OBJECTIVES: Both clopidogrel and aspirin have been shown to reduce the risk of recurrent cardiovascular events in various subgroups of patients with vascular disease. This study aims to assess the cost-effectiveness of clopidogrel versus aspirin for high-risk subgroup patients with established peripheral arterial disease (PAD) in China (definition of high-risk: (i) patients with pre-existing symptomatic atherosclerotic disease, or (ii) patients with multi-vascular territory involvement).

METHODS: A life-time Markov model was developed from a third-party payers’ perspective. The model distinguished the following ischaemic events: myocardial infarction (MI), ischemic stroke (IS) and death (due to fatal events or other causes). Subsequent events could be a second MI, a second stroke, a stroke after an MI, an MI after a stroke or death. Finally, patients can experience a third ischaemic event or die. Risks of ischaemic events in the overall PAD patients and relative risks of high-risk subgroup vs overall PAD patients were from CAPRIE trial. Drug acquisition cost, other direct medical costs, and utilities were from pricing records and literatures. The model calculated incremental cost and quality-adjusted life years (QALYs) and incremental cost-effectiveness ratio (ICER). Sensitivity analyses were conducted.

RESULTS: In the type (i) high-risk population, the total costs of clopidogrel and aspirin arms were ¥18,776.54 and ¥12,301.72, respectively; the total QALYs were 8.7761 and 8.5761, respectively. The ICER of clopidogrel over aspirin was ¥32,381.82 per QALY gained. In the type (ii) high-risk population, the total costs of clopidogrel and aspirin arms were ¥18,517.56 and ¥12,041.41, respectively; the total QALYs were 8.8360 and 8.6319, respectively. The ICER was ¥31,742.72 per QALY gained. In both groups of high-risk populations, the ICERs were lower than recommended cost-effectiveness threshold (3xGDP/capita, ¥161,940). Both one-way, and probabilistic sensitivity analyses confirmed the robustness of the results.

CONCLUSIONS: Compared with aspirin, clopidogrel was more cost-effective among high-risk patients with established PAD in China.