Cost Savings of Switching to Aspirin for Thromboprophylaxis in Orthopaedic Trauma Patients: A Budget Impact Analysis

Introduction: Clinical guidelines recommend low-molecular-weight heparin (enoxaparin) to prevent venous thromboembolism in orthopaedic trauma patients. However, a large trial recently found aspirin noninferior to enoxaparin in preventing death and pulmonary embolism in this population. We modeled cost implications for the United States healthcare system if aspirin replaced enoxaparin as the standard of care for thromboprophylaxis in orthopaedic trauma patients. Methods: The modeling compared spending under two scenarios: continued use of enoxaparin versus switching to aspirin. The model included fracture incidence estimates from the National Inpatient Sample and dose and duration data from the clinical trial. We derived medication costs from current market prices across payer types and care settings (ie, inpatient and postdischarge prescriptions). The model incorporates uncertainty around each parameter based on calculated standard errors and generates bootstrapped estimates of costs and cost savings disaggregated by the payer. Results: The results indicated that prescribing enoxaparin for thromboprophylaxis to more than 600,000 fracture patients costs $162.7 million annually, whereas thromboprophylaxis with aspirin would cost $1.6 million annually. Spending on thromboembolic events totals $210.7 million under the enoxaparin scenario and $222.1 million with aspirin. Overall, aspirin for thromboprophylaxis in fracture patients would yield annual savings of $149.7 million (95% credible interval: $97 to $208 million) compared with enoxaparin. Conclusion: Our findings suggest that a widespread switch from enoxaparin thromboprophylaxis to aspirin would lead to more than $100 million in annual cost savings in the United States alone. Insurers stand to benefit most from this practice change. However, patients, especially those without insurance, would realize considerable savings from aspirin thromboprophylaxis.