Table 1.
Patient characteristics by prophylaxis type allocated
| Characteristic | Enoxaparin (n = 707) | Aspirin (n = 632) | p value |
| Age in years, mean ± SD | 67 ± 10 | 67 ± 10 | 0.58 |
| Male sex, % (n) | 43 (302) | 36 (227) | 0.01 |
| BMI in kg/m2, mean ± SD | 32 ± 7 | 32 ± 7 | 0.48 |
| ASA classification, % (n)a | |||
| 1 | 6 (42) | 4 (25) | 0.20 |
| 2 | 47 (334) | 50 (313) | |
| 3 | 45 (319) | 45 (289) | |
| 4 | 0.3 (2) | 1 (5) | |
| Diabetes, n (%) | 16 (110) | 19 (118) | 0.15 |
| Current smoker, % (n) | 4 (30) | 4 (24) | 0.78 |
| Inflammatory arthritis, % (n) | 3 (18) | 3 (20) | 0.61 |
| Liver disease, % (n) | 3 (21) | 3 (19) | 1.0 |
| Heart disease, % (n) | 18 (130) | 20 (128) | 0.43 |
| Preoperative anticoagulation, % (n) | |||
| Aspirin | 12 (83) | 16 (101) | 0.008 |
| Other single antiplatelet | 2 (17) | 1 (9) | |
| Dual antiplatelet | 1 (4) | 2 (12) | |
| Direct oral anticoagulant | 5 (38) | 7 (47) | |
| Warfarin | 0.4 (3) | 1 (4) | |
| Type of arthroplasty, % (n) | |||
| THA | 36 (255) | 29 (182) | 0.006 |
| TKA | 64 (452) | 71 (450) | |
| Indication for primary arthroplasty, % (n) | |||
| Osteoarthritis | 89 (628) | 94 (593) | 0.07 |
| Avascular necrosis | 2 (17) | 2 (10) | |
| Inflammatory arthropathy | 2 (11) | 2 (11) | |
| Other | 7 (51) | 3 (18) | |
| Revision, % (n) | 4 (30) | 2 (13) | 0.03 |
| Tourniquet use, % (n) | 57 (405) | 58 (369) | 0.01 |
| Tourniquet time in minutes (TKA only), mean ± SD | 31 ± 33 | 37 ± 35 | 0.002 |
| Tranexamic acid, % (n) | 90 (638) | 91 (574) | 0.49 |
| Closure, % (n) | |||
| Staples | 38 (266) | 67 (423) | < 0.001 |
| Subcuticular | 62 (441) | 33 (209) |
aData missing for 10 patients within the enoxaparin group.
ASA = American Society of Anesthesiologists.