TABLE 1.
Baseline characteristics unadjusted sample and propensity score‐matched sample.
| Characteristic | Unadjusted sample (N = 223,415) | PSM adjusted (1:1) (N = 119,491) | ||||
|---|---|---|---|---|---|---|
| BMI ≤22.64 (n = 72,851) | BMI > 22.64 (n = 150,564) | SMD | BMI ≤22.64 (n = 59,746) | BMI > 22.64 (n = 59,745) | SMD | |
| Age, years | 48.00 [35.00, 61.00] | 53.00 [44.00, 62.00] | 0.295 | 50.00 [37.00, 62.00] | 50.00 [40.00, 59.00] | 0.013 |
| Female sex (%) | 41,513 (57.0) | 68,399 (45.4) | 0.233 | 32,141 (53.8) | 32,229 (53.9) | 0.003 |
| ASA physical status (%) | ||||||
| Class I | 32,319 (15.1) | 168 (2.1) | 0.158 | 238 (1.6) | 168 (2.2) | 0.119 |
| Class II | 165,421 (77.5) | 5340 (66.7) | 10,582 (69.8) | 5250 (69.3) | ||
| Class III | 15,793 (7.4) | 2500 (31.2) | 4338 (28.6) | 2161 (28.5) | ||
| Class IV | 693 (1.0) | 1181 (0.8) | 603 (1.0) | 309 (0.5) | ||
| Hypertension (%) | 7688 (10.6) | 36,525 (24.3) | 0.368 | 7252 (12.1) | 5637 (9.4) | 0.087 |
| Diabetes (%) | 5941 (8.2) | 21,702 (14.4) | 0.199 | 5432 (9.1) | 5382 (9.0) | 0.003 |
| Coronary heart disease (%) | 1760 (2.4) | 6424 (4.3) | 0.103 | 1601 (2.7) | 1376 (2.3) | 0.024 |
| Arterial fibrillation (%) | 205 (0.3) | 632 (0.4) | 0.023 | 193 (0.3) | 116 (0.2) | 0.025 |
| Valvular heart disease (%) | 242 (0.3) | 522 (0.3) | 0.002 | 208 (0.3) | 163 (0.3) | 0.014 |
| Myocardial infarction (%) | 189 (0.3) | 723 (0.5) | 0.036 | 176 (0.3) | 152 (0.3) | 0.008 |
| History of cardiac surgery (%) | 140 (0.2) | 356 (0.2) | 0.01 | 130 (0.2) | 92 (0.2) | 0.015 |
| History of chronic Cerebrovascular disease (%) | 1706 (2.3) | 5005 (3.3) | 0.059 | 1553 (2.6) | 1169 (2.0) | 0.043 |
| Stroke (%) | 1227 (1.7) | 3988 (2.6) | 0.066 | 1119 (1.9) | 813 (1.4) | 0.041 |
| Peripheral vascular disease (%) | 2151 (3.0) | 6337 (4.2) | 0.068 | 1930 (3.2) | 1627 (2.7) | 0.03 |
| Renal dysfunction (%) | 752 (1.0) | 1396 (0.9) | 0.011 | 663 (1.1) | 491 (0.8) | 0.029 |
| Preoperative use of β‐blockers (%) | 1661 (2.3) | 6852 (4.6) | 0.125 | 1515 (2.5) | 1399 (2.3) | 0.013 |
| Preoperative use of aspirin (%) | 2080 (2.9) | 7015 (4.7) | 0.095 | 1810 (3.0) | 1636 (2.7) | 0.017 |
| Preoperative use of statin (%) | 1158 (1.6) | 4420 (2.9) | 0.091 | 1053 (1.8) | 1067 (1.8) | 0.002 |
| Preoperative Hb, g/L | 128.0 [117.0, 140.0] | 137.0 [125.0, 149.0] | 0.439 | 130.0 [119.0, 142.0] | 131.0 [119.0, 144.0] | 0.019 |
| Preoperative ALB, g/L | 41.1 [38.5, 43.6] | 41.6 [39.3, 43.9] | 0.161 | 41.2 [38.6, 43.7] | 41.3 [38.9, 43.6] | 0.011 |
| Preoperative TBIL, μmol/L | 10.4 [7.8, 14.4] | 10.8 [8.1, 14.4] | 0.048 | 10.6 [7.9, 14.5] | 10.4 [7.8, 14.2] | 0.016 |
| Preoperative PT, s | 13.2 [12.7, 13.8] | 13.0 [12.5, 13.5] | 0.213 | 13.2 [12.7, 13.7] | 13.0 [12.5, 13.6] | 0.129 |
| Preoperative NLR | 1.8 [1.3, 2.7] | 1.8 [1.4, 2.5] | 0.088 | 1.81 [1.34, 2.62] | 1.8 [1.4, 2.6] | 0.004 |
| Preoperative PLR | 122.8 [95.4, 163.7] | 114.2 [90.1, 147.3] | 0.192 | 121.1 [94.5, 160.1] | 119.1 [92.9, 156.3] | 0.037 |
| Surgery type (%) | ||||||
| Otolaryngology head and neck surgery | 7590 (10.4) | 14,248 (9.5) | 0.27 | 6369 (10.7) | 6855 (11.5) | 0.05 |
| Traumatology surgery | 2244 (3.1) | 4409 (2.9) | 1847 (3.1) | 1897 (3.2) | ||
| Gynecological and obstetric surgery | 6296 (8.6) | 9122 (6.1) | 4789 (8.0) | 5206 (8.7) | ||
| Abdominal surgery | 21,422 (29.4) | 36,219 (24.1) | 16,657 (27.9) | 16,030 (26.8) | ||
| Joint surgery | 3724 (5.1) | 12,189 (8.1) | 3186 (5.3) | 2979 (5.0) | ||
| Spinal surgery | 4154 (5.7) | 14,149 (9.4) | 3751 (6.3) | 3598 (6.0) | ||
| Oral surgery | 3744 (5.1) | 5733 (3.8) | 2885 (4.8) | 3146 (5.3) | ||
| Urology surgery | 4690 (6.4) | 13,930 (9.3) | 4082 (6.8) | 4121 (6.9) | ||
| General surgery | 5221 (7.2) | 11,787 (7.8) | 4516 (7.6) | 4456 (7.5) | ||
| Neurosurgical surgery | 6419 (8.8) | 13,929 (9.3) | 5580 (9.3) | 5378 (9.0) | ||
| Thoracic surgery | 4750 (6.5) | 10,535 (7.0) | 4090 (6.8) | 4149 (6.9) | ||
| Vascular surgery | 614 (0.8) | 1594 (1.1) | 519 (0.9) | 481 (0.8) | ||
| Other | 1983 (2.7) | 2720 (1.8) | 1475 (2.5) | 1449 (2.4) | ||
| Duration of surgery, min | 147.0 [100.0, 215.0] | 149.0 [102.0, 215.0] | 0.005 | 150.0 [105.0, 219.0] | 145.0 [95.0, 220.0] | 0.012 |
| Time of perioperative MAP > 60 min, min | 5.0 [0.0, 15.0] | 5.0 [0.0, 15.0] | 0.058 | 5.0 [0.0, 15.0] | 5.0 [0.0, 15.0] | 0.037 |
| Estimated blood loss, mL | 100.0 [50.0, 200.0] | 100.0 [50.0, 200.0] | 0.006 | 100.0 [50.0, 200.0] | 100.0 [50.0, 300.0] | 0.164 |
| Blood products depot | ||||||
| No | 63,666 (87.4) | 133,701 (88.8) | 0.043 | 52,981 (88.7) | 51,255 (85.8) | 0.087 |
| Yes | 9185 (12.6) | 16,863 (11.2) | 6765 (11.3) | 8490 (14.2) | ||
| Morphine equivalents, mg a | 120.0 [90.0, 150.0] | 123.0 [90.0, 150.0] | 0.138 | 120.0 [90.0, 150.0] | 120.0 [90.0, 150.0] | 0.085 |
| Inhalation anesthetics | ||||||
| No | 4696 (6.4) | 8939 (5.9) | 0.021 | 3941 (6.6) | 3469 (5.8) | 0.033 |
| Yes | 68,155 (93.6) | 141,625 (94.1) | 55,805 (93.4) | 56,276 (94.2) | ||
| Hormones | ||||||
| No | 13,917 (19.1) | 28,878 (19.2) | 0.002 | 11,598 (19.4) | 10,057 (16.8) | 0.067 |
| Yes | 58,934 (80.9) | 121,686 (80.8) | 48,148 (80.6) | 49,688 (83.2) | ||
| NSAIDs | ||||||
| No | 29,030 (39.8) | 54,584 (36.3) | 0.074 | 23,540 (39.4) | 29,059 (48.6) | 0.187 |
| Yes | 43,821 (60.2) | 95,980 (63.7) | 36,206 (60.6) | 30,686 (51.4) | ||
| Colloids infusion, mL/kg/min | 10.0 [7.4, 13.5] | 7.8 [5.8, 10.4] | 0.567 | 9.3 [7.0, 12.2] | 8.7 [6.2, 12.0] | 0.098 |
| Crystalloids infusion, mL/kg/min | 3.2 [0.0, 5.1] | 2.4 [0.0, 3.8] | 0.33 | 3.0 [0.0, 4.7] | 3.2 [1.1, 4.7] | 0.084 |
Note: The data are shown as the median (interquartile range), n (%), or mean ± SD.
Abbreviations: ALB, albumin; ASA, American Society of Anesthesiologists; BMI, body mass index; Hb, hemoglobin; MAP, mean arterial pressure; NLR, neutrophil‐to‐lymphocyte ratio; PLR, platelet‐to‐lymphocyte ratio; PSM, propensity score matching; PT, prothrombin time; SMD, standardized mean difference; TBIL, total bilirubin.
a
Including those intraoperatively and postoperatively (up to 7 days after surgery). Morphine 30 mg (per os) = morphine 10 mg (iv) = sufentanil 10 μg (iv) = fentanyl 100 μg (iv) = remifentanil 100 μg (iv) = 100 mg tramadol (iv) = tramadol 200 mg (per os) = oxycodone 15 mg (per os) = dezocine 10 mg (iv) = pethidine 100 mg (iv).