings Our fidelity analysis of the NHS-DDPP shows provider plans for the programmes are generally in line with the NHS service specification. Important variation in programme features has been identified across the four digital providers, as well as modifications to the programmes since implementation. Important differences were identified in terms of support offered to participants (through health coaching and/or group support) and the delivery channels/methods and dose and scheduling by which such support was offered to participants. This results in substantial variation in intensity or support offered to participants across the four digital provider programmes Interviews with programme developers provided rationale and background to why such variation is apparent. For at least 3 out of 4 provider programmes, the origin was a pre-existing programme that was adapted to become in line with the NHS service specification for the DDPP, and much of the ethos of the original programme remained intact. Therefore features of the programmes related to ‘support’ were more a reflection of the original programmes than what was required in the NHS service specification. As subcontractors of face-to-face providers of the DPP, these original pre-existing programmes were usually consumer-facing digital programmes and not specifically related to the face-to-face version of the DPP. Uniquely for provider 3, its programme was described as developed specifically for the pilot DDPP, based on experience of other digital health interventions; such experience highlighted the need for intensive support in the early stages of the programme. Interviews also identified that the digital programmes are continually improved and developed based on user experience feedback and research conducted by providers. Interviews with developers from provider 3 indicated that the option for group support was introduced after the provider had run its own research to explore user experience of group support. Strengths and limitations All documentation supplied by providers (including transcripts of interviews with health coaches) has been reviewed systematically using a standardised TIDieR checklist. Our decision to adapt the TIDieR checklist for describing the delivery of the digital programme is in line with previous research [27] that suggested TIDieR could not capture the full complexity of an online structured education programme for T2DM. The adaptations to the TIDieR checklist to facilitate detailed description of features of digital delivery is an important innovation that could be used again in future studies, and in itself could inform future iterations of TIDieR for use in describing digital health interventions. By using a mixed methods study design, qualitative data from programme developers has been used to provide important background and context to explain the findings from the document review. However, it should be noted that participants who were interviewed for this study were not always necessarily directly involved in the development of the provider programmes. It is possible that some people involved in the early stages of design and development had since moved on to other roles. Nonetheless, the research team tried to identify at least one relevant individual from each digital provider and aimed to interview professionals from different backgrounds to gather a range of views and provide a comprehensive understanding of the processes involved in the design and development of each NHS-DDPP intervention. Every effort was made by the research team to obtain access to all relevant documentation for the study but it is possible that we were not given access to all relevant design and delivery documentation by providers (for example we were not provided with the app for provider 3). Content analysis of interviews with health coaches (as key deliverers of the programme) was included in this study to help to fill any potential gaps in information on provider programmes. By conducting triangulation across multiple sources of information in this way, we can be more confident of the overall picture in results. Relationship with other literature Our finding that provider programmes were designed with relatively high fidelity to the NHS service specification is comparable to outputs from an evaluation of the face-to-face version of the NHS-DPP. The NHS-DPP programme design demonstrated good fidelity to the structural features itemised in the programme specification [22]. A similar evaluation of the pilot NHS Low Calorie Diet Programme (which aims to achieve T2DM remission), which is also delivered by multiple providers working to a single service specification, demonstrated relatively good fidelity to the service parameters stipulated in the NHSE specification [28]. The resulting variation in service delivery across providers that is highlighted in this study is significant, particularly because a substantial component of the variation is around features of the programme that provide support to participants. Programmes did have fidelity to the service specification because the NHS specification documentation simply refers to ‘consider social and psychological support needed to support people to implement behaviour changes and to provide individual 1-1 support’ [12] and is not prescriptive about the format of delivery of support or its dose or scheduling over 9 months. This is notable as prior research [29] suggests that the variation in intensity of support offered to participants could be important. In this systematic review of internet-based interventions to promote health behaviour change, effectiveness was enhanced by the use of additional methods of communicating with participants such as: access to an advisor to request advice, scheduled contact with advisor, and peer-to-peer access (eg, peer-to-peer forums or live chat). Accordingly, one might speculate that the exact intensity, quality and nature of support offered to NHS-DDPP participants could be an important factor in its effectiveness. This is also in line with recent findings from a qualitative study of NHS-DDPP participants [19] that concluded that support from health coaches is very much valued and is furthermore instrumental in helping participants understand and use key behaviour change content in the programme. It has also been suggested that professional support features (such as remote contact with a clinician) can positively influence engagement with digital behavioural interventions [30]. To the authors’ knowledge, the concept of repurposing or adapting a pre-existing intervention to meet a service specification, has not been previously evaluated in the literature. Accordingly, there is some degree of uncertainty regarding the implications of this. Knowledge of this route of programme development could, to some extent, explain the lack of theoretical underpinning for the programme demonstrated previously [17]. In a situation where pre-existing programmes are adapted to meet a service specification, even if there is clear theoretical basis for the pre-existing programme, there is a risk of lack of clarity about how the programme is expected to work when the end purpose of the programme changes to meet a specification (for example from personal health coaching to T2DM prevention). As previously discussed [17], this lack of clarity risks effective translation of behaviour change content in intervention design to intervention delivery. Our finding that shows the NHS-DDPP is continually updated and reviewed by providers, based on user feedback, is positive. An expert consensus [31] has highlighted the need for a user-centred and iterative approach to development of digital interventions, to progressively refine the intervention to meet user requirements. Nevertheless, there is potential for drift in service delivery of this national programme, based only on the needs of active users of the programme rather than taking account of the needs of people who have difficulty taking up and engaging with the NHS-DDPP. Implications for research An immediate question for future research is understanding whether the variation in delivery of the NHS-DDPP across providers is related to any differences in health outcomes (HbA1C and/or weight loss). It would be helpful to know whether participants who receive more support through the programme are more likely to achieve behaviour change and prevention of T2DM, and whether there are particular population groups that benefit most from this support. To date, we are not aware of any analyses of the effectiveness of the implemented NHS-DDPP that report health outcomes according to providers. Experiences from an analysis of the face-to-face DPP lend support to this premise, as large differences in health outcomes were reported across providers, and such variation was found to be a more important factor on outcomes than variation in patient characteristics [8]. Implications for practice This work has potential implications for the NHS-DDPP and the way in which the service is commissioned. NHSE appear to have used a pragmatic approach to implement the NHS-DDPP at pace and at scale, using multiple independent providers to deliver the service. Providers’ approach of adapting pre-existing programmes to meet the NHS-DDPP specification has advantages in terms of meeting a service need efficiently. Recent findings suggest that the face-to-face version of the programme achieves a reduction in population incidence of T2DM [32] and that a digital version of the service can be just as effective [11]. It could be argued that a benefit of this commissioning model is the opportunity to harness expertise already developed by commercial providers, for example around experiences in delivering health coaching. Continuing with this model for commissioning the service allows innovation from commercial providers to be capitalised upon. Notwithstanding this success, there is room for improvement in commissioning of future rounds of the service. It is recommended that future rounds of commissioning include clearer specifications for the type of support participants should receive and detail about the expected dose and scheduling of this support. We acknowledge the potential for tension between supporting fidelity of the national programme with a rigid service specification versus the need for flexibility to allow continual improvement of the programmes through user feedback, and suggest programmes are continually monitored to identify any significant drift in service delivery. The research team continue to share findings from this programme of research with NHSE and a number of improvements have already been made [18]. Conclusions Provider plans for the NHS-DDPP show relatively high fidelity to the NHS service specification. Despite this, there was wide variation in structural features of delivery of the NHS-DDPP across providers. This was most evident for delivery of ‘support’, in terms of use of health coaching and/or group support, with further variation across delivery channel and method, and dose and scheduling. Interviews with developers of the provider programmes showed that much of this variation is likely to be attributable to the ways in which the provider programmes were developed. The origin of each provider’s programme was usually a pre-existing programme that was adapted to become in line with the NHS service specification for the DDPP, and much of the ethos of the original programmes remained intact. Each provider version of the NHS-DDPP is continually improved and developed based on user experience feedback and research conducted by the providers. Abbreviations BCT Behaviour change technique DDPP Digital Diabetes Prevention Programme HbA1c Glycated haemoglobin (used as a measure of blood sugar levels over several months). HC Health Coach NHS National Health Service NHSE National Health Service England NICE National Institute of Health and Care Excellence TIDieR Template for Intervention Description and Replication T2DM Type 2 Diabetes Mellitus Declarations Ethics approval and consent to participate This study was performed in accordance with the Declaration of Helsinki and approved by the North West Greater Manchester East NHS Research Ethics Committee (Reference: 17/NW/0426, 1 st August 2017) as part of a wider programme of research. Full informed consent was obtained verbally from all participants included in this study. Consent procedures for this study were approved by North West Greater Manchester East NHS Research Ethics Committee (Reference: 17/NW/0426, 1 st August 2017). Consent for publication Not applicable Availability of data and materials The materials from digital providers and audio-recordings of interviews analysed in the current study are not publicly available due to confidentiality agreements with the provider organisations, as some information is commercially sensitive. Some datasets are available from the corresponding author on reasonable request, although authors will require the explicit permission of the relevant provider organisations. Competing interests The authors declare that they have no competing interests (review if other authors added). Funding This work is independent research funded by the National Institute for Health and Care Research (Health Services and Delivery Research, 16/48/07 – Evaluating the NHS Diabetes Prevention Programme (NHS DPP): the DIPLOMA research programme (Diabetes Prevention – Long Term Multimethod Assessment)). The views and opinions expressed in this manuscript are those of the authors and do not necessarily reflect those of the National Institute for Health and Care Research or the Department of Health and Social Care. Authors' contributions DPF designed the study and secured funding for this research as part of the wider DIPLOMA project. DPF supervised the research conduct and helped prepare the manuscript. LMM further developed design of the study, was in contact with the management teams to obtain documentation from providers, conducted research interviews, adapted TIDieR checklists for digital delivery, coded documentation using TIDieR, conducted the thematic analysis and drafted the manuscript. REH identified key structural features from specification documents, was in contact with the management teams to obtain documentation from providers, conducted research interviews, coded documentation using TIDieR and helped to prepare the manuscript. All authors read and approved the final manuscript. Acknowledgements We would like to thank the NHS-DDPP Programme team and all digital provider programme leads for providing all relevant documentation required for this manuscript. We would also like to express our appreciation to the participants who took part in an interview. With further thanks to the provider programme leads and management staff for helping to organise interviews. We are grateful to members of the DIPLOMA research team (Peter Bower, Jamie Ross and Paul Wilson) who provided comments on earlier drafts of this manuscript. References Gong Q, Zhang P, Wang J, Ma J, An Y, Chen Y, Zhang B, Feng X, Li H, Chen X, et al. Morbidity and mortality after lifestyle intervention for people with impaired glucose tolerance: 30-year results of the Da Qing Diabetes Prevention Outcome Study. The lancet Diabetes & endocrinology. 2019;7(6):452–61. Knowler WC, Barrett-Connor E, Fowler SE, Hamman RF, Lachin JM, Walker EA, Nathan DM. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med. 2002;346(6):393–403. Tuomilehto J, Lindström J, Eriksson JG, Valle TT, Hämäläinen H, Ilanne-Parikka P, Keinänen-Kiukaanniemi S, Laakso M, Louheranta A, Rastas M, et al. Prevention of type 2 diabetes mellitus by changes in lifestyle among subjects with impaired glucose tolerance. N Engl J Med. 2001;344(18):1343–50. Yin J, Kong APS, Chan JCN. Prevention and Care Programs Addressing the Growing Prevalence of Diabetes in China. Curr Diab Rep. 2016;16(12):130–0. Group TDPPR. The Diabetes Prevention Program (DPP): Description of lifestyle intervention. Diabetes Care. 2002;25(12):2165–71. Valabhji J, Barron E, Bradley D, Bakhai C, Fagg J, O’Neill S, Young B, Wareham N, Khunti K, Jebb S, et al. Early Outcomes From the English National Health Service Diabetes Prevention Programme. Diabetes Care. 2020;43(1):152–60. Brunton L, Soiland-Reyes C, Wilson P. Implications for future policy implementation: a qualitative evaluation of the national rollout of a diabetes prevention programme in England . 02 August 2022, PREPRINT (Version 1). Marsden AM, Bower P, Howarth E, Soiland-Reyes C, Sutton M, Cotterill S. 'Finishing the race' - a cohort study of weight and blood glucose change among the first 36,000 patients in a large-scale diabetes prevention programme. Int J Behav Nutr Phys Act. 2022;19(1):7. Howarth E, Bower PJ, Kontopantelis E, Soiland-Reyes C, Meacock R, Whittaker W, Cotterill S. 'Going the distance': an independent cohort study of engagement and dropout among the first 100 000 referrals into a large-scale diabetes prevention program . BMJ open diabetes research & care 2020, 8(2). Uptake and impact of the English National Health Service digital diabetes prevention programme: observational study . BMJ Open Diabetes Research & Care 2022, 10 (3):e002736. Marsden AMHM, Barron E, Ross J, Valabhji J, Murray E, Cotterill S. Comparison of weight change between a diabetes prevention programme delivered face-to-face or by digital methods: an exploratory non-inferiority study with imputation of plausible weight outcomes, under review. Under review. NHS - DPP National Service Specification [https://. Ashra NB, Spong R, Carter P, Davies MJ, Dunkley A, Gillies C, Greaves C, Khunti K, Sutton S, Yates T, et al: A systematic review and meta - analysis assessing the effectiveness of pragmatic lifestyle interventions for the prevention of type 2 diabetes mellitus in routine practice . In. London: Public Health England; 2015. National Institute of Health and Care Excellence. Type 2 diabetes: prevention in people at high risk. National Institute for Health and Care Excellence . In.; 2017. Bellg AJ, Borrelli B, Resnick B, Hecht J, Minicucci DS, Ory M, Ogedegbe G, Orwig D, Ernst D, Czajkowski S. Enhancing treatment fidelity in health behavior change studies: best practices and recommendations from the NIH Behavior Change Consortium. Health psychology: official journal of the Division of Health Psychology American Psychological Association. 2004;23(5):443–51. Borrelli B. The Assessment, Monitoring, and Enhancement of Treatment Fidelity In Public Health Clinical Trials. J Public Health Dent. 2011;71(s1):52-s63. Hawkes RE, Miles LM, French DP. Fidelity to Program Specification of the National Health Service Digital Diabetes Prevention Program Behavior Change Technique Content and Underpinning Theory: Document Analysis. J Med Internet Res. 2022;24(4):e34253. Hawkes RE, Miles LM, Bower P, Cotterill S, French DP. Assessing and ensuring fidelity of the nationally implemented English NHS diabetes prevention programme: lessons learned for the implementation of large-scale behaviour change programmes. Health Psychol Behav Med. 2022;10(1):498–513. Miles LM, Hawkes RE, French D. How is the behaviour change content of a nationally implemented Digital Diabetes Prevention Programme understood and used by participants? A qualitative study of fidelity of receipt and enactment. Under review. Hawkes RE, Miles LM, French D. What behaviour change technique content is offered to service users of the nationally implemented English NHS Digital Diabetes Prevention Programme: Analysis of multiple sources of intervention content Under review. Hoffmann TC, Glasziou PP, Boutron I, Milne R, Perera R, Moher D, Altman DG, Barbour V, Macdonald H, Johnston M, et al. Better reporting of interventions: template for intervention description and replication (TIDieR) checklist and guide. BMJ. 2014;348:g1687. Hawkes RE, Cameron E, Bower P, French DP. Does the design of the NHS Diabetes Prevention Programme intervention have fidelity to the programme specification? A document analysis. Diabet medicine: J Br Diabet Association. 2020;37(8):1357–66. Cotterill S, Knowles S, Martindale A-M, Elvey R, Howard S, Coupe N, Wilson P, Spence M. Getting messier with TIDieR: embracing context and complexity in intervention reporting. BMC Med Res Methodol. 2018;18(1):12. Marques M, Carey R, Norris E, Evans F, Finnerty A, Hastings J, Jenkins E, Johnston M, West R, Michie S. Delivering Behaviour Change Interventions: Development of a Mode of Delivery Ontology [version 2; peer review: 2 approved] . Wellcome Open Research 2021, 5(125). Agarwal S, LeFevre AE, Lee J, L'Engle K, Mehl G, Sinha C, Labrique A. Guidelines for reporting of health interventions using mobile phones: mobile health (mHealth) evidence reporting and assessment (mERA) checklist. BMJ. 2016;352:i1174. Dombrowski SU, O'Carroll RE, Williams B. Form of delivery as a key ‘active ingredient’ in behaviour change interventions. Br J Health Psychol. 2016;21(4):733–40. Poduval S, Ross J, Pal K, Newhouse N, Hamilton F, Murray E. Use of the TIDieR checklist to describe an online structured education programme for type 2 diabetes. Digit health. 2020;6:2055207620975647. Evans TS, Dhir P, Radley D, Duarte C, Keyworth C, Homer C, Hill AJ, Hawkes RE, Matu J, McKenna J, et al: Does the design of the NHS Low Calorie Diet Programme have fidelity to the programme specification? A documentary review of service parameters and behaviour change content. Under review. Webb TL, Joseph J, Yardley L, Michie S. Using the Internet to Promote Health Behavior Change: A Systematic Review and Meta-analysis of the Impact of Theoretical Basis, Use of Behavior Change Techniques, and Mode of Delivery on Efficacy. J Med Internet Res. 2010;12(1):e4. Perski O, Blandford A, West R, Michie S. Conceptualising engagement with digital behaviour change interventions: a systematic review using principles from critical interpretive synthesis. Translational Behav Med. 2017;7(2):254–67. Yardley L, Spring BJ, Riper H, Morrison LG, Crane DH, Curtis K, Merchant GC, Naughton F, Blandford A. Understanding and Promoting Effective Engagement With Digital Behavior Change Interventions. Am J Prev Med. 2016;51(5):833–42. McManus E, Meacock R, Parkinson B, Sutton M. Population level impact of the NHS Diabetes Prevention Programme on incidence of type 2 diabetes in England: An observational study. Lancet Reg health Europe. 2022;19:100420. Tables Tables 1 to 2 are available in the Supplementary Files section Additional Declarations No competing interests reported. Supplementary Files Additionalfile110.10.2022.docx Additionalfile210.10.2022.docx Additionalfile3.07.11.2022.docx Additionalfile410.10.2022.docx Tables.docx Cite Share Download PDF Status: Published Journal Publication published 18 Apr, 2023 Read the published version in BMC Health Services Research → Version 1 posted Editorial decision: Major revision 27 Jan, 2023 Reviews received at journal 25 Jan, 2023 Reviews received at journal 02 Dec, 2022 Reviewers agreed at journal 01 Dec, 2022 Reviewers agreed at journal 22 Nov, 2022 Reviewers invited by journal 21 Nov, 2022 Editor assigned by journal 21 Nov, 2022 Editor invited by journal 07 Nov, 2022 Submission checks completed at journal 07 Nov, 2022 First submitted to journal 10 Oct, 2022 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-2152186","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":150139160,"identity":"9425e575-d822-4e9b-ae26-5e82b2e04e5b","order_by":0,"name":"Lisa M Miles","email":"","orcid":"","institution":"University of Manchester","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Lisa","middleName":"M","lastName":"Miles","suffix":""},{"id":150139161,"identity":"7d7627ff-dbcd-4389-94a5-9aedd7e94bb4","order_by":1,"name":"Rhiannon E Hawkes","email":"","orcid":"","institution":"University of Manchester","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Rhiannon","middleName":"E","lastName":"Hawkes","suffix":""},{"id":150139162,"identity":"0bbacbe6-d68c-4ed2-a813-b531c2d06510","order_by":2,"name":"David P French","email":"data:image/png;base64,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","orcid":"","institution":"University of Manchester","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"David","middleName":"P","lastName":"French","suffix":""}],"badges":[],"createdAt":"2022-10-10 19:14:09","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-2152186/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-2152186/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12913-023-09210-3","type":"published","date":"2023-04-18T20:31:35+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":44726013,"identity":"03e7ff40-18bd-4eb1-af30-62e4c328833c","added_by":"auto","created_at":"2023-10-16 20:45:06","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":790383,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-2152186/v1/ab028b8b-0044-4f7e-9bd5-acb12c5f3c84.pdf"},{"id":28844854,"identity":"64d7ace7-2347-4fff-b9fe-5e8f72a84d2c","added_by":"auto","created_at":"2022-11-09 09:07:32","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":18323,"visible":true,"origin":"","legend":"","description":"","filename":"Additionalfile110.10.2022.docx","url":"https://assets-eu.researchsquare.com/files/rs-2152186/v1/2cdc450c06b8c3d6d4a92c59.docx"},{"id":28845361,"identity":"3c475741-3d99-42cd-972b-95926431b4b2","added_by":"auto","created_at":"2022-11-09 09:23:32","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":26147,"visible":true,"origin":"","legend":"","description":"","filename":"Additionalfile210.10.2022.docx","url":"https://assets-eu.researchsquare.com/files/rs-2152186/v1/81638dd38747117404fc0875.docx"},{"id":28844851,"identity":"d0a2219a-e6aa-4120-8533-6f23902ad9f8","added_by":"auto","created_at":"2022-11-09 09:07:32","extension":"docx","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":32097,"visible":true,"origin":"","legend":"","description":"","filename":"Additionalfile3.07.11.2022.docx","url":"https://assets-eu.researchsquare.com/files/rs-2152186/v1/481a5654713e597fd62b29f9.docx"},{"id":28845213,"identity":"6ad7893b-8103-4ad5-8e2c-ed88195fea3e","added_by":"auto","created_at":"2022-11-09 09:15:32","extension":"docx","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":27447,"visible":true,"origin":"","legend":"","description":"","filename":"Additionalfile410.10.2022.docx","url":"https://assets-eu.researchsquare.com/files/rs-2152186/v1/1cce8cbf7f212d6d11114b4f.docx"},{"id":28844850,"identity":"6164f610-1a27-4fc3-b4e8-6dcc06621e72","added_by":"auto","created_at":"2022-11-09 09:07:32","extension":"docx","order_by":5,"title":"","display":"","copyAsset":false,"role":"supplement","size":43104,"visible":true,"origin":"","legend":"","description":"","filename":"Tables.docx","url":"https://assets-eu.researchsquare.com/files/rs-2152186/v1/a992f212ae0b47e4f416c6db.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Description of the nationally implemented National Health Service Digital Diabetes Prevention Programme intervention and rationale for its development: mixed methods study","fulltext":[{"header":"Background","content":"\u003cp\u003eType 2 diabetes mellitus (T2DM) is a major public health concern that is largely preventable by weight loss and improved diet and physical activity. Following the success of diabetes prevention trials [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], several diabetes prevention programmes have been implemented around the world [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn 2016, the National Health Service (NHS) in England implemented the Healthier You: NHS Diabetes Prevention Programme (NHS-DPP) for adults at risk of developing T2DM. The NHS-DPP is a behaviour change programme delivered in groups which aimed to support participants improve dietary and physical activity behaviours, and prevent progression to T2DM. It has been rolled out in waves, gradually reaching universal national coverage [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Delivery of the NHS-DPP is procured through a national competitive process, organised by NHS England (NHSE); this was originally conducted through a Framework Agreement in 2016 (Framework 1), in which four providers were selected to deliver a face-to-face version of the programme [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eEarly favourable health outcomes from the NHS-DPP have been reported [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], but it has been suggested that measures are needed to improve uptake and retention on the programme for younger people, those in employment, minority ethnic and deprived groups and those reporting a disability [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. A digital version of the NHS-DPP was piloted in 2017/2018; participation in the programme was associated with clinically significant reductions in weight (-3.1kg) and HbA1c (-1.6mmol/mol) at 12 months [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. These changes have been shown to be comparable to those of the face-to-face programme [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe NHS-DPP was then re-procured in 2019, when a number of enhancements were made to the service specification, including the introduction of a digital DPP service as an adjunct to the face-to-face service (Framework 2). At this point, five providers were selected to deliver the face-to-face group service by NHSE to provide NHS DPP across England: four of the previous providers plus one new provider [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Four of these five providers sub-contracted digital providers to deliver the digital service (NHS-DDPP). This resulted in important partnerships between providers of the face-to-face and digital programmes. As part of the competitive process to secure contracts to deliver the programme, face-to-face and digital providers worked together to submit a Framework 2 response describing their proposed service delivery and planned content. During delivery of the service under Framework 2, one digital provider contract ended. The remaining four digital providers are commercial entities.\u003c/p\u003e \u003cp\u003eNHSE produced a Framework 2 service specification [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] detailing the key features that should be present in the NHS-DPP [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] based on the currently available evidence [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. The present research examines the fidelity of each digital providers\u0026rsquo; programme to this specification. Intervention fidelity refers to whether an intervention was designed, delivered and received as planned [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. An assessment of fidelity is important to fully understand the reasons why interventions are effective or not. Without it, reports of an effective intervention could be a function of either an effective intervention or the influence of other unknown factors added to or omitted from the intervention [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Our research team has reported extensively on the fidelity of the behaviour change content of face-to-face and digital versions of the NHS-DPP [\u003cspan additionalcitationids=\"CR18 CR19\" citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn the present study we assess the fidelity of the structural features (such as materials and mode of delivery) of the design of the NHS-DDPP compared to the NHS service specification, and describe the delivery of the NHS-DDPP using the Template for Intervention Description and Replications (TIDieR) checklist [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. The TIDieR checklist has been developed as part of a movement towards standardised reporting of non-pharmacological interventions. Accurate description of interventions is important to facilitate replicability and implementation beyond randomised controlled trials (RCTs).\u003c/p\u003e \u003cp\u003eIn addition to an assessment of fidelity to the service specification, it is also important to fully document the reasons for changes in key structural features of delivery of the NHS-DDPP as it is implemented. Although the programme is commissioned centrally by NHSE and each provider is working to a single service specification, because the programme is delivered by multiple providers, there is potential for some variation in the service across providers. It is important to understand what (if any) variation occurs as the programme is implemented. Further, it is informative to explore the journey by which the provider programmes were developed, to explain how and why the programmes were structured as they are. Such findings can provide important context for further evaluative work on the NHS-DDPP and further inform implementation of the NHS-DPP and other similar programmes.\u003c/p\u003e \u003cp\u003eA mixed methods approach has been chosen to document the structural features of the NHS-DDPP (quantitative) and the evolution of the provider programmes throughout the journey of development and implementation (qualitative). Specifically, the objectives of the present study are firstly to: 1) compare the structural features of the NHS-DDPP design to the NHS service specification for the programme (fidelity); 2) describe the structural features of the delivery of the NHS-DDPP using TIDieR (highlighting variation across providers and any modifications introduced following implementation). Secondly, a series of interviews with NHS-DDPP programme developers has allowed a qualitative assessment of 3) how the structural components of the NHS-DDPP were developed and why changes were made to the programme following implementation.\u003c/p\u003e"},{"header":"Methods","content":"\u003ch3\u003e\u003cstrong\u003eDesign\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eThis study used a mixed-methods design. Components of the NHS-DDPP were content-analysed for structural features of design (objective 1) and delivery (objective 2). Semi-structured interviews investigated how the NHS-DDPP was developed and any rationale for any changes made to the NHS-DDPP once implemented (objective 3).\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDocument review\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003e\u003cstrong\u003eProgramme specification documents\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe programme specification documents for the NHS-DDPP indicate the key content that should be included in the programme, and comprise of the NHS service specification [12] and NICE Guideline PH38 on Type 2 Diabetes: Prevention in People at High Risk [14]. The former was specific to commissioning of the NHS-DPP (including face-to-face and digital offerings in Framework 2 and was based on an evidence review of lifestyle interventions for the prevention of T2DM [13] and drew on recommendations from NICE PH38 guideline [14]. The NICE PH38 guideline provided additional information regarding behaviour change content to be included in diabetes prevention programmes and was referred to in the NHS Service Specification [12]. Key structural features from these specification documents have been identified in a previous study [22] \u0026nbsp;and have been used again here as a basis for assessing fidelity in the current study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDesign materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe design documentation supplied by each digital provider to the research team has been described previously [17]. In brief, this comprises Framework 2 response bids each provider submitted to NHSE (by 15th October 2018), during procurement and supplementary information (further documentation and/or email correspondence) obtained from providers between June 2020 and April 2021.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eAnalysis\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe design of each provider version of the NHS-DDPP was described using the TIDieR checklist [21]. TIDieR items (e.g. materials, procedures, modes of delivery) were extracted by REH from the Framework 2 responses; TIDieR items were later extracted by LMM from supplementary design information from providers. \u0026nbsp;The final TIDieR description was checked with the service provider for accuracy. Results were tabulated and compared with requirements in the NHS specification as an assessment of fidelity.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDelivery materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe delivery documentation provided by each digital provider to the research team has been described previously\u0026nbsp;[20]\u0026nbsp;and is detailed in Additional file 1.\u0026nbsp;This comprised:\u0026nbsp;\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eGuest access to smartphone and web applications for three out of the four providers. The other provider supplied an app user guide.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eAll educational materials, including learning platforms, online articles, PDF articles, videos, online workbooks and additional workbooks posted to service users.\u003c/li\u003e\n \u003cli\u003eStandard text/script sent to service users via email and text messages.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cem\u003eInterviews with health coaches\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eFurther, a series of semi-structured interviews were conducted with health coaches who are actively involved in delivering the NHS-DDPP.\u0026nbsp;A total of two, four, two and four interviews (n = 12) were conducted with health coaches from providers 1, 2, 3 and 4 respectively between July and November 2021.\u0026nbsp;Recruitment and informed consent procedures for health coaches taking part in the interviews are described elsewhere\u0026nbsp;[20]. In brief, interviews were conducted via the video conferencing platform Zoom and\u0026nbsp;covered the following topics of relevance to the present study:\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eParticipants\u0026rsquo; professional background and any training received.\u003c/li\u003e\n \u003cli\u003eParticipants\u0026rsquo; role in supporting service users throughout the programme (e.g. at first contact, continued engagement, coaching via telephone/video calls and/or online chat, moderating support forums).\u003c/li\u003e\n \u003cli\u003eParticipant\u0026rsquo;s role in tailoring or personalising coaching to individuals.\u003c/li\u003e\n \u003cli\u003eContent of the digital intervention, including the format of intervention features included in the programme and any modifications that have been made.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eThe full topic guide for the interviews is available in Additional file 2.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eAnalysis\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eAlthough the TIDieR checklist [21] has been found to be a useful tool for applied health research studies [23], it was originally developed before the rapid growth in availability and application of \u003cem\u003edigital\u003c/em\u003e health interventions. We therefore considered recent literature relevant to describing digital health interventions [24-26] and adapted the items in the TIDieR checklist to better reflect description of a nationally implemented digital health intervention (NHS-DDPP). Specifically, items 6 (\u0026lsquo;how\u0026rsquo;), 8 (\u0026lsquo;when and how much\u0026rsquo;) and 9 (\u0026lsquo;tailoring\u0026rsquo;) have had sub- items added to carefully describe format of delivery, details of scheduling of different procedures (information sessions and health coaching) and nature of tailoring,. These changes are largely built on a framework for form of delivery (which includes all features through which behaviour change intervention content is conveyed including: the provider, format, materials, setting, intensity, tailoring, and style) [26] and informed by important aspects of delivery highlighted in an ontology for specifying the mode of delivery of interventions [24] (namely, adding\u0026rsquo; interactivity\u0026rsquo;). In addition, we acted on a recommendation [23] to include a column in the TIDieR checklist for \u0026lsquo;modifications\u0026rsquo;, so that changes to the programme since implementation could be captured (see Additional file 3 for adapted TIDieR checklist). Further, we decided to not report rationale, theory and goals of the NHS-DDPP from item 2 of the TIDieR checklist (\u0026lsquo;why\u0026rsquo;) in the current study, as this has already been reported in previous work by the research team regarding theoretical underpinnings of the NHS-DDPP [17].\u003c/p\u003e\n\u003cp\u003eThe adapted TIDieR checklist was used by LMM and REH to extract relevant information on delivery of each provider version of the NHS-DDPP. This included content analysis of all delivery documentation listed in Additional file 2 and transcripts of 12 interviews with health coaches, and extracting relevant excerpts into a series of adapted TIDieR checklists.\u0026nbsp;Triangulation was then conducted across these multiple sources of information and results were tabulated. Tables were then reviewed to assess variation across providers and to highlight modifications that had been made to the provider programmes during implementation. The final TIDieR description was checked with the service provider for accuracy.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003cstrong\u003eQualitative interviews of programme developers\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eParticipants\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eInterviews were conducted (by LMM and REH) between September and December 2020 with programme developers employed by each of the four digital providers. Programme developers were involved in the design and development of the NHS-DDDP and/or were a key contact at the digital provider best placed to describe how the content was developed for the programme. Interviews with two professionals took place with digital providers 2 and 3, and interviews with one professional took place with digital providers 1 and 4 (n=6 interviews in total). Further details on procedures for informed consent and recruitment are reported elsewhere\u0026nbsp;[17].\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003cstrong\u003eTopic guide\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe interviews were semi-structured and covered a range of topics, including theoretical underpinnings of their programmes, planned behaviour change content and strategies to support engagement; the results of which are published separately\u0026nbsp;[17]. The full topic guide is available in\u0026nbsp;Additional file\u0026nbsp;4. Interview topics of relevance to the present study included:\u003c/p\u003e\n\u003cp\u003e\u0026bull; The\u0026nbsp;process of developing and/or adapting the\u0026nbsp;NHS-DDPP\u0026nbsp;programme content, including the extent to which the programmes were adapted from any pre-existing digital programmes.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026bull; The relationship between the NHS-DDPP with that of the partner face-to-face offering of the programme.\u003c/p\u003e\n\u003cp\u003e\u0026bull; Content of the digital intervention and format of the different intervention features included in the programme.\u003c/p\u003e\n\u003cp\u003eInterviews were conducted by the video call platform Zoom. Recordings were transcribed verbatim.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAnalysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTranscripts were analysed thematically using Nvivo software (version 12). Full transcripts were reviewed for familiarity and then sections of the interviews relevant to research objective 3 were coded inductively (by LMM). Once all coding was completed, themes were initially generated by LMM. \u0026nbsp;Theme descriptions were then discussed and refined further by all authors.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eFidelity of design of digital provider programmes compared to service specification\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOverall fidelity of the structural features of each digital provider’s programme in comparison to those outlined in the NHS service specification (based on providers’ Framework response documents and other supplementary design documentation provided to the research team) was relatively high (Table 1). Duration and frequency of the programme was in line with the requirements of the specification. The ‘mode of delivery’ and ‘materials’ requirements in the service specification were focussed more on the face-to-face format of delivery, and so some variation in how ‘sessions’, materials or content was planned to be delivered digitally is to be expected. Each provider planned to offer ‘support’ to participants and allowed ‘tailoring’, though the mode of delivery of such support and tailoring varied across providers. Routes for measuring participants’ bodyweight and HbA1c were planned for all provider programmes, with the exception of provider 4 that did not refer to HbA1c measurements in its programme plans.\u003c/p\u003e\n\u003cp\u003e[Insert Table 1]\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStructural features of the delivery of the NHS-DDPP using the adapted TIDieR checklist\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAccording to providers’ delivery materials supplied to the research team between July 2020 and August 2022, and content analysis of interviews with health coaches conducted in 2021, programme content across providers is similar in terms of the use of three main categories of content: use of a smartphone app, educational material and support (Table 2). In particular, programme content delivered by a smartphone app was relatively consistent across providers; for example each app had functions to facilitate tracking of behaviours and/or outcomes.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e[Insert Table 2]\u003c/p\u003e\n\u003cp\u003eMost importantly, there was wide variation in delivery of ‘support’ across providers, in terms of type (1-1 health coaching and/or group support) and for each type, further variation across delivery channel and method, and dose and scheduling. This highlights considerable variation in the intensity of coaching and support delivered to participants across providers. Provider 4’s health coaches are available to provide support reactively to participant questions and predominantly by online chat. In contrast, health coaches from providers 2 and 3 deliver initial consultations by telephone or video call for at least 30 minutes followed by a series of scheduled telephone calls (provider 3) or video messages (provider 2) over 9 months. Provider 1’s health coach support is predominantly offered in a group chat setting, and is proactively delivered by a health coach to the group (though private 1-1 chat also available) up to week 24 of the programme.\u003c/p\u003e\n\u003cp\u003eGroup support was offered by three of the four providers during the period of data collection for this study. Again, variation was apparent in the delivery method across providers: two providers offered a group discussion forum (similar to Facebook) and one offered a closed group chat (similar to Whatsapp) and there was variation in the length of time (if any) health coaches were available to moderate such groups.\u003c/p\u003e\n\u003cp\u003eThere were further differences in the structural features of the programme across the four providers, in relation to deliverers of the programme (health coaches) and delivery channels/routes used by providers for educational material. The background of health coaches was consistent across providers 1-3, where they usually had at least degree level qualifications in a health-related subject, but health coaches from provider 4 did not have this.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTo supply educational material, providers used a range of structured e-learning modules, emails, PDFs and workbooks, though on the whole the delivery channel was always passive (a one-way communication from provider to participant). Dose and scheduling of such information across the 9 months of the programme also varied widely.\u003c/p\u003e\n\u003cp\u003eA number of modifications to the provider programmes were identified (Table 2) including the introduction of a new choice of participant pathways for provider 3 in July 2021. This change included the introduction of an option for group support. Each of the four providers’ documentation referred to some degree of updated or review of materials or procedures, particularly for their educational materials, thereby showing that their portfolio of materials and procedures is not static.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eQualitative interviews with programme developers\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTwo overarching themes were identified in the thematic analysis, which directly address research objective 3. Theme 1) \u003cem\u003eAdaptation of pre-existing programmes to meet NHS service specification requirements\u003c/em\u003e, is broken down into three sub-themes that provide further explanation of the journey from pre-existing programmes to current versions of the NHS-DDPP. Theme 2) \u003cem\u003eContinuous development driven by user experiences\u003c/em\u003e directly addresses why changes were made to NHS-DDPP following implementation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTheme 1: Adaptation of pre-existing programmes to meet NHS service specification requirements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAcross interviews with all providers, it was clear that provider versions of the NHS-DDPP were not purpose-built from scratch. Each provider already had established experience in delivering digital healthcare interventions and had a pre-existing programme or programmes that could be adapted to meet the needs of the NHS service specification. For 3 out of 4 providers, such original programmes were usually a consumer-facing programme designed to help people lose weight and/or change health and wellbeing behaviours. These pre-existing programmes were then adapted in line with the specification, with key adaptations including adding material on prevention of T2DM and/or lengthening the programme. These were often described as ‘tweaks’ or additions rather than redesigns of a programme.\u003c/p\u003e\n\u003cp\u003e“What we kind of had to tweak really was that the NDPP was a bit more structured to what we offered because before we were very much a one-to-one personal coaching service, and every individual service would contain completely different information (Provider 2).”\u003c/p\u003e\n\u003cp\u003e“potentially we’re offering, obviously the usual service with additional curriculum. \u0026nbsp;So when we get other people involved it’s far more from a point of view of how do we provide access codes to individuals rather than, let’s write a digital service for DPP… \u0026nbsp;So when you’re asking for what our other – what other people inputted into it, for us it’s like we’ve got it, we need to adapt it for DPP but we’re not creating something new (Provider 4) .”\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSub-theme 1.1 Maintenance of ethos of original programmes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFurthermore, the ethos of the original programme was maintained in the NHS-DDPP programmes: \u0026nbsp;“yeah, we haven’t lost that initial, um, framework and philosophy, we’ve really just adapted it to fit the specification of what the commissioners have required (Provider 1)”. The original ethos varied across providers (1, 2 and 4), including a focus on changing health and wellbeing behaviours, personal coaching targeting such behaviours and/or weight loss.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSub-theme 1.2: Relationship with face-face NHS-DPP programme\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eProviders of the NHS-DDPP are subcontracted by providers of the face-face DPP, with the exception of Provider 4 that delivers both digital and face-face versions of the DPP. Therefore the relationship with face-face providers was explored in the interviews, in terms of any influence on development of the NHS-DDPP. Responses were very mixed and varied across providers. Some digital providers described the development of their programme as completely independent of their face-face provider partner, for example:\u003c/p\u003e\n\u003cp\u003e“they didn’t have a huge amount of involvement in our product development I would say. \u0026nbsp;We were given the specification of course, from the invitation to tender. \u0026nbsp; But it was basically up to us to justify how we were going to meet that (Provider 1)”.\u003c/p\u003e\n\u003cp\u003eProvider 3 described some consultation with face-face partners about programme curriculum: “I suppose when they displayed what topics they’d cover in each of their thirteen sessions, and we then equally displayed what we cover, actually we realised they were very similar in content wise and respects (Provider 3)”.\u003c/p\u003e\n\u003cp\u003eInterviewees from providers 2 and 4 viewed the face-face and digital versions of the NHS-DPP as well integrated, particularly because participants in the face-face versions of the NHS-DPP also had access the DDPP apps.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSub-theme 1.3: Evolution from pilot version of DDPP\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFor those providers involved in the pilot study of the NHS-DDPP, experiences from the pilot study were an additional influence on the development of the version of NHS-DDPP implemented in Framework 2. For providers 1 and 2, this was viewed as an additional stage in the adaptation of a consumer-facing programme to the current version of the NHS-DDPP:\u003c/p\u003e\n\u003cp\u003e“So that’s – it’s developed – the intervention that we originally developed has evolved from a twelve-week programme to a six-month programme and to now a nine-month programme. \u0026nbsp;And that’s the programme that we deliver to consumers and then adapting it to the digital pilot of the DPP and now, obviously, the current framework. \u0026nbsp;So all of the different things that were on the specification that we needed to deliver on, and we had to adapt the intervention to make sure that we accommodated those and stood the best chance of winning a place in the framework (Provider 1).”\u003c/p\u003e\n\u003cp\u003e“it was mainly a case of kind of tweaking and localising the content of the delivery model to the UK of which the digital Diabetes Prevention Programme pilot was an initial framework for us to deliver that. \u0026nbsp; Which was then modified based on feedback and tweaks to be the tender of framework for the national Diabetes Prevention Programme (Provider 2)”.\u003c/p\u003e\n\u003cp\u003eHowever, uniquely for provider 3, their programme was described as developed specifically for the pilot NHS-DDPP, based on experience of other digital health interventions including on digital T2DM management and weight management, and the experiences of the pilot prompted further development: “So for us it was how did we support superior weight loss in the next phase of development with the national pilot. \u0026nbsp;So we, the pathway was definitely adapted from the pilot because actually we could see the engagement worked (Provider 3).” This provider further explained that their experiences of delivering other digital health interventions highlighted the need for intensive support in the early stages of the programme.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTheme 2: Continuous development driven by user experiences\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll providers described a process of continual improvement and development of their digital programmes. In this way, it is clear that any assessment of the NHS-DDPP captures a snapshot in time, as changes are introduced on an ongoing basis: “we’re very proud of our app. \u0026nbsp;It’s something that never stands still. \u0026nbsp;It’s improved all the time (Provider 4)”; “I kind of have to emphasise that we do testing and iteration constantly, on a weekly basis (Provider 1).”\u003c/p\u003e\n\u003cp\u003eThese changes are largely driven by user experiences of the programme. Some providers described their own research methods to gain insights on user experiences: “we’re running a trial at the moment to explore group chat function within the app……. So we’ll be doing user interviews and feedback, we’re collecting how many decline that, how many uptake that, and so we’re just trying to gather data now to see actually is that a good offering (Provider 3)”; “we’ve got our own kind [Provider] experience surveys so how patients find the app, what things they find useful, what they find not so useful. \u0026nbsp; Or how they found the coaching, how was their relationship. \u0026nbsp;So we’re constantly developing the app based on user feedback (Provider 2).” Further, in some instances a periodic review of scientific recommendations and guidelines is conducted to ensure that the programme is routinely “up-to-date and evidence-based (Provider 3)”.\u003c/p\u003e"},{"header":"Discussion","content":"\u003ch3\u003e\u003cstrong\u003ePrincipal findings\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eOur fidelity analysis of the NHS-DDPP shows provider plans for the programmes are generally in line with the NHS service specification. Important variation in programme features has been identified across the four digital providers, as well as modifications to the programmes since implementation. Important differences were identified in terms of support offered to participants (through health coaching and/or group support) and the delivery channels/methods and dose and scheduling by which such support was offered to participants. This results in substantial variation in intensity or support offered to participants across the four digital provider programmes\u003c/p\u003e\n\u003cp\u003eInterviews with programme developers provided rationale and background to why such variation is apparent. For at least 3 out of 4 provider programmes, the origin was a pre-existing programme that was adapted to become in line with the NHS service specification for the DDPP, and much of the ethos of the original programme remained intact. Therefore features of the programmes related to ‘support’ were more a reflection of the original programmes than what was required in the NHS service specification. \u0026nbsp;As subcontractors of face-to-face providers of the DPP, these original pre-existing programmes were usually consumer-facing digital programmes and not specifically related to the face-to-face version of the DPP. Uniquely for provider 3, its programme was described as developed specifically for the pilot DDPP, based on experience of other digital health interventions; such experience highlighted the need for intensive support in the early stages of the programme.\u003c/p\u003e\n\u003cp\u003eInterviews also identified that the digital programmes are continually improved and developed based on user experience feedback and research conducted by providers. Interviews with developers from provider 3 indicated that the option for group support was introduced after the provider had run its own research to explore user experience of group support.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eStrengths and limitations\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eAll documentation supplied by providers (including transcripts of interviews with health coaches) has been reviewed systematically using a standardised TIDieR checklist. Our decision to adapt the TIDieR checklist for describing the delivery of the digital programme is in line with previous research\u0026nbsp;[27]\u0026nbsp;that suggested TIDieR could not capture the full complexity of an online structured education programme for T2DM. The adaptations to the TIDieR checklist to facilitate detailed description of features of digital delivery is an important innovation that could be used again in future studies, and in itself could inform future iterations of TIDieR for use in describing digital health interventions. By using a mixed methods study design, qualitative data from programme developers has been used to provide important background and context to explain the findings from the document review.\u003c/p\u003e\n\u003cp\u003eHowever, it should be noted that participants who were interviewed for this study were not always necessarily directly involved in the development of the provider programmes. It is possible that some people involved in the early stages of design and development had since moved on to other roles. Nonetheless, the research team tried to identify at least one relevant individual from each digital provider and aimed to interview professionals from different backgrounds to gather a range of views and provide a comprehensive understanding of the processes involved in the design and development of each NHS-DDPP intervention. Every effort was made by the research team to obtain access to all relevant documentation for the study but it is possible that we were not given access to all relevant design and delivery documentation by providers (for example we were not provided with the app for provider 3). Content analysis of interviews with health coaches (as key deliverers of the programme) was included in this study to help to fill any potential gaps in information on provider programmes. By conducting triangulation across multiple sources of information in this way, we can be more confident of the overall picture in results.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRelationship with other literature\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOur finding that provider programmes were designed with relatively high fidelity to the NHS service specification is comparable to outputs from an evaluation of the face-to-face version of the NHS-DPP. \u0026nbsp;The NHS-DPP programme design demonstrated good fidelity to the structural features itemised in the programme specification\u0026nbsp;[22]. A similar evaluation of the pilot NHS Low Calorie Diet Programme (which aims to achieve T2DM remission), which is also delivered by multiple providers working to a single service specification, demonstrated relatively good fidelity to the service parameters stipulated in the NHSE specification\u0026nbsp;[28].\u003c/p\u003e\n\u003cp\u003eThe resulting variation in service delivery across providers that is highlighted in this study is significant, particularly because a substantial component of the variation is around features of the programme that provide support to participants. Programmes did have fidelity to the service specification because the NHS specification documentation simply refers to ‘consider social and psychological support needed to support people to implement behaviour changes and to provide individual 1-1 support’\u0026nbsp;[12]\u0026nbsp;and is not prescriptive about the format of delivery of support or its dose or scheduling over 9 months. This is notable as prior research\u0026nbsp;[29]\u0026nbsp;suggests that the variation in intensity of support offered to participants could be important.\u0026nbsp;In this systematic review of internet-based interventions to promote health behaviour change,\u0026nbsp;effectiveness was enhanced by the use of additional methods of communicating with participants such as: access to an advisor to request advice, scheduled contact with advisor, and peer-to-peer access (eg, peer-to-peer forums or live chat). Accordingly, one might speculate that the exact intensity, quality and nature of support offered to NHS-DDPP participants could be an important factor in its effectiveness. This is also in line with recent findings from a qualitative study of NHS-DDPP participants\u0026nbsp;[19]\u0026nbsp;that concluded that support from health coaches is very much valued and is furthermore instrumental in helping participants understand and use key behaviour change content in the programme. It has also been suggested that\u0026nbsp;professional support features (such as remote contact with a clinician) can positively influence engagement with digital behavioural interventions\u0026nbsp;[30].\u003c/p\u003e\n\u003cp\u003eTo the authors’ knowledge, the concept of repurposing or adapting a pre-existing intervention to meet a service specification, has not been previously evaluated in the literature. Accordingly, there is some degree of uncertainty regarding the implications of this. Knowledge of this route of programme development could, to some extent, explain the lack of theoretical underpinning for the programme demonstrated previously\u0026nbsp;[17]. In a situation where pre-existing programmes are adapted to meet a service specification, even if there is clear theoretical basis for the pre-existing programme, there is a risk of lack of clarity about how the programme is expected to work when the end purpose of the programme changes to meet a specification (for example from personal health coaching to T2DM prevention). As previously discussed\u0026nbsp;[17], this lack of clarity risks effective translation of behaviour change content in intervention design to intervention delivery.\u003c/p\u003e\n\u003cp\u003eOur finding that shows the NHS-DDPP is continually updated and reviewed by providers, based on user feedback, is positive. An expert consensus\u0026nbsp;[31]\u0026nbsp;has highlighted the need for a user-centred and iterative approach to development of digital interventions, to progressively refine the intervention to meet user requirements. Nevertheless, there is potential for drift in service delivery of this national programme, based only on the needs of active users of the programme rather than taking account of the needs of people who have difficulty taking up and engaging with the NHS-DDPP.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eImplications for research\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAn immediate question for future research is understanding whether the variation in delivery of the NHS-DDPP across providers is related to any differences in health outcomes (HbA1C and/or weight loss). It would be helpful to know whether participants who receive more support through the programme are more likely to achieve behaviour change and prevention of T2DM, and whether there are particular population groups that benefit most from this support. To date, we are not aware of any analyses of the effectiveness of the implemented NHS-DDPP that report health outcomes according to providers. Experiences from an analysis of the face-to-face DPP lend support to this premise, as large differences in health outcomes were reported across providers, and such variation was found to be a more important factor on outcomes than variation in patient characteristics\u0026nbsp;[8].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eImplications for practice\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work has potential implications for the NHS-DDPP and the way in which the service is commissioned. NHSE appear to have used a pragmatic approach to implement the NHS-DDPP at pace and at scale, using multiple independent providers to deliver the service. Providers’ approach of adapting pre-existing programmes to meet the NHS-DDPP specification has advantages in terms of meeting a service need efficiently. Recent findings suggest that the face-to-face version of the programme achieves a reduction in population incidence of T2DM [32] and that a digital version of the service can be just as effective [11]. It could be argued that a benefit of this commissioning model is the opportunity to harness expertise already developed by commercial providers, for example around experiences in delivering health coaching. Continuing with this model for commissioning the service allows innovation from commercial providers to be capitalised upon. Notwithstanding this success, there is room for improvement in commissioning of future rounds of the service. It is recommended that future rounds of commissioning include clearer specifications for the type of support participants should receive and detail about the expected dose and scheduling of this support. We acknowledge the potential for tension between supporting fidelity of the national programme with a rigid service specification versus the need for flexibility to allow continual improvement of the programmes through user feedback, and suggest programmes are continually monitored to identify any significant drift in service delivery. The research team continue to share findings from this programme of research with NHSE and a number of improvements have already been made [18].\u0026nbsp;\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eProvider plans for the NHS-DDPP show relatively high fidelity to the NHS service specification. Despite this, there was wide variation in structural features of delivery of the NHS-DDPP across providers. This was most evident for delivery of \u0026lsquo;support\u0026rsquo;, in terms of use of health coaching and/or group support, with further variation across delivery channel and method, and dose and scheduling. Interviews with developers of the provider programmes showed that much of this variation is likely to be attributable to the ways in which the provider programmes were developed. The origin of each provider\u0026rsquo;s programme was usually a pre-existing programme that was adapted to become in line with the NHS service specification for the DDPP, and much of the ethos of the original programmes remained intact. Each provider version of the NHS-DDPP is continually improved and developed based on user experience feedback and research conducted by the providers.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eBCT\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Behaviour change technique\u003c/p\u003e\n\u003cp\u003eDDPP \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Digital Diabetes Prevention Programme\u003c/p\u003e\n\u003cp\u003eHbA1c\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Glycated haemoglobin (used as a measure of blood sugar levels over several months).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eHC\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Health Coach\u003c/p\u003e\n\u003cp\u003eNHS \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;National Health Service \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eNHSE\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;National Health Service England\u003c/p\u003e\n\u003cp\u003eNICE\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;National Institute of Health and Care Excellence\u003c/p\u003e\n\u003cp\u003eTIDieR\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Template for Intervention Description and Replication\u003c/p\u003e\n\u003cp\u003eT2DM \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Type 2 Diabetes Mellitus\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch4\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/h4\u003e\n\u003cp\u003eThis study was performed in accordance with the Declaration of Helsinki and approved by the North West Greater Manchester East NHS Research Ethics Committee (Reference: 17/NW/0426, 1\u003csup\u003est\u003c/sup\u003e August 2017) as part of a wider programme of research. Full informed consent was obtained verbally from all participants included in this study. Consent procedures for this study were approved by North West Greater Manchester East NHS Research Ethics Committee (Reference: 17/NW/0426, 1\u003csup\u003est\u003c/sup\u003e August 2017).\u003c/p\u003e\n\u003ch4\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/h4\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003ch4\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/h4\u003e\n\u003cp\u003eThe materials from digital providers and audio-recordings of interviews analysed in the current study are not publicly available due to confidentiality agreements with the provider organisations, as some information is commercially sensitive. Some datasets are available from the corresponding author on reasonable request, although authors will require the explicit permission of the relevant provider organisations.\u0026nbsp;\u003c/p\u003e\n\u003ch4\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/h4\u003e\n\u003cp\u003eThe authors declare that they have no competing interests (review if other authors added).\u003c/p\u003e\n\u003ch4\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/h4\u003e\n\u003cp\u003e\u0026nbsp;This work is independent research funded by the National Institute for Health and Care Research (Health Services and Delivery Research, 16/48/07 – Evaluating the NHS Diabetes Prevention Programme (NHS DPP): the DIPLOMA research programme (Diabetes Prevention – Long Term Multimethod Assessment)). The views and opinions expressed in this manuscript are those of the authors and do not necessarily reflect those of the National Institute for Health and Care Research or the Department of Health and Social Care.\u003c/p\u003e\n\u003ch4\u003e\u003cstrong\u003eAuthors' contributions\u003c/strong\u003e\u003c/h4\u003e\n\u003cp\u003eDPF designed the study and secured funding for this research as part of the wider DIPLOMA project. DPF supervised the research conduct and helped prepare the manuscript.\u0026nbsp;\u0026nbsp;LMM further developed design of the study, was in contact with the management teams to obtain documentation from providers, conducted research interviews, adapted TIDieR checklists for digital delivery, coded documentation using TIDieR, conducted the thematic analysis and drafted the manuscript. REH identified key structural features from specification documents, was in contact with the management teams to obtain documentation from providers, conducted research interviews, coded documentation using TIDieR and helped to prepare the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003ch4\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/h4\u003e\n\u003cp\u003e\u0026nbsp;We would like to thank the NHS-DDPP Programme team and all digital provider programme leads for providing all relevant documentation required for this manuscript. We would also like to express our appreciation to the participants who took part in an interview. With further thanks to the provider programme leads and management staff for helping to organise interviews. We are grateful to members of the DIPLOMA research team (Peter Bower, Jamie Ross and Paul Wilson) who provided comments on earlier drafts of this manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003e\u003cspan\u003eGong Q, Zhang P, Wang J, Ma J, An Y, Chen Y, Zhang B, Feng X, Li H, Chen X, et al. Morbidity and mortality after lifestyle intervention for people with impaired glucose tolerance: 30-year results of the Da Qing Diabetes Prevention Outcome Study. The lancet Diabetes \u0026amp; endocrinology. 2019;7(6):452\u0026ndash;61.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eKnowler WC, Barrett-Connor E, Fowler SE, Hamman RF, Lachin JM, Walker EA, Nathan DM. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med. 2002;346(6):393\u0026ndash;403.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eTuomilehto J, Lindstr\u0026ouml;m J, Eriksson JG, Valle TT, H\u0026auml;m\u0026auml;l\u0026auml;inen H, Ilanne-Parikka P, Kein\u0026auml;nen-Kiukaanniemi S, Laakso M, Louheranta A, Rastas M, et al. Prevention of type 2 diabetes mellitus by changes in lifestyle among subjects with impaired glucose tolerance. N Engl J Med. 2001;344(18):1343\u0026ndash;50.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eYin J, Kong APS, Chan JCN. Prevention and Care Programs Addressing the Growing Prevalence of Diabetes in China. Curr Diab Rep. 2016;16(12):130\u0026ndash;0.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eGroup TDPPR. The Diabetes Prevention Program (DPP): Description of lifestyle intervention. Diabetes Care. 2002;25(12):2165\u0026ndash;71.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eValabhji J, Barron E, Bradley D, Bakhai C, Fagg J, O\u0026rsquo;Neill S, Young B, Wareham N, Khunti K, Jebb S, et al. Early Outcomes From the English National Health Service Diabetes Prevention Programme. Diabetes Care. 2020;43(1):152\u0026ndash;60.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eBrunton L, Soiland-Reyes C, Wilson P. \u003cstrong\u003eImplications for future policy implementation: a qualitative evaluation of the national rollout of a diabetes prevention programme in England\u003c/strong\u003e. 02 August 2022, PREPRINT (Version 1).\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eMarsden AM, Bower P, Howarth E, Soiland-Reyes C, Sutton M, Cotterill S. \u0026apos;Finishing the race\u0026apos; - a cohort study of weight and blood glucose change among the first 36,000 patients in a large-scale diabetes prevention programme. Int J Behav Nutr Phys Act. 2022;19(1):7.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eHowarth E, Bower PJ, Kontopantelis E, Soiland-Reyes C, Meacock R, Whittaker W, Cotterill S. \u003cstrong\u003e\u0026apos;Going the distance\u0026apos;: an independent cohort study of engagement and dropout among the first 100 000 referrals into a large-scale diabetes prevention program\u003c/strong\u003e. BMJ open diabetes research \u0026amp; care 2020, 8(2).\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003e\u003cstrong\u003eUptake and impact of the English National Health Service digital diabetes prevention programme: observational study\u003c/strong\u003e. \u003cem\u003eBMJ Open Diabetes Research \u0026amp; Care\u003c/em\u003e 2022, \u003cstrong\u003e10\u003c/strong\u003e(3):e002736.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eMarsden AMHM, Barron E, Ross J, Valabhji J, Murray E, Cotterill S. \u003cstrong\u003eComparison of weight change between a diabetes prevention programme delivered face-to-face or by digital methods: an exploratory non-inferiority study with imputation of plausible weight outcomes, under review.\u003c/strong\u003e Under review.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003e\u003cstrong\u003eNHS\u003c/strong\u003e-\u003cstrong\u003eDPP National Service Specification\u003c/strong\u003e [https://.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eAshra NB, Spong R, Carter P, Davies MJ, Dunkley A, Gillies C, Greaves C, Khunti K, Sutton S, Yates T, et al: \u003cstrong\u003eA systematic review and meta\u003c/strong\u003e-\u003cstrong\u003eanalysis assessing the effectiveness of pragmatic lifestyle interventions for the prevention of type 2 diabetes mellitus in routine practice\u003c/strong\u003e. In. London: Public Health England; 2015.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eNational Institute of Health and Care Excellence. \u003cstrong\u003eType 2 diabetes: prevention in people at high risk. National Institute for Health and Care Excellence\u003c/strong\u003e. In.; 2017.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eBellg AJ, Borrelli B, Resnick B, Hecht J, Minicucci DS, Ory M, Ogedegbe G, Orwig D, Ernst D, Czajkowski S. Enhancing treatment fidelity in health behavior change studies: best practices and recommendations from the NIH Behavior Change Consortium. Health psychology: official journal of the Division of Health Psychology American Psychological Association. 2004;23(5):443\u0026ndash;51.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eBorrelli B. The Assessment, Monitoring, and Enhancement of Treatment Fidelity In Public Health Clinical Trials. J Public Health Dent. 2011;71(s1):52-s63.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eHawkes RE, Miles LM, French DP. Fidelity to Program Specification of the National Health Service Digital Diabetes Prevention Program Behavior Change Technique Content and Underpinning Theory: Document Analysis. J Med Internet Res. 2022;24(4):e34253.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eHawkes RE, Miles LM, Bower P, Cotterill S, French DP. Assessing and ensuring fidelity of the nationally implemented English NHS diabetes prevention programme: lessons learned for the implementation of large-scale behaviour change programmes. Health Psychol Behav Med. 2022;10(1):498\u0026ndash;513.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eMiles LM, Hawkes RE, French D. \u003cstrong\u003eHow is the behaviour change content of a nationally implemented Digital Diabetes Prevention Programme understood and used by participants? A qualitative study of fidelity of receipt and enactment.\u003c/strong\u003e Under review.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eHawkes RE, Miles LM, French D. \u003cstrong\u003eWhat behaviour change technique content is offered to service users of the nationally implemented English NHS Digital Diabetes Prevention Programme: Analysis of multiple sources of intervention content\u003c/strong\u003e Under review.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eHoffmann TC, Glasziou PP, Boutron I, Milne R, Perera R, Moher D, Altman DG, Barbour V, Macdonald H, Johnston M, et al. Better reporting of interventions: template for intervention description and replication (TIDieR) checklist and guide. BMJ. 2014;348:g1687.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eHawkes RE, Cameron E, Bower P, French DP. Does the design of the NHS Diabetes Prevention Programme intervention have fidelity to the programme specification? A document analysis. Diabet medicine: J Br Diabet Association. 2020;37(8):1357\u0026ndash;66.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eCotterill S, Knowles S, Martindale A-M, Elvey R, Howard S, Coupe N, Wilson P, Spence M. Getting messier with TIDieR: embracing context and complexity in intervention reporting. BMC Med Res Methodol. 2018;18(1):12.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eMarques M, Carey R, Norris E, Evans F, Finnerty A, Hastings J, Jenkins E, Johnston M, West R, Michie S. \u003cstrong\u003eDelivering Behaviour Change Interventions: Development of a Mode of Delivery Ontology [version 2; peer review: 2 approved]\u003c/strong\u003e. Wellcome Open Research 2021, 5(125).\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eAgarwal S, LeFevre AE, Lee J, L\u0026apos;Engle K, Mehl G, Sinha C, Labrique A. Guidelines for reporting of health interventions using mobile phones: mobile health (mHealth) evidence reporting and assessment (mERA) checklist. BMJ. 2016;352:i1174.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eDombrowski SU, O\u0026apos;Carroll RE, Williams B. Form of delivery as a key \u0026lsquo;active ingredient\u0026rsquo; in behaviour change interventions. Br J Health Psychol. 2016;21(4):733\u0026ndash;40.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003ePoduval S, Ross J, Pal K, Newhouse N, Hamilton F, Murray E. Use of the TIDieR checklist to describe an online structured education programme for type 2 diabetes. Digit health. 2020;6:2055207620975647.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eEvans TS, Dhir P, Radley D, Duarte C, Keyworth C, Homer C, Hill AJ, Hawkes RE, Matu J, McKenna J, et al: \u003cstrong\u003eDoes the design of the NHS Low Calorie Diet Programme have fidelity to the programme specification? A documentary review of service parameters and behaviour change content.\u003c/strong\u003e Under review.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eWebb TL, Joseph J, Yardley L, Michie S. Using the Internet to Promote Health Behavior Change: A Systematic Review and Meta-analysis of the Impact of Theoretical Basis, Use of Behavior Change Techniques, and Mode of Delivery on Efficacy. J Med Internet Res. 2010;12(1):e4.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003ePerski O, Blandford A, West R, Michie S. Conceptualising engagement with digital behaviour change interventions: a systematic review using principles from critical interpretive synthesis. Translational Behav Med. 2017;7(2):254\u0026ndash;67.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eYardley L, Spring BJ, Riper H, Morrison LG, Crane DH, Curtis K, Merchant GC, Naughton F, Blandford A. Understanding and Promoting Effective Engagement With Digital Behavior Change Interventions. Am J Prev Med. 2016;51(5):833\u0026ndash;42.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eMcManus E, Meacock R, Parkinson B, Sutton M. Population level impact of the NHS Diabetes Prevention Programme on incidence of type 2 diabetes in England: An observational study. Lancet Reg health Europe. 2022;19:100420.\u003c/span\u003e\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTables 1 to 2 are available in the Supplementary Files section\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-health-services-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bhsr","sideBox":"Learn more about [BMC Health Services Research](http://bmchealthservres.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/BHSR/default.aspx","title":"BMC Health Services Research","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"diabetes prevention, digital interventions, fidelity, support, TIDieR, behaviour change","lastPublishedDoi":"10.21203/rs.3.rs-2152186/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-2152186/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe National Health Service (NHS) Digital Diabetes Prevention Programme (DDPP) is a behaviour change programme for adults in England who are at high risk of developing type 2 diabetes. Four independent providers deliver the NHS-DDPP following a competitive tendering process. Although providers work to a single service specification, there is potential for some variation in the service across providers. This study 1) assesses fidelity of the structural features of the design of the NHS-DDPP compared to the service specification, 2) describes the structural features of delivery of the NHS-DDPP as implemented 3) reports developers’ views on how the structural components of the NHS-DDPP were developed and why changes were made following implementation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eUsing mixed methods, we conducted a document review of providers’ NHS-DDPP design and delivery documentation, and extracted information using the Template for Intervention Description and Replication checklist, which was adapted to capture features of digital delivery. Documentation was supplemented by content analysis of interviews with 12 health coaches involved in delivering the NHS-DDPP. Semi-structured interviews were also conducted with 6 programme developers employed by the digital providers.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eProvider plans for the NHS-DDPP show relatively high fidelity to the NHS service specification. Despite this, there was wide variation in structural features of delivery of the NHS-DDPP across providers, particularly for delivery of ‘support’ (e.g. use, dose and scheduling of health coaching and/or group support). Interviews with developers of the programmes showed that much of this variation is likely to be attributable to the origin of each provider’s programme, which was usually a pre-existing programme that was adapted to conform to the NHS-DDPP service specification. The NHS-DDPP is continually improved and developed based on user experience feedback and research conducted by the providers.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIndirect evidence suggests that variation in delivery of support could affect effectiveness of the NHS-DDPP. A priority for future research is ascertaining whether the variation in delivery of the NHS-DDPP across providers is related to any differences in health outcomes. It is recommended that future rounds of commissioning the NHS-DDPP pre-specify the type of support participants should receive, including expected dose and scheduling.\u003c/p\u003e","manuscriptTitle":"Description of the nationally implemented National Health Service Digital Diabetes Prevention Programme intervention and rationale for its development: mixed methods study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2022-11-09 09:07:27","doi":"10.21203/rs.3.rs-2152186/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major revision","date":"2023-01-27T06:19:48+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2023-01-25T22:21:14+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2022-12-02T13:58:49+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"aacbbe38-4c91-4853-a9ef-37e00df4f529","date":"2022-12-01T09:52:49+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"2d0775e0-fd6f-4a85-b1ae-3c939f4cbe5f","date":"2022-11-22T11:03:22+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2022-11-21T19:47:37+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2022-11-21T19:45:23+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2022-11-07T13:47:16+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2022-11-07T13:45:04+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Health Services Research","date":"2022-10-10T19:02:44+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-health-services-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bhsr","sideBox":"Learn more about [BMC Health Services Research](http://bmchealthservres.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/BHSR/default.aspx","title":"BMC Health Services Research","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"341c7495-2d62-42f9-af36-6b4964862a2d","owner":[],"postedDate":"November 9th, 2022","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2023-10-16T20:39:08+00:00","versionOfRecord":{"articleIdentity":"rs-2152186","link":"https://doi.org/10.1186/s12913-023-09210-3","journal":{"identity":"bmc-health-services-research","isVorOnly":false,"title":"BMC Health Services Research"},"publishedOn":"2023-04-18 20:31:35","publishedOnDateReadable":"April 18th, 2023"},"versionCreatedAt":"2022-11-09 09:07:27","video":"","vorDoi":"10.1186/s12913-023-09210-3","vorDoiUrl":"https://doi.org/10.1186/s12913-023-09210-3","workflowStages":[]},"version":"v1","identity":"rs-2152186","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-2152186","identity":"rs-2152186","version":["v1"]},"buildId":"WrCJVZZCHTDjtuVLN7oU0","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}