Table 1.
Comparison of preoperative variables between the two groups
| Transfusion(n = 391) | Non-transfusion(n = 5011) | t/z/χ2 | P | |
|---|---|---|---|---|
| Age, years | 67 (61,72) | 66 (61,71) | 1.656 | 0.098 |
| Sex | 17.307 | 0.000 | ||
| Male | 57 | 1192 | ||
| Female | 334 | 3819 | ||
| BMI, Kg/m2 | 26.04 (23.52,29.14) | 27.34 (24.88,29.69) | 5.292 | 0.000 |
| Duration of disease, years | 11.731 | 0.008 | ||
| <1 | 19 | 251 | ||
| 1–3 | 29 | 562 | ||
| 3–10 | 125 | 1816 | ||
| >10 | 218 | 2382 | ||
| Smoking | 28 | 503 | 3.387 | 0.066 |
| Alcohol | 24 | 553 | 9.119 | 0.003 |
| Allergies | 65 | 754 | 0.701 | 0.402 |
| Transfusion history | 58 | 294 | 47.872 | 0.000 |
| Blood type (Rh) | 0.000 | 1.000 | ||
| Rh+ | 389 | 4990 | ||
| Rh- | 2 | 21 | ||
| Blood type (ABO) | 3.748 | 0.290 | ||
| A | 101 | 1493 | ||
| B | 121 | 1540 | ||
| O | 124 | 1401 | ||
| AB | 45 | 577 | ||
| CCI | 3 (2,3) | 3 (2,3) | 1.065 | 0.287 |
| Indications | 0.155* | |||
| Osteoarthritis | 372 | 4835 | ||
| Rheumatoid arthritis | 16 | 151 | ||
| Traumatic arthritis | 3 | 10 | ||
| Psoriatic arthritis | 0 | 6 | ||
| Others | 0 | 9 | ||
| Procedures | 653.561 | 0.000 | ||
| Bilateral TKA | 231 | 570 | ||
| Unilateral TKA | 160 | 4441 | ||
| TXA use | 130 | 2060 | 9.345 | 0.002 |
| Comorbidities | ||||
| Hypertension | 186 | 2549 | 1.578 | 0.209 |
| Diabetes mellitus | 68 | 801 | 0.532 | 0.466 |
| Coronary heart disease | 67 | 687 | 3.544 | 0.060 |
| Arrhythmia | 9 | 139 | 0.303 | 0.582 |
| Heart failure | 1 | 6 | 0.471* | |
| Other cardiac diseases | 8 | 78 | 0.555 | 0.456 |
| Peripheral vascular disease | 8 | 114 | 0.086 | 0.769 |
| Cerebrovascular disease | 38 | 342 | 4.644 | 0.031 |
| Mental illness | 3 | 45 | 0.070 | 0,791 |
| Pulmonary disease | 9 | 180 | 1.789 | 0.181 |
| Digestive system disease | 22 | 359 | 1.308 | 0.253 |
| Urinary system diseases | 5 | 121 | 2.054 | 0.152 |
| Gynecologic diseases | 12 | 149 | 0.011 | 0.915 |
| Laboratory tests | ||||
| RET, 109/μl | 61 (57,78) | 64 (52,78) | 3.517 | 0.000 |
| MCV, fL | 89.5 (86.4,92.6) | 89.4 (86.7,92.2) | 0.257 | 0.797 |
| MCH, Pg | 29.7 (28.6,30.7) | 29.9 (28.9,30.9) | 2.291 | 0.022 |
| MCHC, g/L | 332.0 (324.0,340.0) | 333.0 (327.0,341.0) | 3.563 | 0.000 |
| Hb, g/L | 80.0 (74.0,91.0) | 105.0 (95.00,115.0) | 23.463 | 0.000 |
| RDW, % | 13.0 (12.5,13.7) | 12.8 (12.4,13.3) | 23.046 | 0.000 |
| PLT, 109/L | 146.0 (121.0,179.0) | 179.0 (149.0,213.0) | 11.825 | 0.000 |
| PDW, fL | 11.7 (10.8,13.2) | 11.8 (10.8,13.0) | 0.452 | 0.651 |
TKA Total knee arthroplasty, BMI Body mass index, CCI Charlson comorbidity index, TXA Tranexamic acid, RET Reticulocyte, MCV Mean corpuscular volume, MCH Mean corpuscular hemoglobin, MCHC Mean corpuscular hemoglobin concentration, Hb Hemoglobin, RDW Red blood cell distribution width, PLT Platelet, PDW Platelet distribution width
*Fisher's exact test