Anticoagulation prophylaxis practice patterns in patients having total hip, total knee replacement in a US health plan

This study aims to illuminate anticoagulation prophylaxis practice patterns in the United States after total joint replacement surgery, with specific attention to duration of overlapping therapy for patients who are "bridged" from low-molecular-weight heparin (LMWH) to warfarin. A large hospital drug database and linked outpatient files were retrospectively analyzed and compared for demographic, clinical, and provider characteristics. Of 2,280 enrollees, 1,770 met eligibility criteria, 1,551 received anticoagulant prophylaxis, 692 received only LMWH, and 595 received only warfarin. Of patients who were bridged from one agent to the other, 94% had less than 5 days of overlap. Each day of overlapping prophylaxis was associated with a 0.857 times decreased risk-adjusted incidence rate of thromboembolic events. Rates were 0.957 times lower for major bleeding and 0.895 times lower for minor bleeding for each day of overlap. In this analysis, longer duration of overlapping therapy is associated with decreased adverse event rates of both venous thromboembolism and bleeding. (Formulary. 2011;46:486-500.)