Within-trial cost-effectiveness of lifestyle intervention or metformin for the primary prevention of type 2 diabetes.

OBJECTIVE The Diabetes Prevention Program (DPP) demonstrated that intensive lifestyle and metformin interventions reduced the incidence of type 2 diabetes compared with a placebo intervention. The aim of this study was to assess the cost-effectiveness of the lifestyle and metformin interventions relative to the placebo intervention. RESEARCH DESIGN AND METHODS Analyses were performed from a health system perspective that considered direct medical costs only and a societal perspective that considered direct medical costs, direct nonmedical costs, and indirect costs. Analyses were performed with the interventions as implemented in the DPP and as they might be implemented in clinical practice. RESULTS The lifestyle and metformin interventions required more resources than the placebo intervention from a health system perspective, and over 3 years they cost approximately US dollars 2250 more per participant. As implemented in the DPP and from a societal perspective, the lifestyle and metformin interventions cost US dollars 24400 and US dollars 34500, respectively, per case of diabetes delayed or prevented and US dollars 51600 and US dollars 99200 per quality-adjusted life-year (QALY) gained. As the interventions might be implemented in routine clinical practice and from a societal perspective, the lifestyle and metformin interventions cost US dollars 13200 and US dollars 14300, respectively, per case of diabetes delayed or prevented and US dollars 27100 and US dollars 35000 per QALY gained. From a health system perspective, costs per case of diabetes delayed or prevented and costs per QALY gained tended to be lower. CONCLUSIONS Over 3 years, the lifestyle and metformin interventions were effective and were cost-effective from the perspective of a health system and society. Both interventions are likely to be affordable in routine clinical practice, especially if implemented in a group format and with generic medication pricing.