Economic Evaluation of Thiazolidinediones as Add-on Therapy for Treatment of Type 2 Diabetic Patients in the Taiwanese National Health Insurance System
FEI-YUAN Hsiao1 *, C. DANIEL Mullins2 AND WENG-FOUNG Huang3
1. Graduate Institute of Clinical Pharmacy College of Medicine, National Taiwan University, Taipei, Taiwan, R.O.C.
2. Pharmaceutical Health Services Department University of Maryland School of Pharmacy Baltimore, U.S.A.
3. Institute of Health and Welfare Policy, National Yang-Ming University, Taipei, Taiwan, R.O.C.
Graduate Institute of Clinical Pharmacy College of Medicine, National Taiwan University, Taipei, Taiwan, R.O.C. Pharmaceutical Health Services Department University of Maryland School of Pharmacy Baltimore, U.S.A. Institute of Health and Welfare Policy, National Yang-Ming University, Taipei, Taiwan, R.O.C.
(Received: June 21, 2011; Accepted: December 29, 2011)
ABSTRACT
The cost-effectiveness of adding the two health insurance covered thiazolidinediones (TZDs)- rosiglitazone or pioglitazone, to metformin in treating type 2 diabetes mellitus was assessed from a Taiwanese National Health Insurance (NHI) perspective.
This analysis was based on patient-level data extracted from Taiwan's NHI databases. Type 2 diabetic patients who received consecutive metformin treatments between 2001 and 2005 were identified. Clinical effectiveness, a proxy of glycemic control (time to insulin dependence), and direct medical cost were also estimated. Incremental cost-effectiveness ratio (ICER) was calculated and expressed as cost per delayed year to insulin dependence.
Compared to add-on non-TZDs, add-on rosiglitazone and pioglitazone were associated with delays of additional 151 days (0.41 years) and 101 days (0.28 years) in insulin dependence, respectively. Total mean medical costs were higher in add-on TZDs users compared to add-on non-TZDs users. The additional total medical costs of add-on rosiglitazone or pioglitazone were comparable, with ICERs of 95,874 and 95,485 New Taiwan (NT) dollars per year delay in insulin dependence, respectively.
Add-on TZDs improves glycemic control but also increases direct medical cost. In terms of the incremental medical costs associated with these clinical benefits, add-on rosiglitazone or pioglitazone are similar in Taiwan.
Key words: thiazolidinediones (TZDs), cost-effectiveness, incremental cost-effectiveness ratio (ICER), diabetes mellitus, national health insurance