Table 1.
Demographics of included patients
| Variables | Total | Non-SSI group | SSI group | p value |
|---|---|---|---|---|
| N (%) | 1046 (100%) | 972 (92.9%) | 74 (7.1%) | |
| Age, years, median (IQR) | 59.0 (52.0–70.0) | 62.0 (53.0–70.0) | 60.5 (50.0–71.0) | 0.841 |
| Gender (%) | 0.302 | |||
| Male | 619 (59.2%) | 571 (58.7%) | 48 (64.9%) | |
| Female | 427 (40.8%) | 401 (41.3%) | 26 (35.1%) | |
| BMI, median (IQR) | 23.0 (20.3–25.4) | 23.0 (20.3–25.2) | 23.9 (19.9–26.3) | 0.421 |
| Comorbidity (%) | ||||
| Diabetes mellitus | 128 (12.2%) | 115 (11.8%) | 13 (17.6%) | 0.147 |
| Hypertension | 257 (24.6%) | 229 (23.6%) | 28 (37.8%) | 0.006 |
| Chronic liver disease | 20 (1.9%) | 20 (2.1%) | 0 (0%) | 0.390 |
| Chronic kidney disease | 9(0.9%) | 9 (0.9%) | 0 (0%) | 1.00 |
| Chronic heart disease | 40 (3.8%) | 34 (3.5%) | 6 (8.1%) | 0.057 |
| Tuberculosis | 5 (0.5%) | 3 (0.3%) | 2 (2.7%) | 0.043 |
| Steroid use | 9 (0.9%) | 8 (0.8%) | 1 (1.4%) | 0.485 |
| Immunosuppressive medication | 11 (1.1%) | 9 (0.9%) | 2 (2.7%) | 0.180 |
| Smoking history (%) | 0.980 | |||
| No | 839 (80.2%) | 780 (80.2%) | 59 (79.7%) | |
| Former | 45 (4.3%) | 42 (4.3%) | 3 (4.1%) | |
| Current | 162 (15.5%) | 150 (15.4%) | 12 (16.2%) | |
| Hemoglobin, g/dl (%) | 0.183 | |||
| ≥ 11 | 762 (72.8%) | 713 (73.4%) | 49 (66.2%) | |
| < 11 | 284 (27.2%) | 259 (26.6%) | 25 (33.8%) | |
| Albumin, g/dl (%) | < 0.001 | |||
| ≥ 3.5 | 815 (77.9%) | 773 (79.5%) | 42 (56.8%) | |
| < 3.5 | 231 (22.1%) | 199 (20.5%) | 32 (43.2%) | |
| Blood glucose, mg/dl (%) | 0.025 | |||
| < 80 | 181 (17.3%) | 168 (17.3%) | 13 (17.6%) | |
| 80 ~ 150 | 771 (73.7%) | 723 (74.4%) | 48 (64.9%) | |
| > 150 | 94 (9.0%) | 81 (8.3%) | 13 (17.6%) | |
| LPS, day, median (IQR) | 6 (3.5–9.0) | 6 (3–9) | 7.5 (4–9) | 0.130 |
IQR interquartile range, BMI body mass index, LPS Length of preoperative stay