We will analyze the positive predictive value of a dichotomous prognostic marker (favorable or unfavourable SSEP). For this purpose, we will use two definitions of favorable outcome, i.e. a functional and a behavioral one. If outcome is defined with respect to independence in daily life, we will use a modified Rankin Scale score of 0-3 (no symptoms - moderate disability, but able to walk independently) to categorize a favorable functional outcome. In the context of a catastrophic event such as cardiac arrest with high likelihood of permanent VS, it is our experience that some patients and families consider regaining functional communications skills also a favourable outcome. In a separate analysis, we will therefore use the recovery of full consciousness as measured by the CRS-R to define a favorable behavioral outcome. To analyse the effect of covariates on functional and behavioral outcomes, we will use mixed effects regression models, including both fixed and random effects. This method of analyzing longitudinal data is highly effective to examine change trajectories with several unequally spaced waves of data. Covariates will be sociodemographic variables, prognostic variables and treatment factors (e.g. use of therapeutic hypothermia), adjusted for age and sex.