Award Title: A coproduced mixed method evaluation of the NHS England low calorie diet implementation pilot
Funder: Department of Health and Social Care

Abstract: WHY IS THIS STUDY NEEDED? Recent studies have shown that for some people who live with overweight or obesity and type 2 diabetes, a low calorie diet can help them lose weight, reduce their risk of heart disease, and put their diabetes into remission. The NHS wants to test whether or not a low calorie diet can be used to support patients in 10 areas in England.  Eligible patients in these areas will receive low calorie meal replacement products (e.g. bars, shakes, soups) and ongoing support to help manage their eating. The support aspect will be delivered and tested in three different ways: digital technology, face to face group support, or face to face one to one support._x000D_
THE PROPOSED STUDY THEREFORE AIMS TO UNDERSTAND:_x000D_
-	Whether the low calorie diet programme that has been tested in studies, can work as well when delivered by the NHS, in helping patients to lose weight, improve their diabetes &/or reduce their risk of heart disease; _x000D_
-	What patients perceive to be the benefits and disadvantages of the programme;_x000D_
-	How much it costs the NHS, whether there are any costs to patients, and if so, if this a barrier to them completing the programme; _x000D_
-	Which method of support (1:1, group or digital) is more preferable to patients;_x000D_
-	What patients and staff involved in the programme think about it;_x000D_
-	Whether the programme is being delivered as it is intended (e.g. whether all eligible patients are being invited to receive the programme, whether patients are able to follow it as required, which eligible patients are not using the programme, or are having difficulty following it, and why). _x000D_
-	Whether the programme should be made available to every area across England, and if so, are any changes to the programme required before this happens._x000D_
HOW ARE WE GOING TO DO THIS STUDY? Work will be undertaken in several stages:_x000D_
1.	We will talk to NHS staff involved with the programme, and to staff who will be delivering the programme, to ask them for their views about what has worked well, what has not, and why._x000D_
2.	We will ask all patients who have been referred to the programme to complete a short survey to ask for their views about the programme. _x000D_
3.	We will take a detailed look at the lived experiences of a small sample of patients from different backgrounds and areas. This will involve talking to patients and asking them to take photographs or video diaries to document their journey._x000D_
4.	We will look at how much the programme costs to run for the NHS, patients and any supporting organisations, and whether it offers value for money._x000D_
5.	We will look at whether it is feasible to make the programme available across England._x000D_
WHO WILL BE INVOLVED? This study will be carried out by a team of experts in weight management, diabetes and programme evaluation. The team also includes an expert patient panel, who will be involved throughout, in co-designing the study, liaising with patients, collecting data and helping to share the findings. We will also work closely with NHS England who are organising the programme for the 10 areas and collecting data on the patients’ weight and health._x000D_
HOW WILL WE SHARE OUR FINDINGS? We will share learning from this study in a number of different ways. This will include: writing reports for NHS England and academic papers, giving presentations at local and international events, producing short films and illustrated journals describing what we did, what we found and how the findings will be used._x000D_
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study website: www.remission.study

Lay Abstract: Background: An NHS Low Calorie Diet (LCD) delivered via 1:1, group or digital support will be piloted in patients with excess weight and type 2 diabetes. Aim: To coproduce a qualitative & economic evaluation of the NHS LCD pilot, integrated with NHS data to provide an enhanced understanding of the long-term cost effectiveness, implementation, equity & transferability across broad & diverse populations. Research questions & methods: A multi-disciplinary patient-led programme of 5 work packages (WP): WP1 PROJECT MANAGEMENT, COPRODUCTION, PUBLIC AND PATIENT INVOLVEMENT (PPI) & DISSEMINATION: will 1) coordinate project management, PPI, co-production & evaluation reports: integrating WP2-5 with NHS analyses; 2) oversee dissemination: illustrative journals, infographics, website, social media, films, presentations & journal articles. WP2 SERVICE DELIVERY & FIDELITY: will use documentary review, session observations, interviews with NHS support staff & focus groups with providers, to address the following research questions (RQ): RQ1 What are the theoretical principles, behaviour change components, content &  mode of delivery of the programme, &  how do these vary across sites & providers? RQ2 To what extent does the staff training delivered by each provider address behaviour change theory & content, & how does this vary across sites & providers? RQ3 To what extent is the delivery of the NHS LCD delivered with fidelity to NHS specifications? RQ4 What are provider & NHS support staff experiences of the service & what do they perceive to be key barriers & facilitators to effective delivery & integration into routine care? WP3 PATIENT EXPERIENCE & INEQUITIES: will be undertaken using longitudinal patient surveys, interviews & photovoice. These findings will be integrated with NHS data to address: RQ5 To what extent is the content of the NHS LCD understood & applied by patients? RQ6 Do sociodemographic characteristics influence access, uptake, compliance & success on the NHS LCD, & does this vary across the different delivery models? RQ7 What aspects of the service work & do not work, for whom, in what context & why? RQ8 How can the service be improved in the future, to enhance patient experience, & ensure any inequities are addressed? WP4 ECONOMIC EVALUATION: will use patient-level simulation modelling to estimate long-term cost-effectiveness of the NHS LCD (cost per QALY) to inform commissioning.  Micro-costing for each of the delivery models will address: RQ9 What are the costs of delivering the NHS LCD programme from an NHS perspective &  how do they a) differ across the different delivery models & b) compare to estimates provided in previous trials? RQ10 What are the costs of the NHS LCD to participants & how do they differ by delivery method & socio-demographics? This & NHS data will also be used in patient-level simulation models to address RQ11: What is the long-term cost-effectiveness of the NHS LCD in terms of cost per QALY & how does this vary by delivery method & patient characteristics?.  We will also replicate the methods used in previous trials to address: RQ12 How does the cost & short-term outcome data collected in this study affect the estimates of cost-effectiveness in previous trials? WP5 TRANSFERABILITY ASSESSMENT: will employ a theoretical model for the assessment of transferability to address RQ13: What are the policy implications for wide-spread adoption of the programme? Anticipated delivery timeframe & impact: Nov 20 to Oct 23. Findings will inform national roll out.

Research Activity Codes: 8.1 ORGANISATION AND DELIVERY OF SERVICES;8.2 HEALTH AND WELFARE ECONOMICS
Health Categories: METABOLIC AND ENDOCRINE