Cost-effectiveness of prophylactic anticoagulation prolonged after hospital discharge following general surgery

F. P. Sarasin and H. Bounameaux
Department of Internal Medicine, Hopital Cantonal Universitaire, Geneva, Switzerland.

OBJECTIVE: To evaluate the net clinical benefit and the economic burden of prophylactic anticoagulation prolonged after hospital discharge following general surgery. DESIGN: A cost-effective analysis representing the risks of developing symptomatic venous thromboembolism beyond the hospital stay, the risks of major bleeding, and the efficacy of treatment. Data were drawn from the literature. SUBJECTS: A hypothetical cohort of 10,000 patients discharged from the hospital after general surgery (gastrointestinal, gynecologic, urologic, or vascular surgery). INTERVENTIONS: We compared 2 strategies: (1) prolonged self-administered prophylactic low-dose low-molecular-weight heparin during 4 weeks after discharge from the hospital and (2) anticoagulant therapy with heparin started immediately after the first clinically overt venous thromboembolism. MAIN OUTCOME MEASURES: The number of venous thromboembolisms prevented, the number of major bleeding events induced, and the average direct costs. RESULTS: Prophylactic low-molecular-weight heparin was an effective therapy. Depending on the rate of venous thromboembolism (0.06% to 0.18% per week), this strategy prevented 19 to 58 venous thromboembolisms for a cohort of 10,000 patients treated, more than the number of anticoagulation-related complications (n = 10). Its marginal costs, however, exceeded $2.5 million (US dollars) for 10,000 patients. As the weekly rate of venous thromboembolism increased, prophylactic low-molecular-weight heparin became more cost-effective, with a marginal cost-effectiveness ratio per venous thromboembolism prevented ranging from $135,903 (rate of venous thromboembolism, 0.06% per week) to 45,353 (rate of venous thromboembolism, 0.18% per week). CONCLUSION: Although prolonged prophylactic anticoagulation after hospital discharge for general surgery is effective in preventing venous thromboembolism, we believe that its marginal costs are too high to recommend its indiscriminate use.