1. Japanese National Hospital Organization (NHO)–Evidence-Based Medicine Study Group for the Clinical Study of Prevention and Actual Situation of Venous Thromboembolism After Total Arthroplasty, Tokyo, Japan;
2. Division of Clinical Epidemiology, NHO Tokyo Medical Center, Tokyo, Japan;
3. Division of Transfusion Medicine, National Cerebral and Cardiovascular Center, Osaka, Japan;
4. Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, Mie, Japan;
5. Department of Anesthesiology, National Cerebral and Cardiovascular Center, Osaka, Japan; and
6. Department of Orthopedic Surgery, NHO Nagasaki Medical Center, Nagasaki, Japan