RESUMEN
BACKGROUND: The purpose of this paper is to assess the cost-effectiveness of a proportionate universal programme to reduce physical inactivity (Leeds Let us Get Active (LLGA)) in adults. METHODS: A continuous-time Markov chain model was developed to assess the cost implications and QALY gains associated with increases in physical activity levels across the adult population. A parametric survival analysis approach was applied to estimate the decay of intervention effect over time. Baseline model data were obtained from previous economic models, population-based surveys and other published literature. A cost-utility analysis was conducted from a health care sector perspective over the programme duration (39 months). Scenario and probabilistic sensitivity analyses were performed to test the robustness of cost-effectiveness results. RESULTS: In total, 51 874 adult residents registered to the programme and provided baseline data,19.5% of which were living in deprived areas. Under base case assumptions, LLGA was found to be likely to be cost-effective. However, variations in key structural assumptions showed sensitivity of the results. CONCLUSIONS: Results from this study suggest a non-negligible level of uncertainty regarding the effectiveness, and therefore, cost-effectiveness of a universal offer of free leisure centre-based exercise that targets hard to reach groups. Further data collection and a shift towards prospective evaluations are needed.