Please see https://drive.google.com/drive/folders/1WD618wrywYjEaXzfLTcuK-VCcnb6b-gV for full code and algorithm definitions.  Inclusion Criteria:  At least 18 years of age Scheduled to undergo elective total hip arthroplasty  Exclusion Criteria:  Scheduled to undergo staged, bilateral hip arthroplasty [Day -30, Day 0] Pregnany or breastfeeding [Day -180, Day 0] Had active bleeding or high risk of bleeding [Day -180, Day 0] Had conditions preventing bilateral venography [Day -30, Day 0] Congestive heart failure [Day -180, Day 0] Pulmonary hypertension [Day -180, Day 0] Edema of legs [Day -180, Day 0] Substantial liver disease [Day -180, Day 0] Severe renal impairment (creatinine clearance <30 ml per minute) [Day -180, Day 0] Concomitant use of protease inhibitors for the treatment of HIV [Day -180, Day 0]