The cost-effectiveness of diabetes prevention: results from the Diabetes Prevention Program and the Diabetes Prevention Program Outcomes Study

William H. Herman

The Diabetes Prevention Program (DPP) was a randomized, controlled clinical trial. It demonstrated that among high-risk individuals with impaired glucose tolerance, diabetes incidence was reduced by 58 % with lifestyle intervention and 31 % with metformin compared to placebo. During the Diabetes Prevention Program Outcomes Study (DPPOS), all DPP participants were unmasked to their treatment assignments, the original lifestyle intervention group was offered additional lifestyle support, the metformin group continued metformin, and all three groups were offered a group-implemented lifestyle intervention. Over the 10 years of combined DPP/DPPOS follow-up, diabetes incidence was reduced by 34 % in the lifestyle group and 18 % in the metformin group compared to placebo. The purpose of this article is to review and synthesize analyses published by the DPP/DPPOS Research Group that have described the cost-effectiveness of diabetes prevention. We describe the resource utilization and costs of the DPP and DPPOS interventions, the costs of non-intervention-related medical care, the impact of the interventions on diabetes progression and quality-of-life, and the cost-effectiveness of the interventions from health system and societal perspectives. Cost-effectiveness analyses were performed with a 3-year time horizon using DPP data, a lifetime time horizon that simulated 3-year DPP data, and a 10-year time horizon using combined DPP/DPPOS data. Although more expensive than the placebo intervention, the greater costs of the lifestyle and metformin interventions were offset by reductions in the costs of nonintervention-related medical care. Every year after randomization, quality-of-life was better for participants in the lifestyle intervention compared to those in the metformin or placebo intervention. In both the simulated lifetime analysis and the 10-year within trial economic analysis, lifestyle and metformin were extremely cost-effective (that is, improved outcomes at a low incremental cost) or even cost-saving (that is, improved outcomes and reduced total costs) compared to the placebo intervention. The implementation of diabetes prevention programs in high-risk individuals will result in important health benefits and represents a good value for money. NCT00004992 (DPP) and NCT00038727 (DPPOS).