Abstract 19: Cost-effectiveness of the Stepwise Approach to Diabetes Prevention in India

Abstract

Introduction: Expert guidelines recommend a stepwise approach (lifestyle modification followed by addition of metformin in those not meeting goals) in high-risk people to delay progression to diabetes. However, there is scant evidence on the cost-effectiveness of implementing stepwise diabetes prevention. We estimated the 3-year within trial cost-effectiveness of a stepwise diabetes prevention approach in the Diabetes Community Lifestyle Improvement Program (D-CLIP) study in Chennai, India. Hypothesis: We assessed the cost-effectiveness of a stepwise diabetes prevention approach in India. Methods: The D-CLIP study was a randomized, controlled, translation trial in 578 overweight/obese Asian Indian adults with isolated impaired glucose tolerance (IGT) and/or isolated impaired fasting glucose (IFG), comparing a 6-month lifestyle modification curriculum and stepwise addition of metformin vs. standard lifestyle advice. We assessed direct medical costs including costs to deliver the intervention, general health care utilization, and direct non-medical costs. We also calculated costs for screening which included identifying and recruiting eligible individuals with IGT and/or IFG. Health effects were measured as absolute reductions in cumulative diabetes risk and in quality adjusted life years (QALYs) gained. Generalized linear regressions models adjusted for age, sex and baseline levels were fitted to estimate incremental costs and health effects. Bootstrapping was applied to describe the uncertainty around incremental cost-effectiveness ratios (ICER). Results: Over 3 years, the intervention resulted in incremental direct medical costs of 211 USD; incremental direct non-medical costs of 34 USD, an absolute diabetes risk reduction of 10.2%, and incremental QALYs gained of 0.098 per person. The absolute diabetes risk reduction in people with IFG was 6.4%, with IGT was 9% and with both IFG and IGT was 8.1%. ICERs from a multi-payer perspective (including the screening costs) averaged 4,275 USD per diabetes case prevented/delayed. That figure was 5,220 USD in people with IFG, 2,627 USD with IGT and 3,312 USD with both IFG and IGT. ICERs from a multi-payer perspective (including the screening costs) averaged 4,472 USD per QALY gained. That figure was 4,589 USD in people with IFG, 4,270 USD with IGT and 4,335 USD with both IFG and IGT. ICERs from a societal perspective were slightly higher. In the sensitivity analysis, with the scenario of a 50% increase/decrease in screening and intervention costs, from a multi-payer perspective, the average of ICERs varied 1,907 to 6,420 USD per diabetes case prevented, from 1,995 to 6,715 USD per QALY gained. Conclusions: In conclusion, a stepwise approach for diabetes prevention is likely to be cost-effective over a three-year time horizon.