Effectiveness of a specified physiotherapy-led tier 2 eHealth weight management programme in a multi-ethnic cohort: A cross-sectional study

Background: Tier 2 multi-component lifestyle interventions are integral to the National Health Service weight management pathway. While eHealth delivery may increase accessibility of these interventions many digital programmes lack specificity and repeatability, making it challenging to evaluate which components are most effective. Objective: This study reports on a tier 2 eHealth weight management intervention, designed using the rehabilitation treatment specification system (RTSS), delivered in an ethnically diverse population. Methods: The tier 2 eHealth intervention was developed using the RTSS, which includes treatment components containing three elements of treatment theory: a target, a mechanism of action and ingredients. Participants (≥18 years) had body mass index >30 or >27.5 kg/m² ethnic-specific. Primary outcomes were weight change and the proportion of participants achieving at least 3% and 5% weight loss. Secondary outcomes included physical activity, dietary quality, eating behaviours and quality of life. Results: Of 579 enrolled participants, outcome data were available for 322. Programme completion rate was 45%. Forty per cent of the programme completers lost ≥3% of weight (9.2 ± 11.3 kg (10%)), and 27% lost ≥5% (−11.8 ± 13 kg (12.4%)). Improvements in secondary outcomes were observed across ethnic and deprivation groups. Conclusion: Programme completion for this tier 2 eHealth intervention was below the recommended levels but is consistent with the literature. Weight and behavioural improvements were observed across ethnicities and deprivation levels. The RTSS-based intervention provides a replicable framework that enhances intervention fidelity, supports evaluation and informs future programme development. Further research is needed to optimize completion rates to improve outcomes.