Introduction
Patients and methods
Study design
Data collection
Statistical analysis
Results
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 |
Variables | Total (n = 1046) | Non-SSI group (n = 972) | SSI group (n = 74) | p value |
---|---|---|---|---|
Type of surgery (%) | 0.002 | |||
Colon surgery | 641 (61.3%) | 583 (60.0%) | 58 (78.4%) | |
Rectal surgery | 405 (38.7%) | 389 (40.0%) | 16 (21.6%) | |
Urgency of surgery (%) | < 0.001 | |||
Elective | 978 (93.5%) | 922 (94.9%) | 56 (75.7%) | |
Emergency | 68 (6.5%) | 50 (5.1%) | 18 (24.3%) | |
ASA score (%) | 0.001 | |||
1 or 2 | 818 (78.2%) | 772 (79.4%) | 46 (62.2%) | |
3 or 4 | 228 (21.8%) | 200 (20.6%) | 28 (37.8%) | |
Surgical wound class (%) | < 0.001 | |||
Clean-contaminated | 992 (94.9%) | 932 (95.9%) | 60 (81.1%) | |
Contaminated or dirty | 54 (5.2%) | 40 (4.1%) | 14 (18.9%) | |
Timing of hair removal (%) | 0.028 | |||
None | 188 (18.0%) | 167 (17.2%) | 21 (28.4%) | |
Night before surgery | 672 (64.2%) | 634 (65.2%) | 38 (51.4%) | |
Day of surgery | 186 (17.8%) | 171 (17.6%) | 15 (20.3%) | |
Hair removal | 0.016 | |||
No | 188 (18.0%) | 167 (17.2%) | 21 (28.4%) | |
Yes | 858 (82.0%) | 805 (82.8%) | 53 (71.6%) | |
Bowel preparation (%) | < 0.001 | |||
None | 331 (31.6%) | 294 (30.2%) | 37 (50.0%) | |
MBP only | 575 (55.0%) | 549 (56.5%) | 26 (35.1%) | |
OABP only | 42 (4.0%) | 36 (3.7%) | 6 (8.1%) | |
MBP + OABP | 98 (9.4%) | 93 (9.6%) | 5 (6.8%) | |
Hand preparation (%) | 0.209 | |||
Disinfectant | 831 (79.4%) | 768 (79.0%) | 63 (85.1%) | |
Scrubbing | 215 (20.6%) | 204 (21.0%) | 11 (14.9%) | |
Approach (%) | < 0.001 | |||
Open | 391 (37.4%) | 341 (35.1%) | 50 (67.6%) | |
Laparoscopic or robotic | 655 (62.6%) | 631 (64.9%) | 24 (32.4%) | |
Incisional protection (%) | 0.151 | |||
None | 211 (20.2%) | 191 (19.7%) | 20 (27.0%) | |
Gauze | 121 (11.6%) | 113 (11.6%) | 8 (10.8%) | |
Adhesive incise drapes | 340 (32.5%) | 324 (33.3%) | 16 (21.6%) | |
Wound edge protector | 374 (35.8%) | 344 (35.4%) | 30 (40.5%) | |
Skin closure materials (%) | 0.027 | |||
Silk sutures | 627 (60.0%) | 579(59.6%) | 48(64.9%) | |
Absorbable sutures | 264 (25.2%) | 253(26.0%) | 11(14.9%) | |
Skin staples | 120 (11.5%) | 111(11.4%) | 9(12.2%) | |
other | 35 (3.3%) | 29(3.0%) | 6(8.1%) | |
Fascial or muscle suture materials (%) | 0.545 | |||
Silk sutures | 153 (14.6%) | 140 (14.4%) | 13 (17.6%) | |
Absorbable sutures | 408 (39.0%) | 377 (38.8%) | 31 (41.9%) | |
antimicrobial-coated and absorbable sutures | 485 (46.4%) | 455 (46.8%) | 30 (40.5%) | |
Incisional wound irrigation (%) | 0.037 | |||
None | 81 (7.7%) | 72 (7.4%) | 9 (12.2%) | |
Povidone-iodine solution | 182 (17.4%) | 172 (17.7%) | 10 (13.5%) | |
Hydrogen peroxide solution | 51 (4.9%) | 48 (4.9%) | 3 (4.1%) | |
Saline | 701 (67.0%) | 655 (67.4%) | 46 (62.2%) | |
Other | 31 (3.0%) | 25 (2.6%) | 6 (8.1%) | |
Colostomy/ileostomy | < 0.001 | |||
No | 920 (88.0%) | 869 (89.4%) | 51 (68.9%) | |
Yes | 126 (12.0%) | 103 (10.6%) | 23 (31.1%) | |
Grade of lead surgeon (%) | 0.068 | |||
Senior | 694 (66.3%) | 651 (67.0%) | 43 (58.1%) | |
Middle | 304 (29.1%) | 280 (28.8%) | 24 (32.4%) | |
Junior | 48 (4.6%) | 41 (4.2%) | 7 (9.5%) | |
Surgical duration, min, median (IQR) | 180.0 (130.0–225.0) | 180.0 (130.0–220.0) | 193.5 (143.8–254.3) | 0.019 |
NNIS risk index | < 0.001 | |||
0 or 1 | 969 (92.6%) | 916 (94.2%) | 53 (71.6%) | |
2 or 3 | 77 (7.4%) | 56 (5.8%) | 21 (28.4%) |
Variables | Total (n = 1046) | Non-SSI group (n = 972) | SSI group (n = 74) | p value |
---|---|---|---|---|
Length of hospital stay, day, median (IQR) | 16.0 (12.0–21.0) | 15.0 (12.0–21.0) | 22.5 (17.0–33.0) | < 0.001 |
Length of postoperative stay, day, median (IQR) | 9.0 (7.0–12.0) | 9.0 (7.0–12.0) | 15.0 (11.0–24.0) | < 0.001 |
30-day mortality, n, (%) | 6(0.6%) | 3 (0.3%) | 3 (4.1%) | 0.006 |
Medical cost, yuan, median (IQR) | 58,982 (42972–79,262) | 57,827 (42000–77,919) | 74,620 (59078–107,612) | < 0.001 |
Surgery to SSI time, day, median (IQR) | – | – | 5.5 (3.0–9.0) | – |
SSI type, n, (%) | – | – | – | |
Superficial incisional infection | – | – | 32 (43.2%) | – |
Deep incisional infection | – | – | 18 (24.3%) | – |
Organ-space infection | – | – | 24 (32.4%) | – |
Pathogen, n, (%) | ||||
Escherichia coli | – | – | 25(33.8%) | – |
Klebsiella pneumoniae | – | – | 4(5.4%) | – |
Enterococcus faecalis | – | – | 3(4.1%) | – |
Enterococcus faecium | – | – | 2(2.7%) | – |
Morganella morganii | – | – | 2(2.7%) | – |
Candida albicans | – | – | 2(2.7%) | – |
Pseudomonas aeruginosa | – | – | 1(1.4%) | – |
Acinetobacter baumanii | – | – | 1(1.4%) | – |
Staphylococcus aureus | – | – | 1(1.4%) | – |
Proteus mirabilis | – | – | 1(1.4%) | – |
Enterobacter cloacae | – | – | 1(1.4%) | – |
Staphylococcus epidermidis | – | – | 1(1.4%) | – |
Negative | – | – | 21(28.4%) | – |
None of germiculture | – | – | 17(23.0%) | – |
Variables | univariate | multivariate | ||
---|---|---|---|---|
p value | OR (95% CI) | p value | OR (95% CI) | |
Hypertension | ||||
Yes | 0.007 | 1.975(1.207–3.232) | 0.024 | 1.903(1.088–3.327) |
Noa | ||||
Tuberculosis | ||||
Yes | 0.017 | 8.972(1.475–54.559) | 0.083 | 7.880(0.762–81.492) |
Noa | ||||
Albumin | ||||
≥ 3.5 g/dla | ||||
< 3.5 g/dl | < 0.001 | 2.960(1.821–4.810) | 0.069 | 1.715(0.958–3.068) |
Blood glucose | ||||
80–150 mg/dla | ||||
> 150 mg/dl | 0.008 | 2.417(1.256–4.651) | 0.879 | 1.065(0.475–2.388) |
< 80 mg/dl | 0.637 | 1.166(0.617–2.200) | ||
Type of surgery | ||||
Rectal surgerya | ||||
Colon surgery | 0.002 | 2.419(1.370–4.269) | 0.154 | 0.631(0.335–1.188) |
Urgency of surgery | ||||
Electivea | ||||
Emergency | < 0.001 | 5.927(3.245–10.827) | 0.913 | 1.056(0.397–2.815) |
Timing of hair removal | ||||
Nonea | ||||
Night before surgery | 0.009 | 0.477(0.272–0.834) | 0.342 | 0.711(0.352–1.442) |
Day of surgery | 0.311 | 0.698(0.348–1.399) | ||
Bowel preparation | ||||
Nonea | ||||
MBP only | < 0.001 | 0.376(0.223–0.634) | 0.185 | 0.650(0.344–1.229) |
OABP only | 0.554 | 1.324(0.523–3.355) | ||
MBP + OABP | 0.083 | 0.427(0.163–1.119) | ||
Approach | ||||
Opena | ||||
Laparoscopic or robotic | < 0.001 | 0.259(0.157–0.429) | < 0.001 | 0.363(0.200–0.659) |
Incisional protection | ||||
Nonea | ||||
Wound edge protector | 0.545 | 0.833(0.460–1.507) | ||
Gauze | 0.368 | 0.676(0.288–1.585) | ||
Adhesive incise drapes | 0.031 | 0.472(0.239–0.932) | 0.018 | 0.400(0.187–0.855) |
Skin closure materials | ||||
Silk suturesa | ||||
Absorbable sutures | 0.060 | 0.524(0.268–1.027) | ||
Skin staples | 0.953 | 0.978(0.466–2.051) | ||
other | 0.053 | 2.496(0.988–6.307) | ||
Incisional wound irrigation | ||||
Nonea | ||||
Incisional wound irrigation | 0.111 | 0.465(0.181–1.193) | ||
Hydrogen peroxide solution | 0.317 | 0.500(0.129–1.942) | ||
Saline | 0.134 | 0.562(0.264–1.195) | ||
Other | 0.257 | 1.920(0.621–5.936) | ||
Colostomy/ileostomy | ||||
Noa | ||||
Yes | < 0.001 | 3.805(2.233–6.483) | 0.081 | 1.820(0.929–3.564) |
NNIS risk index | ||||
0 or 1a | ||||
2 or 3 | < 0.001 | 6.481(3.655–11.493) | < 0.001 | 3.840(1.926–7.658) |