PCV1: A COST-EFFECTIVENESS ANALYSIS OF CLOPIDOGREL VERSUS ASPIRIN AS PREVENTION OF ISCHEMIC EVENTS IN PATIENTS WITH ESTABLISHED PERIPHERAL ARTERY DISEASE

Abstract

OBJECTIVES: Since becoming widely recognized for its antithrombotic effects in the 1970s, aspirin has become first-line antiplatelet therapy across most patient populations. However, newer data suggests that clopidogrel is more effective than aspirin for prevention of ischemic events in peripheral artery disease (PAD) patients. In this analysis, a decision analytic model was constructed in order to evaluate the cost-effectiveness of clopidogrel versus aspirin as prevention of ischemic events in patients with established PAD. METHODS: Data on the probability of ischemic events was extracted from the PAD subgroup of the CAPRIE trial, in which event rates for clopidogrel and aspirin were 3.71% and 4.86%, respectively. Costs included in this analysis were obtained from the medical literature. RESULTS: In the base case analysis, the expected cost of treatment over a one-year time frame with clopidogrel and aspirin was $2075 and $1088, respectively. Furthermore, to effectively treat one patient, it would cost $2155 with clopidogrel and $1144 with aspirin. An incremental cost-effectiveness analysis concluded that one additional event of vascular death, MI, or ischemic stroke will be prevented with clopidogrel at an additional one-year cost of $85,826. A univariate sensitivity analysis demonstrated that aspirin must have ischemic event rates greater than 13% for clopidogrel to be the preferred option based solely on cost. Furthermore, in order for clopidogrel to be considered cost-effective with an event rate of 3.71%, aspirin must have an event rate of 11.48%, a rate 2.4 times greater than was observed in the CAPRIE trial. CONCLUSIONS: The result of this analysis concluded that it would cost a third-party payer an extra $85,826 to effectively treat one additional patient over a one-year period when using clopidogrel instead of aspirin. This cost can play a major role in the decision of appropriate antiplatelet therapy used to treat PAD patients in the prevention of ischemic events.