Long-term cost-effectiveness of low molecular weight heparin versus unfractionated heparin for the prophylaxis of venous thromboembolism in elective hip replacement.

BACKGROUND AND OBJECTIVE: Either low molecular weight heparin (LMWH) or unfractionated heparin (UH) may be used for the prophylaxis of post-operative venous thromboembolic disease (VTD) in elective hip replacement. This study was aimed at assessing the cost-effectiveness of LMWH over UH from the society perspective, which considers all the outcomes occurring in the life-long time horizon. DESIGN AND METHODS: A decision tree modeled the clinical outcomes and resources used in consequence of restricted (2 weeks) and extended (4 weeks) prophylaxis of VTD with LMWH or UH. RESULTS: In the studied population, that of 67 year-old patients, restricted prophylaxis with LMWH saved 25 quality-adjusted days and $75 over UH. Extended prophylaxis provided a small additional benefit with additional cost savings. The incremental outcomes of the model proved independent of most parameters. INTERPRETATION AND CONCLUSIONS: We conclude that LMWH has considerable advantages over UH in the prophylaxis of VTD following elective hip replacement, and should be recommended in clinical practice.