. 2023 May 29;64(9):552–560. doi: 10.1111/jsap.13623

Table 5.

Multi‐variable logistic regression modelling steps for the investigation of risk factors for feline calicivirus (FCV) infection in the 430 cats for which a complete data set were available. Factors with a P‐value ≤0.2 from the univariable analysis were taken forward into building the model. Correlation between independent variables was assessed by multi‐collinearity (tolerance values >0.1). The model was built using a backward elimination process (likelihood ratio test) with selection of independent variables for removal based on minimising the log‐likelihood‐ratio statistic

		Standard error	Wald test	Significance	^e Exp(B)	95% confidence interval for ^e Exp(B)
		Standard error	Wald test	Significance	^e Exp(B)	Lower	Upper
Step 1	Purebred ^a	0.309	7.804	0.005	2.371	1.294	4.345
	Sex	0.296	1.927	0.165	1.509	0.844	2.698
	Neutered by Q3	0.584	2.289	0.130	2.421	0.770	7.607
	Multi‐cat ^b at Q3	1.034	3.260	0.071	6.467	0.852	49.052
	Cat flu ^c	0.847	0.982	0.322	2.315	0.440	12.179
	Clinical signs ^d	0.979	0.160	0.689	1.479	0.217	10.064
Step 2	Purebred ^a	0.307	8.111	0.004	2.400	1.314	4.383
	Sex	0.295	1.852	0.174	1.494	0.838	2.665
	Neutered by Q3	0.583	2.182	0.140	2.367	0.755	7.422
	Multi‐cat ^b at Q3	1.033	3.328	0.068	6.589	0.869	49.948
	Cat flu ^d	0.459	5.927	0.015	3.056	1.243	7.510
Step 3	Purebred ^a	0.306	7.975	0.005	2.372	1.302	4.319
	Neutered by Q3	0.575	2.715	0.099	2.578	0.836	7.949
	Multi‐cat ^b at Q3	1.033	3.260	0.071	6.460	0.853	48.945
	Cat flu ^d	0.456	5.855	0.016	3.015	1.233	7.369
Step 4	Purebred ^a	0.303	8.984	0.003	2.480	1.369	4.491
	Multi‐cat ^b at Q3	1.030	3.064	0.080	6.069	0.806	45.713
	Cat flu ^d	0.455	5.753	0.016	2.979	1.221	7.268

Note: Significance shows the P‐value associated with each predictor variable; Q3, questionnaire three (filed at 12 months age)

^{^a}

Cats were categorised as “crossbred” if reported by the owner to be domestic shorthair/longhair or cross‐breed and as “purebred” if reported by the owner to be a specific breed other than the domestic breeds or crosses

^{^b}

Multi‐cat, living with one or more other cat

^{^c}

Cat Flu, current or historical diagnosis of cat flu with or without veterinary confirmation

^{^d}

Clinical signs, current or historical presence of clinical signs supportive of upper respiratory tract disease

^{^e}

Exp(B), exponential of unstandardised beta coefficients