Introduction: Patients undergoing major orthopedic surgery face considerable risk of venous thromboembolism (VTE), which may be fatal unless they receive prophylactic treatment. Fondaparinux sodium is a new antithrombotic agent that is indicated for prophylaxis of VTE after major orthopedic surgery. This paper presents a cost-effectiveness analysis of fondaparinux sodium and enoxaparin sodium, the latter being the most commonly used agent for prophylaxis of VTE.
Methods: The analysis is based on an international simulation model, using Norwegian unit costs, and Norwegian data of 55 000 patients undergoing orthopedic surgery between 1999 and 2001. We estimated the expected incidence of VTE and VTE-related deaths, and expected costs of VTE-related care for each of the two prophylactic agents for different periods.
Results and conclusion: The results indicate that fondaparinux sodium is likely to be more effective than enoxaparin sodium in preventing the incidence of VTE. By day 90, fondaparinux sodium is expected to avoid 180 more VTE events, and between 8 and 33 more VTE-related deaths per 10,000 patients than enoxaparin sodium. Fondaparinux sodium is also a cost-saving option in short follow-up periods for hip fracture surgery. For extended follow-up periods (i.e. 5 years), fondaparinux sodium is also likely to represent the lower cost treatment option after total knee and hip replacement. The sensitivity analyses show that the main results are robust to changes in the most important parameters. Results are, however, sensitive to the price difference between the two drugs.