Thromboembolism prophylaxis in medical inpatients: Effect on outcomes and costs

Objectives: To evaluate the real-world use of venous thromboembolism (VTE) prophylaxis among medical inpatients and the impact of VTE prophylaxis on outcomes and cost. Study Design: Retrospective analysis of patientlevel administrative claims data for medical inpatients at risk of VTE and linked outpatient data. Methods: Data were analyzed from patients admitted to the hospital from 2005 to 2007 (calendar years) with a primary diagnosis of chronic heart failure, thromboembolic stroke, severe lung disease, acute infection, or cancer (index hospitalization), according to whether they received VTE prophylaxis or not. The number of VTE events, time to VTE event, length of hospital stay, and number of major or minor bleeding events were analyzed from the index date until the end of follow-up (180 days postdischarge) or death. Results: Overall, 7127 of 13,293 patients (53.6%) received VTE prophylaxis. Prophylaxis significantly reduced the incidence of VTE compared with no prophylaxis (0.06% vs 3.44%, respectively; P <.00001) and increased the median time to VTE (182 vs 27 days, respectively). Prophylaxis also significantly reduced the incidence of VTE in the 180 days postdischarge. Readmission rates were similar between groups. Major bleeding occurred in 1.57% of patients receiving low molecular weight heparin + warfarin versus <.6% receiving any other form of prophylaxis. The development of VTE or major or minor bleeding events significantly increased total medical costs versus no VTE events (P <.0001) or no bleeding events (P <.0003). Conclusions: This real-world analysis showed that thromboprophylaxis was underutilized in medical patients, even though the clinical and economic impact of VTE was significant.