Cox proportional hazards model

A Cox proportional hazards model is a type of regression model used to analyze the time at which an event of interest occurs. It is a non-parametric model used to estimate the effect of one or more predictor variables on a response variable, which is the time to the occurrence of an event. The model produces a hazard ratio, which is the ratio of the hazard rate corresponding to one level of a predictor relative to the rate corresponding to a reference level of the predictor. The hazard ratio can be used to assess the effect of a particular predictor on the time to the event of interest, allowing you to compare the risk among different individuals or groups. The model also allows for adjustment of other covariates that may influence the relationship between a predictor and time to the event.