Enoxaparin for thromboprophylaxis after major trauma: potential cost implications.
OBJECTIVE
To determine the cost-effectiveness of enoxaparin compared with low-dose-heparin (LDH) for thromboprophylaxis after major trauma and to assess the economic significance of major bleeding as a complication of the use of low-molecular-weight heparin (LMWH).


METHODS
Decision model analysis of the cost and efficacy of enoxaparin at preventing venous thromboembolism (VTE) and the risk and costs of major hemorrhage related to LMWH. The primary outcome was deep vein thromboses (DVTs) averted. Model estimates were based on data from prospective trials of LMWH and other studies of the financial ramifications of DVT and pulmonary embolism.


METHODS
Hypothetical cohort of 1,000 critically ill trauma patients requiring thromboprophylaxis.


METHODS
In the model, patients were managed with either LMWH or LDH.


RESULTS
The marginal cost-effectiveness of enoxaparin was calculated as the savings resulting from cases of DVT averted less the additional costs of both 1) LMWH and 2) major bleeding. This result is expressed as cost (or savings) per DVT prevented. Sensitivity analysis of the impact of the major clinical inputs on the cost-effectiveness was performed. The base case assumed that the incidence of DVT with LDH was 14.7%, that LMWH resulted in a relative risk reduction of DVT of 50%, but that enoxaparin nearly quadrupled the risk of bleeding. Despite the higher costs of enoxaparin, this tactic yielded a net savings of $391.23 per DVT prevented. For sensitivity analysis, model inputs were adjusted by 25% individually and then simultaneously. This demonstrated the model to be most sensitive to the calculated cost of a DVT. With the efficacy of LMWH reduced by 25% of the base-case estimate, enoxaparin resulted in a cost of $311.77 per DVT avoided. When all variables were skewed against LMWH, total outlays were trivial (approximately $85 per patient in the cohort). Neither the rate of increased bleeding with LMWH nor the costs incurred as a result of bleeding significantly altered the model's financial outcomes.


CONCLUSIONS
Reliance on enoxaparin represents a strategy for the prevention of VTE after trauma that may result in savings. Neither concerns about the higher cost of enoxaprin relative to LDH nor the financial implications of major bleeding should preclude the use of LWMH for thromboprophylaxis in trauma patients. Further studies are warranted to confirm the efficacy of enoxaparin.
Shorr
A F
AF
Pulmonary and Critical Care Medicine Service, Department of Medicine, Walter Reed Army Medical Center, Washington, DC, USA.
Ramage
A S
AS
D000925:Anticoagulants / Q000191:economics / Q000627:therapeutic use*; D003362:Cost-Benefit Analysis; D003657:Decision Making; D017984:Enoxaparin / Q000191:economics / Q000627:therapeutic use*; D006495:Heparin, Low-Molecular-Weight / Q000191:economics / Q000627:therapeutic use*; D006801:Humans; D020246:Venous Thrombosis / Q000191:economics / Q000209:etiology / Q000517:prevention & control*; D014947:Wounds and Injuries / Q000150:complications
D000925:Anticoagulants; D017984:Enoxaparin; D006495:Heparin, Low-Molecular-Weight