Cost-effectiveness of incentives for physical activity in coronary heart disease in Germany: pre-trial health economic model of a complex intervention following the new MRC framework.

ABSTRACT

Objectives: The German Incentives for Physical Activity in Cardiac Patients trial is a three-arm, randomised controlled trial for secondary prevention of coronary heart disease (CHD). Guidance for developing complex interventions recommends pre-trial health economic modelling. The aim of this study is to model the long-term cost-effectiveness of the incentive-based physical activity interventions in a population with CHD. Methods: A decision-analytical Markov model was developed from a health services provider perspective, following a cohort aged 65 years with a previous myocardial infarction for 25 years. Monetary and social incentives were compared relative to no incentive. Intervention effects associated with physical activity were used to determine the costs, quality-adjusted life-years (QALYs) gained, incremental cost-effectiveness and cost-utility ratios. The probability of cost-effectiveness was calculated through sensitivity analyses. Results: The incremental QALYs gained from the monetary and social incentives, relative to control, were respectively estimated at 0.01 (95% CI 0.00 to 0.01) and 0.04 (95% CI 0.02 to 0.05). Implementation of the monetary and social incentive interventions increased the costs by €874 (95% CI €744 to €1047) and €909 (95% CI €537 to €1625). Incremental cost-utility ratios were €25 912 (95% CI €15 056 to €50 210) and €118 958 (95% CI €82 930 to €196 121) per QALY gained for the social and monetary incentive intervention, respectively. With a willingness-to-pay threshold set at €43 000/QALY, equivalent to the per-capita gross domestic product in Germany, the probability that the social and monetary incentive intervention would be seen as cost-effective was 95% and 0%, respectively. Conclusions: Exercise-based secondary prevention using inventive schemes may offer a cost-effective strategy to reduce the burden of CHD.