Table 3.

Results of multivariable Cox regression analysis revealing the risk variables significantly associated with the morbidity of layer chickens in Hawassa city.

Variable	Category	HR	P value	95% CI
Farm hygiene	Good	0.005	0.000	0.003, 0.009
	Poor
Farm experience	≥3 yrs.	0.435	0.002	0.254, 0.746
	<3 yrs.
Housing condition	Good	0.190	0.000	0.112, 0.325
	Poor
Age category	4–5 month	0.155	0.000	0.080, 0.302
	>5 month

HR = hazard ratio; CI = confidence interval.