Table 1.
Baseline characteristics of participants.
| BMI (quartile) | Q1 (11.21-24.10) | Q2 (24.10-27.58) | Q3 (27.58-31.90) | Q4 (31.91-48.90) | P value |
|---|---|---|---|---|---|
| N | 4410 | 4441 | 4429 | 4433 | |
| Sex N (%) | <0.001 | ||||
| Male | 1714 (38.9%) | 2359 (53.1%) | 2397 (54.1%) | 1923 (43.4%) | |
| Female | 2696 (61.1%) | 2082 (46.9%) | 2032 (45.9%) | 2510 (56.6%) | |
| Race, N (%) | <0.001 | ||||
| White | 3094 (70.2%) | 3209 (72.3%) | 3347 (75.6%) | 3354 (75.7%) | |
| Asian | 243 (5.5%) | 174 (3.9%) | 77 (1.7%) | 42 (0.9%) | |
| African American | 256 (5.8%) | 246 (5.5%) | 293 (6.6%) | 408 (9.2%) | |
| Unknown | 817 (18.5%) | 812 (18.3%) | 712 (16.1%) | 629 (14.2%) | |
| Age range, N (%) | <0.001 | ||||
| 18-40 | 894 (20.3%) | 716 (16.1%) | 615 (13.9%) | 713 (16.1%) | |
| 41-60 | 1722 (39.0%) | 1785 (40.2%) | 1807 (40.8%) | 2042 (46.1%) | |
| 61-80 | 1633 (37.0%) | 1747 (39.3%) | 1849 (41.7%) | 1613 (36.4%) | |
| > 81 | 161 (3.7%) | 193 (4.3%) | 158 (3.6%) | 65 (1.5%) | |
| Serum sodium (Mean ± SD) | 138.4 ± 3.3 | 138.6 ± 3.1 | 138.7 ± 3.1 | 138.9 ± 3.0 | <0.001 |
| Blood urea nitrogen (Mean ± SD) | 16.8 ± 7.8 | 17.5 ± 7.8 | 17.8 ± 7.7 | 17.6 ± 8.5 | <0.001 |
| White blood cell count (Mean ± SD) | 9.2 ± 4.4 | 9.4 ± 4.4 | 9.6 ± 4.4 | 9.7 ± 4.4 | <0.001 |
| Hematocrit (Mean ± SD) | 39.3 ± 4.8 | 40.6 ± 4.7 | 40.9 ± 4.6 | 40.6 ± 4.6 | <0.001 |
| Platelet count (Mean ± SD) | 250.7 ± 81.6 | 239.8 ± 74.0 | 238.7 ± 70.4 | 245.7 ± 73.5 | <0.001 |
| Duration of operation (Mean ± SD) | 202.2 ± 124.7 | 209.2 ± 134.0 | 214.6 ± 131.6 | 227.6 ± 136.1 | <0.001 |
| Diabetes, N (%) | <0.001 | ||||
| No | 4163 (94.4%) | 4058 (91.4%) | 3897 (88.0%) | 3547 (80.0%) | |
| Yes (Noninsulin-dependent) | 162 (3.7%) | 247 (5.6%) | 336 (7.6%) | 546 (12.3%) | |
| Yes (Insulin-dependent) | 85 (1.9%) | 136 (3.1%) | 196 (4.4%) | 340 (7.7%) | |
| Smoking status, N (%) | <0.001 | ||||
| No | 3261 (73.9%) | 3624 (81.6%) | 3661 (82.7%) | 3734 (84.2%) | |
| Yes | 1149 (26.1%) | 817 (18.4%) | 768 (17.3%) | 699 (15.8%) | |
| Ventilator dependence, N (%) | 0.067 | ||||
| No | 4362 (98.9%) | 4396 (99.0%) | 4372 (98.7%) | 4401 (99.3%) | |
| Yes | 48 (1.1%) | 45 (1.0%) | 57 (1.3%) | 32 (0.7%) | |
| Severe COPD, N (%) | <0.001 | ||||
| No | 4120 (93.4%) | 4285 (96.5%) | 4251 (96.0%) | 4264 (96.2%) | |
| Yes | 290 (6.6%) | 156 (3.5%) | 178 (4.0%) | 169 (3.8%) | |
| Congestive heart failure, N (%) | 0.023 | ||||
| No | 4396 (99.7%) | 4432 (99.8%) | 4420 (99.8%) | 4410 (99.5%) | |
| Yes | 14 (0.3%) | 9 (0.2%) | 9 (0.2%) | 23 (0.5%) | |
| Hypertension, N (%) | <0.001 | ||||
| No | 3330 (75.5%) | 2934 (66.1%) | 2535 (57.2%) | 2177 (49.1%) | |
| Yes | 1080 (24.5%) | 1507 (33.9%) | 1894 (42.8%) | 2256 (50.9%) | |
| Renal failure, N (%) | 0.057 | ||||
| No | 4409 (100.0%) | 4441 (100.0%) | 4424 (99.9%) | 4428 (99.9%) | |
| Yes | 1 (0.0%) | 0 (0.0%) | 5 (0.1%) | 5 (0.1%) | |
| Disseminated cancer, N (%) | <0.001 | ||||
| No | 3146 (71.3%) | 3542 (79.8%) | 3572 (80.7%) | 3673 (82.9%) | |
| Yes | 1264 (28.7%) | 899 (20.2%) | 857 (19.3%) | 760 (17.1%) | |
| Open wound infection, N (%) | 0.221 | ||||
| No | 4369 (99.1%) | 4408 (99.3%) | 4400 (99.3%) | 4388 (99.0%) | |
| Yes | 41 (0.9%) | 33 (0.7%) | 29 (0.7%) | 45 (1.0%) | |
| Steroid use, N (%) | 0.058 | ||||
| No | 3741 (84.8%) | 3797 (85.5%) | 3708 (83.7%) | 3792 (85.5%) | |
| Yes | 669 (15.2%) | 644 (14.5%) | 721 (16.3%) | 641 (14.5%) | |
| Preoperation transfusions, N (%) | 0.600 | ||||
| No | 4391 (99.6%) | 4427 (99.7%) | 4417 (99.7%) | 4419 (99.7%) | |
| Yes | 19 (0.4%) | 14 (0.3%) | 12 (0.3%) | 14 (0.3%) | |
| Emergency case, N (%) | <0.001 | ||||
| No | 4131 (93.7%) | 4218 (95.0%) | 4201 (94.9%) | 4274 (96.4%) | |
| Yes | 279 (6.3%) | 223 (5.0%) | 228 (5.1%) | 159 (3.6%) | |
| 30 day mortality events, N (%) | 117 (2.65%) | 91 (2.05%) | 115 (2.60%) | 100 (2.26%) | 0.021 |