Inpatient compliance with venous thromboembolism prophylaxis after orthopaedic trauma: results from a randomized controlled trial of aspirin versus low molecular weight heparin

Objectives:To compare inpatient compliance with venous thromboembolism prophylaxis regimens.Design:A secondary analysis of patients enrolled in the ADAPT (A Different Approach to Preventing Thrombosis) randomized controlled trial.Setting:Level I trauma center.Patients/Participants:Patients with operative extremity or any pelvic or acetabular fracture requiring venous thromboembolism prophylaxis.Intervention:We compared patients randomized to receive either low molecular weight heparin (LMWH) 30 mg or aspirin 81 mg BID during their inpatient admission.Main Outcome Measurements:The primary outcome measure was the number of doses missed compared with prescribed number of doses.Results:A total of 329 patients were randomized to receive either LMWH 30 mg BID (164 patients) or aspirin 81 mg BID (165 patients). No differences observed in percentage of patients who missed a dose (aspirin: 41.2% vs LMWH: 43.3%, P = .7) or mean number of missed doses (0.6 vs 0.7 doses, P = .4). The majority of patients (57.8%, n = 190) did not miss any doses. Missed doses were often associated with an operation.Conclusions:These data should reassure clinicians that inpatient compliance is similar for low molecular weight heparin and aspirin regimens.