Table 1 Baseline characteristics of unadjusted sample and propensity score-matched sample
Characteristic | Unadjusted sample (n = 221,542) | PSM adjusted (2:1) (n = 120,158) | ||||
|---|---|---|---|---|---|---|
PNI ≥ 38.8 (n = 172,487) | PNI < 38.8 (n = 49,055) | SMD | PNI ≥ 38.8 (n = 80,106) | PNI < 38.8 (n = 40,052) | SMD | |
Age, years | 49 (14.2) | 57 (13.9) | 0.511 | 55 (13.3) | 55 (13.6) | 0.009 |
Sex (male) (%) | 86,940 (50.4) | 25,375 (51.7) | 0.026 | 40,809 (50.9) | 19,687 (49.2) | 0.036 |
BMI, kg·m2 | 24.55 (3.66) | 23.74 (3.68) | 0.221 | 24.07 (3.41) | 24.07 (3.71) | 0.001 |
ASA classification (%) | Â | Â | 0.366 | Â | Â | 0.137 |
 Class I | 28,342 (16.4) | 4145 (8.4) |  | 9523 (11.9) | 4026 (10.1) |  |
 Class II | 133,422 (77.4) | 37,340 (76.1) |  | 63,467 (79.2) | 30,848 (77.0) |  |
 Class III | 10,723 (6.2) | 7570 (15.4) |  | 7116 (8.9) | 5178 (12.9) |  |
 Hypertension (%) | 33,189 (19.2) | 10,453 (21.3) | 0.051 | 18,347 (22.9) | 7859 (19.6) | 0.08 |
 Diabetes mellitus (%) | 20,111 (11.7) | 7253 (14.8) | 0.092 | 11,097 (13.9) | 5454 (13.6) | 0.007 |
 Coronary heart disease (%) | 5613 (3.3) | 2395 (4.9) | 0.082 | 3510 (4.4) | 1685 (4.2) | 0.009 |
 Arterial fibrillation (%) | 497 (0.3) | 297 (0.6) | 0.048 | 332 (0.4) | 179 (0.4) | 0.005 |
 Arrhythmology (%) | 25,622 (14.9) | 8402 (17.1) | 0.062 | 11,517 (14.4) | 6424 (16.0) | 0.046 |
 Previous ischemic stroke (%) | 3536 (2.1) | 1521 (3.1) | 0.066 | 2072 (2.6) | 1018 (2.5) | 0.003 |
 Transient ischemic attack (%) | 3933 (2.3) | 1853 (3.8) | 0.087 | 2289 (2.9) | 1293 (3.2) | 0.022 |
 Chronic obstructive pulmonary disease (%) | 1208 (0.7) | 528 (1.1) | 0.04 | 680 (0.8) | 344 (0.9) | 0.001 |
 Peripheral vascular disease (%) | 5586 (3.2) | 2605 (5.3) | 0.103 | 2867 (3.6) | 2053 (5.1) | 0.076 |
 Renal dysfunction (%) | 1227 (0.7) | 813 (1.7) | 0.088 | 716 (0.9) | 626 (1.6) | 0.061 |
 Preoperative MAP, mmHg | 91.9 (11.5) | 91.1 (11.7) | 0.066 | 92.8 (11.4) | 91.1 (11.7) | 0.153 |
 Preoperative β blockers (%) | 5903 (3.4) | 2265 (4.6) | 0.061 | 3215 (4.0) | 1690 (4.2) | 0.01 |
 Preoperative ACEI (%) | 3388 (2.0) | 1043 (2.1) | 0.011 | 1750 (2.2) | 803 (2.0) | 0.013 |
 Preoperative ARB (%) | 6824 (4.0) | 1905 (3.9) | 0.004 | 3582 (4.5) | 1491 (3.7) | 0.038 |
 Preoperative aspirin (%) | 4639 (2.7) | 1683 (3.4) | 0.043 | 2791 (3.5) | 1276 (3.2) | 0.017 |
 Preoperative glucocorticoid (%) | 10,737 (6.2) | 4944 (10.1) | 0.141 | 6187 (7.7) | 3204 (8.0) | 0.01 |
 Preoperative Hemoglobin, g/L | 137 (17.1) | 122 (18.6) | 0.823 | 135 (17.1) | 123(18.2) | 0.669 |
 Preoperative LLR | 3.48 (2.26) | 4.67 (4.37) | 0.343 | 3.93 (2.95) | 4.08 (2.74) | 0.051 |
Preoperative LLR | ||||||
 < 3.28 | 106,753 (61.9) | 20,760 (42.3) | 0.399 | 39,339 (49.1) | 19,621 (49.0) | 0.002 |
 ≥ 3.28 | 65,734 (38.1) | 28,295 (57.7) |  | 40,767 (50.9) | 20,431 (51.0) |  |
 Emergency (%) | 3527 (2.0) | 1943 (4.0) | 0.112 | 2120 (2.6) | 1309 (3.3) | 0.037 |
Surgical procedures (%) | Â | Â | 0.43 | Â | Â | 0.023 |
 Stomatological and ENT | 27,047 (15.7) | 4202 (8.6) |  | 8005 (10.0) | 4023 (10.0) |  |
 Trauma surgery | 4420 (2.6) | 2096 (4.3) |  | 2750 (3.4) | 1474 (3.7) |  |
 Gynaecology | 12,413 (7.2) | 2935 (6.0) |  | 5411 (6.8) | 2777 (6.9) |  |
 Intra-abdominal surgery | 51,148 (29.7) | 22,750 (46.4) |  | 32,445 (40.5) | 15,894 (39.7) |  |
 Joint arthroplasty | 11,749 (6.8) | 4126 (8.4) |  | 7098 (8.9) | 3605 (9.0) |  |
 Spine | 14,961 (8.7) | 3232 (6.6) |  | 6034 (7.5) | 3034 (7.6) |  |
 Urinary surgery | 15,461 (9.0) | 3076 (6.3) |  | 5806 (7.2) | 2908 (7.3) |  |
 Neurosurgery | 17,170 (10.0) | 2707 (5.5) |  | 5314 (6.6) | 2622 (6.5) |  |
 Thoracic or vascular | 14,287 (8.3) | 3077 (6.3) |  | 5683 (7.1) | 2950 (7.4) |  |
 Other (plastic surgery, etc.) | 3831 (2.2) | 854 (1.7) |  | 1560 (1.9) | 765 (1.9) |  |
 Malignant tumor surgery (%) | 74,358 (43.1) | 26,216 (53.4) | 0.208 | 40,895 (51.1) | 19,956 (49.8) | 0.025 |
 Duration of procedures, min | 167.5 (96.1) | 188.4 (102.1) | 0.211 | 180.5 (101.2) | 180.4 (98.2) | 0.001 |
 Estimated blood loss, mL | 203.2 (403.4) | 302.8 (565.5) | 0.203 | 256.3 (485.7) | 279.0 (523.2) | 0.045 |
Bleeding volume | ||||||
 ≤ 50 | 71,316 (41.3) | 13,925 (28.4) | 0.303 | 25,274 (31.6) | 12,565 (31.4) | 0.008 |
  (50,200] | 64,971 (37.7) | 19,842 (40.4) |  | 32,417 (40.5) | 16,133 (40.3) |  |
 > 200 | 36,200 (21.0) | 15,288 (31.2) |  | 22,415 (28.0) | 11,354 (28.3) |  |
 Crystalloids infusion, ml/kg/min | 1511.5 (740.6) | 1756.4 (820.2) | 0.313 | 1656.0 (795.2) | 1661.9 (775.0) | 0.007 |
 Colloids infusion, ml/kg/min | 492.7 (487.6) | 652.7 (550.0) | 0.308 | 578.3 (519.5) | 622.7 (543.3) | 0.084 |
 Intraoperative NSAIDs (%) | 46,315 (26.9) | 14,785 (30.1) | 0.073 | 23,170 (28.9) | 11,574 (28.9) | 0.001 |
 Intraoperative glucocorticoid (%) | 139,015 (80.6) | 40,034 (81.6) | 0.026 | 65,235 (81.4) | 32,598 (81.4) | 0.001 |
 ICU admission after surgery (%) | 17,906 (10.4) | 8296 (16.9) | 0.191 | 9886 (12.3) | 4657 (11.6) | 0.022 |