Breaking Free from the Hazard Ratio: Embracing the Restricted Mean Survival Time in Clinical Trials

The Cox model estimates the ratio of the hazard of the outcome of interest (e.g., the time to death) between two treatment groups. The hazard is defined as the instantaneous probability of experiencing the event of interest in the next time interval among individuals who had not yet experienced the event. As a statistical measure, the hazard ratio can be difficult to interpret.