Introduction: Fondaparinux, a selective inhibitor of activated factor X, has been shown to reduce further the risk of venous thromboembolism (VTE) in major orthopaedic surgery compared to the low molecular weight heparin enoxaparin, when both were applied for 7 days after surgery.

Aims: To compare the expected costs and clinical outcomes of fondaparinux with enoxaparin applied for 7 days after surgery, we conducted a cost-consequence analysis in patients undergoing major orthopaedic surgery, i.e. total hip replacement, total knee replacement and hip fracture repair.

Methods: Our decision model included endpoints relevant in routine clinical practice and the natural history of VTE over a long term period of 5 years. Costs for prevention, diagnosis and treatment of VTE and its complications were estimated from the Belgian health care payer perspective. Analyses were conducted for different time horizons and for the three indications, separately, and then combined.

Results: Overall, our results indicated that the initial investment in fondaparinux (cost per day: 10.39 Euros versus 3.74 Euros for enoxaparin) was soon compensated by savings due to avoided VTE events, with cost neutrality being achieved after 90 days and further savings being incurred over longer time periods mainly due to avoided post-thrombotic syndromes. These findings were most pronounced in patients undergoing hip fracture repair. Sensitivity analyses showed these findings to be robust for the three indications separately, and combined.

Conclusions: We conclude that our analysis of health and economic consequences over a long term period, demonstrates the value for money of fondaparinux versus enoxaparin for the prevention of VTE events after total hip replacement, total knee replacement and hip fracture repair.

Aims: We conducted an cost-utility analysis to compare standard (in-hospital) with prolonged (out-of-hospital) enoxaparin prophylaxis after elective total hip and knee replacement. Methods: The perspective was that of a societal healthcare payer, taking Belgium as a case country. The main outcome measure was the incremental cost-utility ratio, reported as the incremental cost per quality-adjusted life year gained (Euro/QALY). Costs for diagnosis and treatment of proximal and distal deep vein thrombosis, pulmonary embolism, postphlebitic syndrome, and major bleeding were obtained from a Delphi panel (orthopaedic surgeons) and the official reimbursement rates (Federal Ministery of Health). QALYs for these health states were based on utility scores as reported in the literature. Results: In the base-case analysis, incremental costs of prolonged prophylaxis amounted 58 Euro and 114 Euro per patient, with an additional gain in QALY of 0.0083 and 0.0018 after total hip and knee replacement, respectively. Thus, a strategy of prolonged enoxaparin prophylaxis was associated with a cost-utility ratio of 6,964 Euro/QALY and 64,907 Euro/QALY after total hip and knee replacement, respectively. Applying a societal willingness-to-pay threshold value of 20,000 Euro/QALY, prolonged enoxaparin prophylaxis is cost-effective after elective total hip replacement. Sensitivity analyses confirmed the general robustness of these findings. Conclusions: After elective total hip or knee replacement, prolonged enoxaparin prophylaxis leads to increased effectiveness at increased cost. Nevertheless, given the additional costs healthcare decision makers in Europe are usually prepared to pay for a gain in effectiveness, prolonged prophylaxis with enoxaparin is cost-effective after total hip replacement