Table 3 Perioperative characteristics of included patients.
Variables | SSI group (n = 71) | Non-SSI group (n = 882) | Statistic | P value |
|---|---|---|---|---|
Type of surgery (%) | χ2 = 61.515 | < 0.001 | ||
Gastric surgery | 2 (2.8) | 53 (6.0) | ||
Hepatobiliary surgery | 4 (5.6) | 56 (6.4) | ||
Small bowel surgery | 17 (23.9) | 100 (11.4) | ||
Appendix surgery | 22 (31.0) | 573 (65.1) | ||
Colon surgery | 20 (28.2) | 39 (4.4) | ||
Rectal surgery | 2 (2.8) | 3 (0.3) | ||
Others | 5 (7.0) | 69 (7.8) | ||
Colorectal surgery (%) | χ2 = 72.133 | < 0.001 | ||
Yes | 22 (31.0) | 42 (4.8) | ||
No | 49 (69.0) | 840 (95.5) | ||
Bowel preparation (%) | 0.528 | |||
None | 62 (87.3) | 778 (88.4) | ||
MBP only | 4 (5.6) | 27 (3.1) | ||
OABP only | 5 (7.0) | 75 (8.5) | ||
MBP + OABP | 0 | 2 (0.2) | ||
Intestinal obstruction (%) | χ2 = 29.526 | < 0.001 | ||
Yes | 20 (28.2) | 73 (8.3) | ||
No | 51 (71.8) | 809 (91.9) | ||
Gastrointestinal perforation (%) | χ2 = 0.031 | 0.861 | ||
Yes | 6 (8.5) | 80 (9.1) | ||
No | 65 (91.5) | 802 (91.1) | ||
ASA score (%) | χ2 = 31.630 | < 0.001 | ||
1 | 15 (21.1) | 340 (38.6) | ||
2 | 28 (39.4) | 406 (46.1) | ||
3 | 20 (28.2) | 112 (12.7) | ||
4 | 8 (11.3) | 24 (2.7) | ||
NNIS risk index | χ2 = 91.767 | < 0.001 | ||
0 | 17 (23.9) | 551 (62.6) | ||
1 | 27 (38.0) | 252 (28.6) | ||
2 | 19 (26.8) | 73 (8.3) | ||
3 | 8 (11.3) | 6 (0.7) | ||
Approach | χ2 = 53.600 | < 0.001 | ||
Open | 61 (85.9) | 362 (41.1) | ||
Laparoscopic | 10 (14.1) | 520 (59.1) | ||
Surgical wound class (%) | χ2 = 0.766 | 0.381 | ||
Clean-contaminated | 48 (67.6) | 639 (72.6) | ||
Contaminated or dirty | 23 (32.4) | 243 (27.6) | ||
Incisional protection (%) | χ2 = 23.051 | < 0.001 | ||
None | 29 (40.8) | 537 (61.0) | ||
Gauze | 14 (19.7) | 135 (15.3) | ||
Adhesive drapes | 12 (16.9) | 145 (16.5) | ||
Wound edge protector | 16 (22.5) | 65 (7.4) | ||
Wound irrigation (%) | χ2 = 23.442 | < 0.001 | ||
No | 12 (16.9) | 406 (46.1) | ||
Saline | 35 (49.3) | 306 (34.8) | ||
Povidone iodine solution | 24 (33.8) | 170 (19.3) | ||
Grade of lead surgeon (%) | χ2 = 12.356 | 0.002 | ||
Junior | 0 | 71 (8.1) | ||
Middle | 22 (31.0) | 371 (42.2) | ||
Senior | 49 (69.0) | 440 (50.0) | ||
Surgical duration, min, median (IQR) | 130.0 (83.0–205.0) | 75.0 (53.0–114.3) | U = 45,556.5 | < 0.001 |
