Study flow diagram. A total of 2069 patients (n = 1244 for TKA and n = 825 for THA) were ultimately eligible, after patients with no postoperative blood samples available or samples taken on or before POD 7 (n = 50 for TKA and n = 43 for THA) were excluded. Approximately half of the patients received postoperative pharmacologic thromboprophylaxis with UFH, LMWH (enoxaparin), fondaparinux, or an antiplatelet drug. The other half received only mechanical thromboprophylaxis, either dynamic (intermittent plantar compression device [foot pump] or IPCD) or static (GCSs), or both. #, Postoperative thromboprophylaxis for each patient was at the treating physician’s discretion, according to his or her usual clinical practice; *, the proportion of patients excluded from the analysis due to postoperative samples being unavailable or taken on or before POD 7 in each treatment group; J-PSVT, Japanese Clinical Study of Prevention and Actual Situation of Venous Thromboembolism After Total Arthroplasty (multicenter, prospective cohort).