OBJECTIVES: To determine the incremental cost-effectiveness in Taiwan of clopidogrel versus aspirin in secondary prevention of atherothrombotic events (myocardial infarction (MI), ischemic stroke (IS), vascular death) in 4 high-risk populations: patients with prior CABG, prior MI or IS, with diabetes and/or hypercholesterolemia and polyvascular disease, from the CAPRIE randomized clinical trial. METHODS: This economic analysis is based on a published 2-year Markov model (four six-month cycles) from the perspective of the Taiwanese Health care payer. The effectiveness data were derived from the CAPRIE trial for which clopidogrel demonstrated an amplified clinical benefit over ASA in these high-risk populations. Survival data were based on the Saskatchewan Health database; the Taiwanese local costs were obtained from the BNHI database between 2000 and 2002. Direct costs include hospitalizations, outpatient visits and laboratory tests, cardiovascular procedures, concomitant medications and adverse events management. Costs were expressed in Euros. Clinical benefits and costs were discounted at 3% in the base case analysis. Cost-effectiveness was expressed as the cost per Life Year Gained (CLYG). RESULTS: In these populations at higher risk of recurrence of cardiovascular events, clopidogrel produced more LYGs at reasonable incremental costs when compared to CLYG obtained for the overall population (€12,449/LYG). The incremental cost-effectiveness ratio, (ICER) expressed in cost per LYG was €1441 in patients previously undergoing CABG, €5506 in patients with history of MI or IS prior index event, €5530 in patients with diabetes and/or hypercholesterolemia, and €4948 in polyvascular patients. CONCLUSIONS: Analyses using the same model in several European countries found similar decreases in ICER for these high risk populations. Based on this study results, we can conclude that clopidogrel is cost-effective in the secondary prevention of cardiovascular events in patients at high risk of recurrence of further cardiovascular events in Taiwan.  (Source of financial support: This study was supported by a grant from the sanofi-aventis Taiwan.)