Cost-Effectiveness Analysis of Triple Oral Antidiabetic Drug Combination in Patients With Type 2 Diabetes Mellitus: An Outpatient Study in Indonesia.

BACKGROUND: Diabetes mellitus (DM) is a chronic metabolic disorder characterized by persistent hyperglycemia. Initial therapy for type 2 diabetes typically starts with metformin monotherapy, but because of its progressive nature, combination therapy is often required to achieve glycemic targets. However, research on combination therapy with three oral antidiabetic drugs is currently limited. OBJECTIVE: This study assessed direct medical costs and the cost-effectiveness of a combination of triple oral antidiabetics with first-line metformin combined with glimepiride, pioglitazone, and DPP-4 inhibitors (sitagliptin/vildagliptin), among type 2 DM patients treated in the outpatient clinic of Dr. Ramelan Central Naval Hospital, Surabaya, Indonesia. METHODOLOGY: A retrospective cross-sectional analysis was conducted from the hospital perspective using medical records and cost data from January to December 2024. Eligible patients had type 2 DM, received a combination of triple oral antidiabetics with metformin as first-line treatment combined with glimepiride, pioglitazone, and DPP-4 inhibitors (sitagliptin/vildagliptin), attended monthly follow-ups, had at least two HbA1c measurements, and had complete clinical and cost data. Direct medical costs included doctor services, drug acquisition costs, and laboratory monitoring costs. RESULTS: A total of 79 patients were included, 60.8% male, with an average (SD) age of 54.9 (9.26) years, and 69.6% with comorbidities. Compared with the combination of metformin + glimepiride + pioglitazone, the combination of metformin + sitagliptin/vildagliptin + glimepiride and metformin + sitagliptin/vildagliptin + pioglitazone was more cost-effective, with ICER values of IDR -162,119.77; IDR 845,655.5, respectively. Both ICER values were below the willingness-to-pay (WTP) threshold. One-way sensitivity analysis showed that the model results were relatively robust to parameter variations of ±20%. In the combination of metformin + sitagliptin/vildagliptin + glimepiride vs metformin + glimepiride + pioglitazone, laboratory monitoring costs had the greatest influence on the ICER value. Meanwhile, the combination comparison metformin + sitagliptin/vildagliptin + pioglitazone vs metformin + glimepiride + pioglitazone was most sensitive to changes in effectiveness (ΔHbA1c). CONCLUSION: Metformin + sitagliptin/vildagliptin + glimepiride and metformin + sitagliptin/vildagliptin + pioglitazone are both more cost-effective compared to metformin + glimepiride + pioglitazone in this setting.