Table 4.

Fixed-effects multivariable logistic regression model including covariates associated with the probability of isolating Campylobacter fetus spp. from sheep faeces on Lancashire sheep farms. Farm is considered as a fixed effect (n = 4). Coefficients for time covariates are not included in Table 4

Covariate	Estimate β	95% CI	OR	95% CI	Wald test P value
Farm
Farm 9 vs. zone 15	1·50	0·74 to 2·26	4·5	2·1–9·6	<0·0001
Farm 12 vs. zone 15	1·06	0·26 to 1·85	2·87	1·30–6·34	<0·0001
Other bacteria isolated from same faecal pat	−0·76	−1·32 to −0·20	0·47	0·27–0·81	0·007
Baseline: farm 15 and no other bacteria isolated	−2·91	−3·64 to −2·19

OR, Odds ratio; CI, confidence interval.