Covariates evaluated for an association with mortality in groups of cattle either administered zilpaterol hydrochloride (ZH) or not in the multi-feedlot ZH dataset in univariate and multivariable models.

Administration of ZH was associated with mortality (P<0.01) in all multivariable models.
*P value indicated was that observed at the time of removal from the multivariable model if >0.10, or if retained, i.e., ≤0.10, its value in the final multivariable model.
** Interaction term of the covariate with administration of ZH, i.e., evaluation of potential modification of the association between death loss and administration.