Prevention of venous thromboembolism after general surgery. Cost-effectiveness analysis of alternative approaches to prophylaxis.

A number of methods of prophylaxis can reduce the risk of postoperative venous thromboembolism in patients undergoing general surgery. The cost-effectiveness of several of these--low-dose subcutaneous heparin, intermittent pneumatic compression, graduated compression stockings, heparin plus dihydroergotamine, heparin plus stockings, and intermittent pneumatic compression plus stockings--was assessed by pooling data from published reports of randomized controlled trials. Using clinical protocols, costs for prophylaxis, diagnosis, and treatment of venous thromboembolism were determined. The expected outcomes and costs of each strategy were then calculated using techniques of decision analysis. The results indicate that stockings are the only prophylactic method that is actually cost-saving. Costs of care average $34 less per admission for patients using stockings than for those receiving no prophylaxis. Most other methods of prophylaxis further reduce thromboembolic risk, but increase costs by $50 to $88 per patient relative to costs for the use of stockings. Differences in the cost-effectiveness of these prophylaxis are more marked, ranging from about $50,000 to almost $500,000 per additional life saved.