Background: Several long-term models have been developed to compare the economic impact of alternative anti-diabetic treatments. However short-term models, based on actual trial data, might give more accurate results and be preferable over long-term models for estimating costs and benefits in short term.
Objective: To assess the economic impact of the antidiabetic drug dapagliflozin (DAPA), a sodium-glucose cotransporter-2 (SGLT-2) inhibitor, and dipeptidyl peptidase-4 inhibitors (DPP-4i) combined with metformin in the treatment of T2D.
Methods: A short-term decision-analytic model with one year time horizon was developed using a payer’s perspective for United States (US). Costs and benefits associated with four clinical end points (glycated hemoglobin [HbA1c], body weight, systolic blood pressure (SBP), and risk of hypoglycemia) were evaluated in the analysis. A network meta-analysis was utilized to evaluate the impact of DAPA vs. DPP-4i on these clinical end points. Data for costs and QALYs associated with a per unit change in these clinical end points was taken from published literature. Drug prices were taken from annual wholesale price list. All costs were inflation-adjusted to 2016 costs using the medical care component of the consumer price index. Total costs (medical and drug), total QALYs, and incremental cost effectiveness ratios (ICERs) were estimated. Sensitivity analyses were performed as well. Results from the short-term model were compared with long term models published for these treatments.
Results: Total annual medical cost for DAPA was $1,119 less than that for DPP-4i, with the difference mainly attributable to cost associated with weight change ($860). Treatment with DAPA resulted in an average QALY gain of 0.0587 per treated patient compared to DPP-4i. DAPA was cost-saving when compared to DPP-4i. Among all the four clinical end points, change in weight had the greatest impact on total annual costs and ICERs. Probabilistic sensitivity analysis demonstrated that total annual cost for DAPA was less than that for DPP-4i in more than 97% of simulations and DAPA had a 97% probability of being cost-saving compared with DPP-4i. Results from the short-term model were similar to published long term models.
Conclusions: Our analysis showed that DAPA was cost saving when compared with DPP-4i in the US setting. Furthermore, the results suggest that among the four composite clinical endpoints, change in weight had greater impact on cost-effectiveness results. In addition, our short-term model provides results similar to published long term models.