A cohort profile and process evaluation of an adult multidisciplinary behavioural and weight management service in a diverse UK population

Background : Tier 3 weight and behavioural interventions are a core part of the national health service (NHS) model of obesity management in the United Kingdom. The aim of this study is to present a cohort profile and process evaluation of an adult multidisciplinary weight management service in a diverse UK population. Methods : A retrospective cohort study of the 12-month South-East London Healthy Living Programme is reported. The programme included a diet and lifestyle behaviour change or a total meal replacement plus diet and lifestyle intervention. Community-based group sessions were delivered monthly either virtually or face-to-face. Sociodemographic, clinical, anthropometric, and behavioural patient data were collected at baseline. Process outcomes including referrals, engagement and programme completion rates are reported. Data analyses were conducted using independent t-tests for sociodemographic characteristics and multivariate logistic regression was performed to determine predictors of programme completion. Results : 4,499 individuals (47 ± 13.5 years, 78% female, 36% Black African and Caribbean, 49% living in areas of high deprivation) were referred to the service between April 2018-March 2023. Early engagement was 67% and 61% for session 1 and 2 respectively and engagement declined to <50% by session 4. Programme completion rate was 43% (n = 904). Females were more likely to complete (OR 1.509, p= 0.018), whereas people of Black African and Caribbean ethnicity (OR 0.074, p=0.023), and participants with lower relational support (OR 0.701, p=0.045) predicted lower completion rates. Conclusion : Programme completion was below 50% which is consistent with the evidence on Tier 3 interventions. Males and people of ethnic minority ethnic heritage were less likely to complete the programme. While early engagement was relatively high, it declined substantially across the programme. Efforts to increase engagement particularly among ethnic minorities and males are warranted.