Cost-effectiveness of oral anticoagulants versus aspirin in patients afterinfrainguinal bypass grafting surgery

Purpose. Several antithrombotic therapies are available for the treatment o f patients with peripheral vascular diseases. It is unknown how quality of life and costs of treatment are influenced by different therapies. This stu dy assessed the cost-effectiveness of oral anticoagulants versus aspirin in patients after infrainguinal bypass grafting surgery. Methods: Clinical ou tcome events and event-free survival were collected from 2650 patients in 7 7 centers who participated in the Dutch Bypass Oral anticoagulants or Aspir in trial. Approximately half the patients had critical ischemia; 60% receiv ed vein grafts, and 20% had femorocrural bypass grafts. A model that was pr imarily driven by clinical outcome events was used as a means of determinin g quality of life (EuroQol EQ-5D) and costs for each patient. The main outc ome measure was the incremental health care costs in relation to the additi onal number of quality-adjusted life years and the additional number of eve nt-free years. Results: The mean costs during the 21 months of follow-up were 6875 per pat ient in the oral anticoagulants group versus 7072 in the aspirin group (dif ference, 197; 95% CI, -746 to 343). The event-free survival was 1.10 years in the group treated with oral anticoagulants versus 1.09 years in the grou p treated with aspirin (difference, 0.01; 95% CI, -0.07 to 0.08), whereas t he corresponding quality-adjusted life years were 1.06 and 1.05, respective ly (difference, 0.01; 95% CI, -0.03 to 0.06). Conclusion: Health care costs, event-free survival, and quality-adjusted li fe years in patients after infrainguinal bypass surgery were not different in patients treated with aspirin and patients treated with oral anticoagula nts. The extra costs of monitoring patients treated with oral anticoagulaut s were limited and play no role in the decision for treatment.