Predictor variable | N | Infection | Rate* | Relative risk | |||
---|---|---|---|---|---|---|---|
Crude | 95% CI | Adjusted** | 95% CI | ||||
Duration of antibiotic prophylaxis | |||||||
None | 167 | 5 | 3.0 | 1.00 | Reference | 1.00 | Reference |
1 day | 1159 | 12 | 1.0 | 0.34 | 0.12–0.97 | 0.30 | 0.10–0.88 |
>1 day | 813 | 9 | 1.1 | 0.36 | 0.12–1.09 | 0.32 | 0.10–0.98 |
Time of first antibiotic dose administration | |||||||
None | 167 | 5 | 3.0 | 1.00 | Reference | 1.00 | Reference |
>1 hour preoperatively | 1004 | 8 | 0.8 | 0.26 | 0.08–0.81 | 0.22 | 0.07–0.70 |
≤ 1 hour preoperatively or interoperation | 814 | 9 | 1.1 | 0.36 | 0.12–1.09 | 0.33 | 0.11–1.02 |
Postoperatively | 154 | 4 | 2.6 | 0.86 | 0.23–3.28 | 0.78 | 0.20–3.00 |
Antibiotic agent | |||||||
None | 167 | 5 | 3.0 | 1.00 | Reference | 1.00 | Reference |
Single dose combination metronidazole and gentamicin | 766 | 8 | 1.0 | 0.34 | 0.11–1.06 | 0.28 | 0.09–0.90 |
Combination metronidazole and gentamicin within 1 day | 130 | 1 | 0.8 | 0.25 | 0.03–2.18 | 0.22 | 0.03–1.98 |
Combination metronidazole and gentamicin > 1 day | 370 | 4 | 1.1 | 0.35 | 0.09–1.34 | 0.29 | 0.08–1.12 |
Others*** | 706 | 8 | 1.1 | 0.37 | 0.12–1.15 | 0.37 | 0.12–1.15 |