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

RR^a

95% CI

Adjusted

RR^b

95% CI

Colorectal patients^c

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 patients^d

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).

Baatrup et al. BMC Surgery 2009 9:17   doi:10.1186/1471-2482-9-17