The NHS Low-Calorie Diet Digital Programme: Fidelity of behaviour change technique delivery.

AIMS: NHS England commissioned independent service providers to deliver the NHS Low-Calorie Diet Programme pilot. Previous research has illustrated a drift in the fidelity of behaviour change techniques (BCTs) during the delivery of the programme provided through face-to-face group or one-to-one behavioural support. The aim of this study was to assess the delivery fidelity of the BCT content in the digital delivery of the programme. METHODS: Online, app chat and phone call support content was coded using The Behaviour Change Technique Taxonomy. BCTs delivered by each service provider (N = 2) were calculated and compared to the BCTs specified in the NHS service specification and those specified in the providers' programme plans. RESULTS: Between 78% and 83% of the BCTs identified in the NHS service specification were delivered by the service providers. The fidelity of BCT delivery to those specified in providers' programme plans was 60%-65% for provider A, and 82% for provider B. CONCLUSIONS: The BCT content of the digital model used in the NHS-LCD programme adhered well to the NHS service specification and providers' plans. It surpassed what has been previously observed in face-to-face services provided through group or one-on-one behavioural support models.

Can the delivery of behavioural support be improved in the NHS England Low-Calorie Diet Programme? An observational study of behaviour change techniques.

BACKGROUND: Previous research has illustrated a drift in the fidelity of behaviour change techniques (BCTs) during the design of the pilot NHS England Low-Calorie Diet (NHS-LCD) Programme. This study evaluated a subsequent domain of fidelity, intervention delivery. Two research questions were addressed: (1) To what extent were BCTs delivered with fidelity to providers programme plans? (2) What were the observed barriers and facilitators to delivery? METHODS: A mixed-methods sequential explanatory design was employed. Remote delivery of one-to-one and group-based programmes were observed. A BCT checklist was developed using the BCT Taxonomy v1; BCTs were coded as present, partially delivered, or absent during live sessions. Relational content analysis of field notes identified observed barriers and facilitators to fidelity. RESULTS: Observations of 122 sessions across eight samples and two service providers were completed. Delivery of the complete NHS-LCD was observed for five samples. Fidelity ranged from 33% to 70% across samples and was higher for group-based delivery models (64%) compared with one-to-one models (46%). Barriers and facilitators included alignment with the programme's target behaviours and outcomes, session content, time availability and management, group-based remote delivery, and deviation from the session plan. CONCLUSIONS: Overall, BCTs were delivered with low-to-moderate fidelity. Findings indicate a dilution in fidelity during the delivery of the NHS-LCD and variation in the fidelity of programmes delivered across England. Staff training could provide opportunities to practice the delivery of BCTs. Programme-level changes such as structured activities supported by participant materials and with sufficient allocated time, might improve the delivery of BCTs targeting self-regulation.

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 in a type 2 diabetes intervention.

BACKGROUND: NHS England commissioned four independent service providers to pilot low-calorie diet programmes to drive weight loss, improve glycaemia and potentially achieve remission of Type 2 Diabetes across 10 localities. Intervention fidelity might contribute to programme success. Previous research has illustrated a drift in fidelity in the design and delivery of other national diabetes programmes. AIMS: (1) To describe and compare the programme designs across the four service providers; (2) To assess the fidelity of programme designs to the NHS England service specification. METHODS: The NHS England service specification documents and each provider's programme design documents were double-coded for key intervention content using the Template for Intervention Description and Replication Framework and the Behaviour Change Technique (BCT) Taxonomy. RESULTS: The four providers demonstrated fidelity to most but not all of the service parameters stipulated in the NHS England service specification. Providers included between 74% and 87% of the 23 BCTs identified in the NHS specification. Twelve of these BCTs were included by all four providers; two BCTs were consistently absent. An additional seven to 24 BCTs were included across providers. CONCLUSIONS: A loss of fidelity for some service parameters and BCTs was identified across the provider's designs; this may have important consequences for programme delivery and thus programme outcomes. Furthermore, there was a large degree of variation between providers in the presence and dosage of additional BCTs. How these findings relate to the fidelity of programme delivery and variation in programme outcomes and experiences across providers will be examined.

Views, perceptions, and experiences of type 2 diabetes or weight management programs among minoritized ethnic groups living in high-income countries: A systematic review of qualitative evidence.

BACKGROUND: Prevalence of both obesity and type 2 diabetes can be higher in patients from certain ethnic groups, yet uptake and adherence to current support within these groups is lower, leading to widening health inequalities in high-income countries. OBJECTIVES: The main objective of this study is to understand the views, perceptions, and experiences of and barriers and facilitators in relation to the uptake and adherence to weight management and type 2 diabetes programs in minoritized ethnic groups in high-income countries. METHODS: CINAHL, MEDLINE, PsycINFO, Scopus, Academic Search Complete, and PubMed were searched for English language studies undertaken in community-dwelling adults residing in high-income countries, who are from a minoritized ethnic group within the country of study. RESULTS: Seventeen studies were synthesized using the JBI System for the Unified Management of the Assessment and Review of Information. From these studies, 115 findings were retrieved, and seven key themes were identified: (1) family health status and program education, (2) social support, (3) challenges, (4) cultural beliefs, (5) increased awareness and dietary changes, (6) impact of psychological evaluations, and (7) considerations for future. CONCLUSIONS: Nutritional considerations for type 2 diabetes mellitus and weight management programs in high-income countries should include social, habitual, economic, and conceptual components, which should include consideration of local ethnic and cultural norms and building community relationships while creating culturally tailored programs.

Is the NHS low-calorie diet programme delivered as planned? An observational study examining adherence of intervention delivery to service specification.

Obesity and Type 2 Diabetes Mellitus (T2DM) are chronic conditions with significant personal, societal, and economic impacts. Expanding on existing trial evidence, the NHS piloted a 52-week low-calorie diet programme for T2DM, delivered by private providers using total diet replacement products and behaviour change support. This study aimed to determine the extent to which providers and coaches adhered to the service specification outlined by NHS England. An observational qualitative study was conducted to examine the delivery of both one-to-one and group-based delivery of programme sessions. Observations of 122 sessions across eight programme delivery samples and two service providers were completed. Adherence to the service specification was stronger for those outcomes that were easily measurable, such as weight and blood glucose, while less tangible elements of the specification, such as empowering service users, and person-centred delivery were less consistently observed. One-to-one sessions were more successful in their person-centred delivery, and the skills of the coaches delivering the sessions had a strong impact on adherence to the specification. Overall, the results show that there was variability by provider and delivery mode in the extent to which sessions of the NHS Low-Calorie Diet Programme reflected the intended service specification. In subsequent programmes it is recommended that one-to-one sessions are used, with accompanying peer support, and that providers improve standardised training and quality assurance to ensure specification adherence.

How is online self-reported weight compared with image-captured weight? A comparative study using data from an online longitudinal study of young adults.

BACKGROUND: Accurate anthropometric measurement is important within epidemiological studies and clinical practice. Traditionally, self-reported weight is validated against in-person weight measurement. OBJECTIVES: This study aimed to 1) determine the comparison of online self-reported weight against images of weight captured on scales in a young adult sample, 2) compare this across body mass index (BMI), gender, country, and age groups, and 3) explore demographics of those who did/did not provide a weight image. METHODS: Cross-sectional analysis of baseline data from a 12-mo longitudinal study of young adults in Australia and the UK was conducted. Data were collected by online survey via Prolific research recruitment platform. Self-reported weight and sociodemographics (for example, age, gender) were collected for the whole sample (n = 512), and images of weight for a subset (n = 311). Tests included Wilcoxon signed-rank test to evaluate differences between measures, Pearson correlation to explore the strength of the linear relationship, and Bland-Altman plots to evaluate agreement. RESULTS: Self-reported weight [median (interquartile range), 92.5 kg (76.7-112.0)] and image-captured weight [93.8 kg (78.8-112.8)] were significantly different (z = -6.76, P < 0.001), but strongly correlated (r = 0.983, P < 0.001). In the Bland-Altman plot [mean difference -0.99 kg (-10.83, 8.84)], most values were within limits of agreement (2 standard deviation). Correlations remained high across BMI, gender, country, and age groups (r > 0.870, P < 0.002). Participants with BMI in ranges 30-34.9 and 35-39.9 kg/m2 were less likely to provide an image. CONCLUSIONS: This study demonstrates the method concordance of image-based collection methods with self-reported weight in online research.

How is the NHS Low-Calorie Diet Programme expected to produce behavioural change to support diabetes remission: An examination of underpinning theory.

Background: In 2020, the National Health Service Low-Calorie Diet Programme (NHS-LCD) was launched, piloting a total diet (TDR) replacement intervention with behaviour change support for people living with Type 2 Diabetes (T2D) and excess weight. Four independent service providers were commissioned to design and deliver theoretically grounded programmes in localities across England. Aims: 1) to develop a logic model detailing how the NHS-LCD programme is expected to produce changes in health behaviour, and (2) to analyse and evaluate the use of behaviour change theory in providers' NHS-LCD Programme designs. Methods: A documentary review was conducted. Information was extracted from the NHS-LCD service specification documents on how the programme expected to produce outcomes. The Theory Coding Scheme (TCS) was used to analyse theory use in providers' programme design documents. Results: The NHS-LCD logic model included techniques aimed at enhancing positive outcome expectations of programme participation and beliefs about social approval of behaviour change, to facilitate programme uptake and behaviour change intentions. This was followed by techniques aimed at shaping knowledge and enhancing the ability of participants to self-regulate their health behaviours, alongside a supportive social environment and person-centred approach.Application and type of behaviour change theory within service providers' programme designs varied. One provider explicitly linked theory to programme content; two providers linked 63% and 70% of intervention techniques to theory; and there was limited underpinning theory identified in the programme design documents for one of the providers. Conclusion: The nature and extent of theory use underpinning the NHS-LCD varied greatly amongst service providers, with some but not all intervention techniques explicitly linked to theory. How this relates to outcomes across providers should be evaluated. It is recommended that explicit theory use in programme design and evidence of its implementation becomes a requirement of future NHS commissioning processes.