Table 1.
Risk factors analysis of patients with P. aeruginosa SSI and SSI due other organisms
| Epidemiological characteristics | Non-SSI (n = 3032) |
P. aeruginosa SSI (n = 62) | Other SSI (n = 607) |
*P-value | OR (95% CI) |
|---|---|---|---|---|---|
| Age, median (IQR), years | 69.6 (60.7–78) | 71.3 (64.9–80) | 69.9 (61.4–77) | 0.1 | 1.0 (0.97–1.12) |
| Male sex, n (%) | 1814 (59.8) | 44 (71) | 431 (71) | 0.9 | 1.0 (0.56–1.78) |
| ASA III-IV, n (%) | 1178 (38.9) | 42 (67.7) | 276 (45.5) | 0.001 | 2.5 (1.44–4.39) |
| NNIS 1–2, n (%) | 993 (32.8) | 46 (74.2) | 268 (44.2) | < 0.001 | 3.6 (2.01–6.56) |
| Indication for surgery, n (%): | |||||
| - Neoplasia | 2868 (94.6) | 57 (91.9) | 577 (95.1) | 0.3 | 0.5 (0.22–1.58) |
| - Inflammatory bowel disease | 73 (2.4) | 3 (4.8) | 15 (2.5) | 0.3 | 2.0 (0.56–7.13) |
| - Other | 87 (2.9) | 2 (3.2) | 14 (2.3) | 0.6 | 1.4 (0.31–6.36) |
| Type of surgery, n (%) | 0.2 | 1.3 (0.81–2.33) | |||
| - Colon | 2104 (69.4) | 34 (54.8) | 380 (62.6) | ||
| - Rectum | 928 (30.6) | 28 (45.2) | 227 (37.4) | ||
| Adequate antibiotic prophylaxis, n (%) | 2526 (83.3) | 55 (88.7) | 502 (82.7) | 0.2 | 1.6 (0.73–3.37) |
| Duration of surgery ≥75th pa, n (%) | 1163 (38.4) | 38 (61.3) | 251 (41.4) | 0.003 | 2.2 (1.31–3.83) |
| Laparoscopic surgery, n (%) | 1975 (65.1) | 25 (40.3) | 297 (48.9) | 0.2 | 0.7 (0.41–1.29) |
| Detection of SSI during hospitalization, n (%) | _ | 46 (74.2) | 435 (71.7) | 0.6 | 1.1 (0.65–1.93) |
| Oral antibiotic prophylaxis, n (%) | 1352 (44.6) | 11 (17.7) | 204 (33.6) | 0.01 | 0.4 (0.21–0.83) |
| Mechanical bowel preparation, n (%) | 2283 (77.1) | 50 (80.6) | 454 (75.8) | 0.4 | 1.3 (0.69–2.56) |
| Ostomy, n (%) | 715 (23.6) | 29 (46.8) | 218 (36) | 0.09 | 1.5 (0.92–2.64) |
| Previous chemotherapy, n (%) | 471 (15.5) | 15 (24.2) | 125 (20.6) | 0.5 | 1.2 (0.66–2.26) |
| Previous radiotherapy, n (%) | 452 (14.9) | 14 (22.6) | 112 (18.5) | 0.4 | 1.3 (0.68–2.41) |
| Type of SSI, n (%): | 0.6 | 1.1 (0.67–1.92) | |||
| - Incisional | _ | 29 (46.8) | 304 (50.1) | ||
| - Organ-space | _ | 33 (53.2) | 303 (49.9) | ||
P. aeruginosa: Pseudomonas aeruginosa, SSI: surgical site infection, IQR: interquartile range, ASA: American Society of Anaesthesiologists’ physical status, NNIS: National Nosocomial Infections Surveillance Risk Index
*P-value refers to comparison between P. aeruginosa SSI and other SSI
aLength of surgery greater than the 75th percentile of the procedure