Table 2.
Patient characteristics and outcomes in intervention and control groups at baseline (unadjusted)
| Characteristic | Intervention (n = 924) | Control (n = 1040) | p value |
|---|---|---|---|
| Joint, % knee | 417 (45%) | 485 (47%) | 0.50 |
| Age, years | 69.3 (SD 10.0) | 70.1 (SD 9.5) | 0.053 |
| Gender, % female | 616 (67%) | 708 (68%) | 0.51 |
| BMI, kg/m2 | 28.6 (SD 4.8) | 28.7 (SD 4.9) | 0.68 |
| Smoking, % | 128 (10%) | 90 (13%) | 0.047 |
| Physical status classificationa | 0.001 | ||
| • % ASA 1 | 164 (18%) | 201 (20%) | |
| • % ASA 2 | 631 (71%) | 653 (64%) | |
| • % ASA 3–4 | 97 (11%) | 170 (17%) | |
| Preoperative Hb, g/dl | 13.8 (SD 1.2) | 13.8 (SD 1.2) | 0.30 |
| Use of LIA, % | 184 (20%) | 221 (21%) | 0.54 |
| Use of TXA, % | 213 (24%) | 190 (18%) | 0.001 |
| Type of anesthesia, % general anesthesia | 302 (33%) | 295 (28%) | 0.038 |
| Use of blood salvage | 275 (30%) | 556 (54%) | <0.001 |
| Use of EPO (in EPO eligible patients) | 62 (29%) | 132 (51%) | <0.001 |
| Postoperative Hb, g/dl | 11.2 (SD 1.4) | 11.2 (SD 1.4) | 0.40 |
| Length of stay | 4.2 (SD 2.9) | 3.8 (SD 1.8) | <0.001 |
| Allogeneic transfusion, % | 79 (8.5%) | 62 (6.0%) | 0.027 |
| Number of RBC units transfused (in transfused patients) | 2.5 (SD 1.44) | 2.2 (SD 0.87) | 0.093 |
aDue to the small number of ASA 4 patients (n = 1), ASA 3 and 4 are combined