Table 3.
Relative risks, with 95% confidence intervals, of SSI for periods with cephalothin and metronidazole relative to periods with doxycycline and metronidazole
| Patient group | Periods | Crude RRa |
95% CI | Adjusted RRb |
95% CI |
|---|---|---|---|---|---|
| Colorectal patientsc | 2 versus 1 and 3 | 1.60 | 1.23, 2.09 | 1.61 | 1.22, 2.12 |
| 2 versus 1 | 1.56 | 1.18, 2.06 | 1.57 | 1.18, 2.19 | |
| 2 versus 3 | 1.74 | 1.17, 2.60 | 1.74 | 1.15, 2.62 | |
| Gyneacology patientsd | 2 and 3 versus 1 | 1.10 | 0.75, 1.62 | 0.98 | 0.64, 1.49 |
a Calculated by using log-binomial regression models.
b Adjusted for age, gender, surgical procedure, ASA score, emergency procedure, time of operation and operation time.
c Period 1 was the first period of treatment with doxycycline and metronidazole. Period 2 was the period when cephalothin and metronidazole was used, and period 3 was the period when we returned to doxycycline and metronidazole.
d Period 1 was the first period of treatment with doxycycline and metronidazole. Cephalothin and metronidazole was used throughout period 2 and 3 (i.e., did not return to doxycycline and metronidazole in period 3).