Cost-effectiveness analysis of dapagliflozin treatment versus metformin treatment in Chinese population with type 2 diabetes

Background and objective: Dapagliflozin is the first SGLT2 inhibitor available in China, where the disease burden of diabetes and its complications is very heavy. Because a new diabetes treatment strategy for diabetes should consider its cost-effectiveness, compared with an existing treatment, this study aimed to examine the cost-effectiveness between dapagliflozin and metformin treatment in China. Methods: The Cardiff Diabetes Model (CDM) was used to estimate cost effectiveness and macro- and micro-vascular outcomes of dapagliflozin vs metformin. The CDM effectiveness inputs were derived from indirect comparative efficacy data from meta-analysis of 71 studies comparing monotherapy and add-on therapy of dapagliflozin vs metformin: dapagliflozin or metformin monotherapy, add-on therapy with other oral hypoglycemic agents, and add-on therapy with insulin. Direct medication costs and medical costs on treating diabetes were calculated based on published and local sources. A discount rate of 3% was applied to both costs and health effects. Univariate and probabilistic sensitivity analyses (PSA) were performed to assess uncertainties. Results: The total healthcare costs accumulated over the lifetime on dapagliflozin treatment arm was 8,626 Chinese yuan higher than the metformin treatment arm for an individual patient, and the quality adjusted life years (QALYs) gained with dapagliflozin treatment was 0.8 more than metformin treatment. Therefore, an incremental cost-effectiveness ratio was 10,729 yuan per QALY gained for dapagliflozin treatment arm vs metformin treatment arm. The cost-effectiveness results were robust to various sensitivity analyses. Conclusion: Dapagliflozin treatment was more cost-effective compared with metformin treatment for Chinese type 2 diabetes patients. However, the findings of favorable cost-effectiveness results for dapagliflozin are largely driven by the effects of favorable weight profile on clinical, utility, and costs in the Cardiff model.