Factors associated with perioperative blood transfusion after primary unilateral TKR
| Variable | aOR (95% CI)* | p Value | |
| Type of anaesthesia | GA | REF | |
| RA | 0.57 (0.37 to 0.87) | 0.009 | |
| Duration of operation (minutes) | ≤100 | REF | |
| >100 | 1.89 (1.14 to 3.14) | 0.014 | |
| Repeat operation within hospital stay | 16.51 (2.22 to 123.04) | 0.006 | |
| Anaemia | None | REF | |
| Mild | 4.13 (2.54 to 6.71) | <0.001 | |
| Moderate/severe | 9.13 (5.34 to 15.61) | <0.001 | |
| ASA-PS score | 1 | REF | |
| 2 | 2.08 (0.63 to 6.90) | 0.23 | |
| 3 | 4.00 (1.05 to 15.21) | 0.042 | |
| CCF | 7.71 (2.24 to 26.53) | 0.001 |
*Adjusted for all the variables listed in table 1.
aOR, adjusted OR; ASA-PS, American Society of Anesthesiologist Physical Status; CCF, congestive cardiac failure; GA, general anaesthesia; RA, regional anaesthesia; REF, reference; TKR, total knee replacement.