Table 4

Multivariable analysis showing association between congenital hereditary sensorineural deafness (CHSD) in Australian Cattle Dogs (n = 534) and sex, mask and pigmented body spots from a multilevel logistic model and an animal model
Variable Multilevel logistic model* Logistic animal model**
Adjusted odds ratio (95% CI)† P-value Adjusted odds ratio (95% CI)† P-value
Sex 0.032 0.036
 Male Reference category Reference category
 Female 2.0 (1.0 to 3.8) 0.035 1.9 (1.1 to 3.6) 0.034
Mask <0.001 ***
 No Reference category Reference category
 Left 0.9 (0.4 to 2.2) 0.807 0.9 (0.4 to 2.1) 0.775
 Right 1.1 (0.5 to 2.7) 0.765 1.0 (0.4 to 2.4) 0.915
 Bilateral 0.2 (0.1 to 0.5) <0.001 0.2 (0.1 to 0.5) <0.001
Pigmented body spot 0.023 0.052
 None Reference category Reference category
 At least one 0.3 (0.1 to 0.9) 0.038 0.4 (0.1 to 1.0) 0.050

Sex mask and pigmented body spot were simultaneously fitted in multivariable models. The odds ratios are for having at least one deaf ear rather than normal hearing. These analyses demonstrate that these three variables were each independently associated with CHSD.

* Multilevel logistic models with dog fitted within litter within kennel of birth. Bolded P-values are overall likelihood ratio test P-values; unbolded P-values are Wald P-values for each coefficient.

** Logistic animal (‘threshold’) models using the full pedigree (ie all pedigree data that were available), with dog fitted as a random effect with a numerator relationship matrix. Bolded P-values are overall Wald P-values; unbolded P-values are Wald P-values for each coefficient.

*** Overall p-value for mask in logistic animal model not calculated.

† 95% CI indicates 95% confidence interval.

Sommerlad et al.

Sommerlad et al. BMC Veterinary Research 2012 8:202   doi:10.1186/1746-6148-8-202

Open Data