Cox Proportional Hazards Model

A semiparametric survival model in which the hazard function at time t for an individual equals an unspecified baseline hazard multiplied by an exponential function of covariates (hazard(t|X) = h0(t) exp(βX)); it models the relative instantaneous risk of a time-to-event outcome and accommodates right-censoring without specifying the baseline hazard form, under the proportional hazards assumption t