Healthy Eating & Active Lifestyles for Diabetes: Feasibility Trial (HEAL-D)

This study is a feasibility trial with an embedded process evaluation of the HEAL-D intervention compared with usual care. The study will use a randomised controlled trial (RCT) design, with individual patients as the unit of randomisation, evaluating the HEAL-D programme against usual care. The RCT design has been chosen primarily to evaluate the feasibility of recruiting and retaining a control arm, as well as to define what constitutes 'usual care' and the variability within that. Patients with diagnosed type 2 diabetes (T2D) will be recruited from General Practice surgeries in the London Boroughs of Lambeth and Southwark. In addition participants from the phase 1 co-design study will be invited to participate and self-referral methods will also be used, for example posters and advertisements in community locations. Patients will be eligible if they have a documented diagnosis of T2D and are of self-declared African or Caribbean ethnicity. Patients with complex therapeutic dietary needs may be ineligible if their individual needs are deemed incompatible with the aims of the intervention. Additionally patients who are unable to communicate in English will be ineligible.

A pragmatic sample size of 80 randomised patients, 40 in each arm, is anticipated to be sufficient to evaluate the programme, allowing for 20% drop-out/non-completion. As this is a feasibility trial it is not powered to detect statistically significant intervention effects, unless these estimated effects are extremely large. The purpose of the study is to assess the feasibility and acceptability of the intervention and of trial methods, and to provide estimates of key parameters such as potential effect sizes, recruitment and retention rates of the trial and participation rates of the programme, so that the optimal design of a full-scale trial can be determined.

The HEAL-D intervention consists of 7 sessions; the programme will have a flexible schedule allowing participants to attend either fortnightly or monthly sessions. Each patient who participates will be in the study for approximately 7 months and will be asked to complete two assessment visits, one at baseline and one 6-8 months later, depending on the intensity of programme attendance. A range of potential primary and secondary outcome data will be collected including HbA1c, blood lipids (triglyceride, total cholesterol, HDL-cholesterol, LDL-cholesterol), body weight, waist circumference, diabetes knowledge, diabetes and dietary competence, diabetes empowerment, perceived social support, quality of life, dietary intake, and physical activity. Participants may also participate in an interview or focus group as part of the study's process evaluation.