Cost-Effectiveness of the National Diabetes Prevention Program: A Real-World, 2-Year Prospective Study

Abstract

OBJECTIVE We evaluated the real-world cost-effectiveness of the National Diabetes Prevention Program (NDPP) for people with prediabetes in a large workforce with employer-sponsored health insurance. RESEARCH DESIGN AND METHODS We performed difference-in-differences analyses using individual-level health insurance claims and survey data for 5,948 adults with prediabetes who enrolled (n = 575) or did not enroll (n = 5,373) in the NDPP to assess NDPP’s effects on health economic outcomes. We assessed direct medical costs for the year before the NDPP enrollment/index date and for 2 years thereafter; EuroQol 5-Dimension 5-level questionnaire (EQ-5D-5L) utility scores at baseline, 1 year, and 2 years; and quality-adjusted life-years (QALYs) over 2 years. We used propensity score weighting to adjust for potential bias due to self-selection for enrollment, multiple imputation to handle missing data, and bootstrapping to produce CIs. We adopted a health care sector perspective and discounted costs and QALYs at 3% annually. Costs were expressed in 2020 U.S. dollars. RESULTS Compared with nonenrollees, each NDPP enrollee had an average reduction of $4,552 (95% CI −13,231, 2,014) in 2-year total direct medical costs. Cost savings were primarily related to hospitalizations, outpatient visits, and emergency room visits. Compared with nonenrollees, each enrollee had no difference in EQ-5D-5L utility scores at 2 years or QALYs gained over 2 years. The uncertainty analyses found that enrollment in the NDPP had an 88% probability of saving money and 84% probability of being cost-effective at a willingness-to-pay threshold of $100,000/QALY-gained over 2 years. CONCLUSIONS In this real-world population with prediabetes, enrollment in the NDPP was likely to provide cost savings.