Table 3.

The final generalised linear mixed model presenting risk factors of bovine coronavirus seropositivity in cattle (number of observations = 229)

Variable	Category	Odds ratio	β (SE)	z	P > |z|	95% CI
Age group*
	≤3 months	reference
	3–6 months	0.58	0.32	−0.99	0.323	0.19–1.72
	≥6 months	0.27	0.14	−2.44	0.015	0.10–0.78
Herd size*
	Smaller (≤77)	reference
	Medium (80–590)	5.20	2.93	2.91	0.004	1.71–15.72
	Larger (≥750)	39.90	45.78	3.21	0.001	4.21–378.14
Fixed effect		Variance	β (SE)	95% CI
	Province	0.95	0.87	0.16–5.76

SE – standard error; z – Wald z statistic; CI – confidence interval; ^* – age group and herd size variables were categorised into three groups by values of ≤25^th, 25^th – 75^th and ≥75^th centile prior to analysis