Demographic, operative and postoperative risk factor variables of patients with and without surgical site infection
| Variable | Group; no. (%) of patients* | p value | |
|---|---|---|---|
| No SSI | SSI | ||
| Operation | < 0.001† | ||
| Laparoscopic cholecystectomy | 106 (37.6) | 5 (9) | |
| Hernia repair | 61 (21.6) | 6 (11) | |
| Gastric sleeve/bypass | 56 (19.8) | 0 (0) | |
| Appendectomy | 14 (5.0) | 4 (7) | |
| Laparotomy | 11 (3.9) | 24 (44) | |
| Colectomy/abdominoperineal resection/low anterior resection | 6 (2.1) | 5 (9) | |
| Hepatectomy/Whipple procedure | 4 (1.4) | 8 (14) | |
| Other | 24 (8.5) | 3 (5) | |
| Wound class | < 0.001† | ||
| Clean | 53 (18.8) | 3 (5) | |
| Clean-contaminated | 219 (77.6) | 38 (69) | |
| Contaminated/dirty | 10 (3.5) | 14 (25) | |
| Urgency | < 0.001† | ||
| Emergent | 50 (17.7) | 30 (54) | |
| Elective | 232 (82.3) | 25 (45) | |
| Approach | < 0.001† | ||
| Laparoscopic | 192 (68.1) | 7 (13) | |
| Laparoscopic converted to open | 3 (1.1) | 3 (5) | |
| Open midline | 35 (12.4) | 35 (64) | |
| Open nonmidline | 52 (18.4) | 10 (18) | |
| Length of operation, min, median (IQR) | 83 (110–155) | 184 (113–292) | < 0.001† |
| Drains | 78 (27.6) | 27 (49) | 0.007‡ |
| Blood transfusion | 14 (5.0) | 22 (40) | < 0.001† |
| Postoperative stay, d, median (IQR) | 2 (1–3) | 13 (6–25) | < 0.001† |
| Intensive care unit admission | 22 (7.8) | 28 (51) | < 0.001‡ |
| Death within 30 d | 2 (0.7) | 2 (4) | 0.07 |