Results of the logistic regression for the case-control study.

(A) Odd ratios and their associated p-value for all the selected cases in the univariate models. Factors with P<0.05 are considered as significant (*). Factors with a P<0.25 are entered in the multivariate model (†).
(B) Odd ratios and P-values for the final multivariate model. Previous steps, consisting in removing one by one the factors with the highest P-value at each step, are not shown. The program used to execute the analysis gave P = 0.0000 for the overall model fit equal to 0.0000.
aAnimals are grouped into four density groups (see File S1) and the odds ratio indicates the relative amount by which the odds of the outcome changes when the value of the predictor value is increased by 1.0 unit.