Time-to-Event Analysis for Onset of Neurological Symptoms and for Survival Duration.^{1, 2}

1Testing Terms: In Kaplan-Meier analysis the Log-Rank test places more weight on later event times; the Wilcoxon test places more weight on early event times and is the optimum rank test if the error distribution is logistic. Prob>ChiSq lists the probability of obtaining, by chance alone, a Chi-square value greater than the one computed if the time-to-event functions are the same for all groups. In Cox proportional hazards analysis a Risk Ratio of 1.00 occurs when timing is likely identical in the two groups. The Effect Likelihood Test is the likelihood-ratio Chi-square test on the null hypothesis that the parameter estimate for the Treatment covariate is zero (no effect of treatment). Testing term descriptions are taken from the JMP® 7.0.1 Help file. 2A neurological score of two in both hind limbs is taken to be the definitive onset of neurological symptoms.