Is Aspirin a Cost-Effective Thromboprophylaxis Alternative for Orthopaedic Trauma Patients?

University Of Maryland Baltimore, Baltimore MD

Investigators

Abstract

ABSTRACT Orthopaedic trauma affects 1 million Americans annually and is a strong risk factor for venous thromboembolism (VTE) due to the initial injury, surgical intervention, and postoperative immobilization. The treatment of VTE, which includes deep vein thrombosis (DVT) and pulmonary embolism (PE), is associated with costly medical interventions, extended inpatient duration, hospital readmission, and high fatality rates. Currently, all major clinical guidelines recommend a multiweek course of low-molecular-weight heparin (LMWH, enoxaparin) to prevent VTE after orthopaedic trauma. However, our study team recently published a trial in the New England Journal of Medicine that compared thromboprophylaxis with LMWH versus aspirin in over 12,000 patients who sustained orthopaedic trauma. We found that aspirin was noninferior to LMWH in preventing fatal events and similar in its protection against PE and major bleeding events. In contrast, LMWH provided better protection against DVT. Given the substantially lower cost of aspirin for thromboprophylaxis compared to LMWH, determining if LMWH or aspirin is more cost-effective is of tremendous interest to patients, clinicians, payers, and policymakers. In this proposed study, we aim to 1) generate evidence on the comparative costs and effects of LMWH versus aspirin for the prevention of VTE after orthopaedic trauma and 2) determine the cost-effectiveness of LMWH versus aspirin for thromboprophylaxis in orthopaedic trauma patients. We will combine clinical trial data of over 12,000 patients with Truven MarketScan and federal drug pricing data to estimate intervention and treatment costs. In addition, we will estimate health state utilities (HSU) of discrete health states associated with our study outcomes (death, PE, DVT, bleeding) through a systematic literature review of clinical studies with health-related quality of life data. With these data, we will perform a cost-utility analysis (CUA), based on a de novo Markov model, from the US healthcare sector payers’ perspectives. In addition to a base model, we will explore heterogeneity through subgroup estimates based on policy-relevant indicators (age, insurance status, VTE risk, and race). In all models, we will compute the total costs and QALYs expected from each treatment and subgroup. With these, incremental cost-effectiveness ratios (ICERs) of LMWH compared to aspirin using total costs and QALYs accumulated from each treatment. In the base case, we will compare the computed ICER to a standard willingness to pay (WTP) threshold of $100,000 per QALY to assess cost-effectiveness. We will also estimate the value-based prices of LMWH to discern the difference between current market prices and value-based prices at various WTP thresholds. The proposed research is directly relevant to improving patient safety and making healthcare more affordable.