Table 6: Multivariable Cox proportional hazards model of weather related factors associated with the survival of M. bovis in the environment.

Risk factorParameter estimateStandard errorHazard ratio (95% confidence interval)

Temperature*0.060.021.06 (1.02–1.10)

*Results of purposeful selection of covariate and modified stepwise modeling in Cox regression. Only temperature remains in the model.