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

Abstract

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.