Table 3a.

Multivariable linear regression: effect of farm-level factors on relative transmission risk computed for frequency-dependent within-flock transmission, ${\overline{TR}}_i^{FD}$ (n = 98^f farms).

Predictor variablesa	Linear model coefficientb	95% confidence intervals	p-Value
Interceptc	2.114	1.989 to 2.239	<0.0001
Mean daily vehicle loads	0.002	0.0016 to 0.0026	<0.0001
Time between consecutive visit days	−0.033	−0.054 to −0.013	0.002
Network connectivityd	0.0004	−5.26 × 10−5 to 0.001	0.077
Wales vs. Northe	−0.203	−0.564 to 0.157	0.266
West vs. Northe	0.096	−0.214 to 0.405	0.541