An evidence-based cost-effectiveness model on methods of prevention of posttraumatic venous thromboembolism.
BACKGROUND
Venous thromboembolism (VT) after injury is a major health problem. Literature data on methods of VT prophylaxis are not consistent with regard to safety and efficacy, and a recent evidence-based report could not conclude that any method was superior to any other or to no prophylaxis. Because no study exists on the cost-effectiveness (C-E) of the different methods of prophylaxis, data from the evidence-based report were used to design a C-E analysis. This analysis will assist in the design of future randomized trials with adequate power to show significant outcome differences.


METHODS
A decision-tree model was designed on the basis of outcomes from the evidence-based report or relevant literature. We then calculated the cost of prevention of VT by one of the most commonly used methods-low-dose heparin (LDH), low-molecular-weight heparin (LMWH), or sequential compression devices (SCDs)-using different probabilities of incidence of VT. Finally, we adjusted the cost for expected years of life after the episode of VT to calculate the cost per life-year saved by preventing VT.


RESULTS
We produced two tables that can be used to calculate the cost per life-year saved for any patient according to his or her age and the method of prophylaxis used. VT prophylaxis becomes less cost-effective as age progresses, because of decreased life-expectancy. With a widely accepted cost limit of $50,000 per life-year saved to indicate cost-effective treatment, LDH is more cost-effective than LMWH or SCDs.


CONCLUSIONS
Our C-E model can help future investigators plan VT-related research with appropriate sample sizes to evaluate cost-effective methods of prophylaxis. LMWH and SCDs must demonstrate substantial improvements in measured outcomes to be more cost-effective than LDH. C-E must be incorporated as a primary outcome in future studies comparing different methods of VT prophylaxis.
Velmahos
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Department of Surgery, Keck School of Medicine, University of Southern California, Los Angeles 90033, USA. velmahos@hsc.usc.edu
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D000925:Anticoagulants / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use*; D001458:Bandages / Q000191:economics; D003362:Cost-Benefit Analysis; D003663:Decision Trees; D019317:Evidence-Based Medicine; D006493:Heparin / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use*; D006801:Humans; D017059:Models, Econometric; D011655:Pulmonary Embolism / Q000191:economics / Q000209:etiology / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic; D012107:Research Design; D015912:Thrombolytic Therapy / Q000191:economics*; D014481:United States; D026712:Value of Life; D014947:Wounds and Injuries / Q000150:complications*
D000925:Anticoagulants; D006493:Heparin