Short-Term Cost-Effectiveness of Switching to Insulin Degludec in Japanese Patients with Type 2 Diabetes Receiving Basal–Bolus Therapy

Introduction With one of the fastest aging populations in the world, demographic changes in Japan are a major public health concern due to the substantial burden that aging-associated diseases, such as type 2 diabetes (T2D), place on public healthcare systems. The aim of this analysis was to evaluate the short-term cost-effectiveness of switching Japanese patients with T2D receiving basal–bolus insulin therapy from their previous basal insulin to insulin degludec (degludec) under conditions of routine clinical practice. Methods A previously published, open-source model developed in Microsoft Excel was used to evaluate the cost-effectiveness of switching basal–bolus insulin therapy from patients' previous basal insulin to degludec versus continuing the previous basal insulin therapeutic regimen in terms of costs (2018 Japanese Yen [JPY]) and quality-adjusted life years (QALYs), from a Japanese public healthcare payer perspective. The model captured hypoglycemia rates and insulin dosing over a 1-year time horizon, and was informed by Japanese real-world evidence from the T2D cohort ( N = 135) of the Kumamoto Insulin Degludec Observational study. Results Treatment with degludec was associated with improved effectiveness (+ 0.0354 QALYs), driven by lower daytime non-severe hypoglycemia rates with degludec, at slightly higher annual treatment costs (JPY 9510) versus continuing the previous basal insulin. Switching basal insulin to degludec was found to be a cost-effective intervention with an incremental cost-effectiveness ratio (JPY 268,811 per QALY gained) substantially below the willingness-to-pay threshold of 5 million JPY per QALY used in the Japanese Health Technology Assessment framework. Sensitivity analyses confirmed the robustness of this finding and indicated that the daytime non-severe hypoglycemia benefit with degludec was a key driver of outcomes in the base case. Conclusion Based on Japanese real-world evidence, our analysis suggests that switching Japanese patients with T2D receiving a basal–bolus regimen from their previous basal insulin to degludec would be highly cost-effective. These data may help decision-makers in Japan allocate healthcare resources efficiently. Trial Registration The KIDUNA study is registered with the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR): UMIN000021569. Funding Novo Nordisk Pharma Ltd. Japan.