Cost-effectiveness of fondaparinux compared with enoxaparin as prophylaxis against venous thromboembolism in patients undergoing hip fracture surgery

Objective: To evaluate the cost-effectiveness of fondaparinux relative to enoxaparin as prophylaxis against venous thromboembolism (VTE) in patients undergoing hip fracture surgery. Methods: A decision analysis model was created to simulate the impact of fondaparinux 2.5 mg once daily relative to enoxaparin 30 mg twice daily on patient outcomes and costs over various time points up to 5 years after surgery. Probabilities for the analysis were estimated for a hypothetical cohort of 1000 patients undergoing hip fracture surgery in the United States receiving either fondaparinux or enoxaparin according to comparative trial results. Resource use and costs (2003 dollars) were obtained from large healthcare databases. Outcome measures were rates of symptomatic VTE events, health-care costs, and incremental cost-effectiveness ratios. Results: Fondaparinux is estimated to prevent an additional 30 VTE events (per 1000 patients) at 3 months compared with enoxaparin, producing savings of $103 at discharge, $290 over 1 month, $361 over 3 months, and $466 over 5 years. The results remain robust to clinically plausible variation in input parameters and assumptions. Conclusions: Fondaparinux improves outcomes and is costsaving over a broad range of assumptions compared with enoxaparin for prophylaxis of VTE after hip fracture surgery.