Table 1.
Baseline characteristics for patients receiving a blood transfusion or not during the perioperative period of curative resection for head and neck cancer.
| Original Data | After IPTW | |||||
|---|---|---|---|---|---|---|
| No Transfusion (n = 491) |
Transfusion (n = 192) | SDD | No Transfusion |
Transfusion | SDD | |
| Age | 58 ± 13 | 57 ± 11 | 8.9 | 58 ± 12 | 57 ± 11 | 4.8 |
| Sex, male | 417 (84.9%) | 172 (89.6%) | 14.0 | 560 (86.8%) | 434 (91.3%) | 14.6 |
| BMI, kg·m−2 | 25.0 ± 4.3 | 24.15 ± 3.68 | 21.6 | 24.87 ± 4.18 | 25.22 ± 3.93 | 8.5 |
| ASA physical status > 3 | 112 (22.8%) | 67 (34.9%) | 26.9 | 179 (27.7%) | 175 (36.9%) | 19.8 |
| Smoking | 358 (72.9%) | 151 (78.6%) | 13.4 | 489 (75.8%) | 396 (83.4%) | 19.2 |
| Betel nut chewing | 237 (48.3%) | 138 (71.9%) | 49.7 | 354 (54.8%) | 323 (68.1%) | 27.5 |
| Alcohol | 293 (59.7%) | 123 (64.1%) | 9.0 | 397 (61.5%) | 338 (71.1%) | 20.3 |
| Preoperative haemoglobin, g·dL−1 | 13.9 ± 1.6 | 13.1 ± 1.7 | 48.7 | 13.8 ± 1.7 | 13.5 ± 1.5 | 18.6 |
| Anesthesia time, min * | 8.15 ± 0.97 | 9.67 ± 0.71 | 178.4 | 8.49 ± 1.09 | 8.90 ± 1.14 | 36.8 |
| Blood loss during surgery, mL * | 5.60 ± 2.10 | 8.87 ± 1.48 | 179.9 | 6.33 ± 2.32 | 7.41 ± 2.15 | 48.5 |
| Positive surgical margin | 315 (64.2%) | 113 (58.9%) | 10.9 | 380 (58.8%) | 244 (51.4%) | 14.9 |
| Primary tumour | 117.6 | 15.1 | ||||
| T1 and T2 | 300 (61.1%) | 27 (14.1%) | 408 (63.3%) | 265 (55.9%) | ||
| T3 and T4 | 191 (38.9%) | 165 (85.9%) | 237 (36.7%) | 210 (44.1%) | ||
| Histologic differentiation | 8.1 | 5.6 | ||||
| Well | 213 (43.4%) | 91 (47.4%) | 305 (47.3%) | 238 (50.1%) | ||
| Moderate to severe | 278 (56.6%) | 101 (52.6%) | 340 (52.7%) | 237 (49.9%) | ||
| Lymph node involvement | 127 (25.9%) | 99 (51.6%) | 54.7 | 199 (30.8%) | 183 (38.5%) | 16.1 |
| Adjunct radiotherapy | 181 (36.9%) | 136 (70.8%) | 72.5 | 293 (45.4%) | 228 (48.0%) | 5.1 |
| Adjunct chemotherapy | 143 (29.1%) | 125 (65.1%) | 77.3 | 244 (37.9%) | 207 (43.6%) | 11.7 |
Values were mean ± SD or counts (percent). Standardized difference (SDD) is the difference in mean or proportion divided by the pooled standard error, expressed as a percentage; imbalance is defined as an absolute value greater than 20 (small effect size). IPTW: inverse probability treatment weighting; BMI: body mass index. * On a base-2 logarithmic scale.