Table 2. Univariate analysis for risk factors associated with SSI and binary logistic regression for the significant factors.
*significant difference; OR: Odds Ratio (CI: Confidence Interval); DM - diabetes mellitus; ASA - American Society of Anesthesiologists; SSI - surgical site infection
| Risk factors | Studied patients (No=433) | Test of significance | P-value | |
| With SSI | Without SSI | OR (95% CI) | ||
| (No=31) | (No=402) | |||
| Age (year) | 24.42±18.14 | 25.10±14.26 | Mann Whitney U test=1.20 | 0.23 |
| Gender | ||||
| Male | 17 (54.8%) | 236 (58.7%) | χ2test=0.18 | 0.67 |
| Female | 14 (45.2%) | 166 (41.3%) | ||
| Hypertension | ||||
| No | 29 (93.5%) | 379 (94.3%) | Fisher's exact test=0.03 | 0.87 |
| Yes | 2 (6.5%) | 23 (5.7%) | ||
| DM | ||||
| No | 29 (93.5%) | 380 (94.5%) | Fisher's exact test=0.05 | 0.82 |
| Yes | 2 (6.5%) | 22 (5.5%) | ||
| Both hypertension and DM | ||||
| No | 31 (100%) | 388 (96.5%) | Fisher's exact test=1.12 | 0.29 |
| Yes | 0 (0.0%) | 14 (3.5%) | ||
| Blood types | ||||
| A+ | 18 (58.1%) | 132 (32.8%) | ||
| AB | 3 (9.7%) | 20 (5.0%) | ||
| B+ | 4 (12.9%) | 57 (14.2%) | χ2test =12.22 | 0.06 |
| B- | 0 (0.0%) | 3 (0.7%) | ||
| A- | 0 (0.0%) | 9 (2.2%) | ||
| O+ | 6 (19.4%) | 159 (39.6%) | ||
| O- | 0 (0.0%) | 22 (5.5%) | ||
| Perioperative factors | ||||
| ASA classification | ||||
| ≤2 | 21 (67.7%) | 303 (75.4%) | χ2test =0.89 | 0.35 |
| >2 | 10 (32.3%) | 99 (24.6%) | ||
| Prophylactic antibiotics | ||||
| No | 18 (58.1%) | 279 (69.4%) | χ2test =1.72 | 0.19 |
| Yes | 13 (41.9%) | 123 (30.6%) | ||
| Preoperative shaving | ||||
| No | 26 (83.9%) | 297 (73.9%) | χ2test =1.52 | 0.22 |
| Yes | 5 (16.1%) | 105 (26.1%) | ||
| Antiseptic used for skin preparation | ||||
| Providone Iodine | 10 (32.3%) | 166 (41.3%) | χ2test =0.97 | 0.32 |
| Chlorhexidine | 21 (67.7%) | 236 (58.7%) | ||
| Type of surgery | 0.0001* | |||
| Open | 24 (77.4%) | 166 (41.3%) | χ2test =15.25 | 4.11 (1.68-10.06) |
| Laparoscopic | 7 (22.6%) | 236 (58.7%) | ||
| Duration of the procedure (min.) | 9.71±9.29 | 3.06±4.13 | Mann Whitney U test=6.44 | 0.0001* |
| 1.17 (1.08-1.27) | ||||
| Urgency of the operation | ||||
| Urgent | 31 (100%) | 392 (97.5%) | Fisher's exact test=0.79 | 0.37 |
| Elective | 0 (0.0%) | 10 (2.5%) | ||
| Converting to open appendectomy | ||||
| No | 30 (96.8%) | 392 (97.5%) | ||
| Yes | 1 (3.2%) | 10 (2.5%) | Fisher's exact test=0.06 | 0.8 |
| Wound infection category | ||||
| Clean-contaminated | 31 (100%) | 400 (99.5%) | Fisher's exact test =0.15 | 0.69 |
| Contaminated | 0 (0.0%) | 2 (0.5%) | ||
| Histopathology of the appendix | ||||
| No pathology | ||||
| Yes | 0 (0.0%) | 32 (8.0%) | Fisher's exacttest =2.66 | 0.15 |
| No | 31 (100%) | 370 (92.0%) | ||
| Simple appendicitis | ||||
| Yes | 4 (12.9%) | 70 (17.4%) | χ2test =0.41 | 0.52 |
| No | 27 (87.1%) | 332 (82.6%) | ||
| Complicated appendicitis | ||||
| Yes | 27 (87.1%) | 295 (73.4%) | χ2test =2.84 | 0.09 |
| No | 4 (12.9%) | 107 (26.6%) | ||
| Gangrenous | ||||
| Yes | 2 (6.5%) | 24 (6.0%) | Fisher' exact test =0.01 | 1 |
| No | 29 (93.5%) | 378 (94.0%) | ||
| Perforated | 0.002* | |||
| Yes | 9 (29.0%) | 36 (9.0%) | Fisher' exacttest =12.46 | 4.16 (1.78-9.71) |
| No | 22 (71.0%) | 366 (91.0%) | ||
| Suppurative | ||||
| Yes | 16 (51.6%) | 231 (57.5%) | χ2test =0.40 | 0.53 |
| No | 15 (48.4%) | 171 (42.5%) | ||
| Other findings | ||||
| Neoplasm | 0 (0.0%) | 4 (1.0%) | χ2test =0.39 | 0.82 |
| Schistosomiasis | 0 (0.0%) | 1 (0.2%) | ||