The 10-Year Cost-Effectiveness of Lifestyle Intervention or Metformin for Diabetes Prevention

OBJECTIVE The Diabetes Prevention Program (DPP) and its Outcomes Study (DPPOS) demonstrated that either intensive lifestyle intervention or metformin could prevent type 2 diabetes in high-risk adults for at least 10 years after randomization. We report the 10-year within-trial cost-effectiveness of the interventions. RESEARCH DESIGN AND METHODS Data on resource utilization, cost, and quality of life were collected prospectively. Economic analyses were performed from health system and societal perspectives. RESULTS Over 10 years, the cumulative, undiscounted per capita direct medical costs of the interventions, as implemented during the DPP, were greater for lifestyle ($4,572) than metformin ($2,281) or placebo ($752). The cumulative direct medical costs of care outside the DPP/DPPOS were least for lifestyle ($26,810 lifestyle vs. $27,384 metformin vs. $29,007 placebo). The cumulative, combined total direct medical costs were greatest for lifestyle and least for metformin ($31,382 lifestyle vs. $29,665 metformin vs. $29,759 placebo). The cumulative quality-adjusted life-years (QALYs) accrued over 10 years were greater for lifestyle (6.89) than metformin (6.79) or placebo (6.74). When costs and outcomes were discounted at 3% and adjusted for survival, lifestyle cost $12,878 per QALY, and metformin had slightly lower costs and nearly the same QALYs as placebo. CONCLUSIONS Over 10 years, from a payer perspective, lifestyle was cost-effective and metformin was marginally cost-saving compared with placebo. Investment in lifestyle and metformin interventions for diabetes prevention in high-risk adults provides good value for the money spent.