Clinical effectiveness and cost‐effectiveness of first‐line early combination of dipeptidyl peptidase 4 inhibitors and metformin in patients with type 2 diabetes in Taiwan: A modelling study

AIMS: Early dipeptidyl peptidase-4 inhibitors and metformin (DPP4i-Met) combination has been shown to extend the time to treatment failure and provide better glycaemic control for newly diagnosed type 2 diabetes (T2D) patients; however, the long-term clinical and economic outcomes of early DPP4i-Met combination remain unknown. We seek to assess the comparative long-term clinical and cost-effectiveness of DPP4i-Met versus Met for treatment-naïve T2D patients with inadequately controlled HbA1c (i.e., ≥8.5%). METHODS: The IQVIA CORE Diabetes Model was used to simulate the quality-adjusted life years (QALYs) and healthcare costs over a lifetime from Taiwan's National Health Insurance Administration's perspective, with both QALYs and costs discounted at 3% annually. Model inputs were taken from the analyses of Taiwanese or Asian populations. Primary outcomes included the number needed to treat (NNT) to prevent one case of a clinical event and the incremental cost-effectiveness ratios (ICERs). Costs are presented in 2023 US dollars. RESULTS: Over 40 years of projection, Met-DPP4i-treated patients had fewer complications than those using Met alone (e.g., lowering the incidence of stroke by 2.21% [2.68, 1.74]). The NNT using DPP4i-Met versus Met alone to prevent one case of stroke, microalbuminuria, neuropathy and background retinopathy was 45, 135, 65 and 182, respectively. Such long-term benefits in reducing costly complications offset the higher treatment cost of DDP4i-Met versus Met ($5796 vs. $5484/person). As a result, using DPP4i-Met versus Met yielded 0.086 QALYs gained and savings of $489 for overall treatment-naïve T2D patients and 0.064 QALYs gained and savings of $714 for young-onset T2D patients. CONCLUSIONS: Early DPP4i-Met provides long-term clinical and economic benefits compared to Met alone for newly diagnosed T2D patients, including those with young-onset T2D.