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.