Table 7.

Linear regression model of variables associated with the concentration of E. coli (natural log cfu/g) in samples collected from the floor(s) of commercial broiler chicken barns in Ontario that were disinfected during the rest period (n = 336 samples from 17 b; random effects for barn, visit, and floor; α = 0.05).

Variable	Coefficient	95% CI	P value
Sampling point1
Baseline (n = 112)	Referent
2 d After sanitation (n = 112)	-4.74	−5.62–−3.86	<0.001
6 d After sanitation (n = 112)	-5.29	−6.17–−4.41	<0.001
Flooring type1
Concrete (n = 204)	Referent
Wood (n = 132)	0.69	0.02–1.36	0.043

Variance components	Variance	SE	ICC
Barn	1.65	0.78	0.27
Visit	0.51	0.42	0.35
Floor	1.21	0.43	0.55
Sample	2.78	0.25

Overall P value for the model: < 0.0001.

Abbreviations: CI, confidence interval; ICC, intraclass correlation coefficient; SE, significance of error.

¹Included regardless of significance because it was an a priori variable of interest.