Evaluating Percentiles of Survival

To the Editor: Findings from observational studies of time to an event of interest (eg, death, incidence, relapse) are commonly presented in terms of hazard ratios or rate ratios. These are relative measures of risk. A patient or health scientist, however, may also be interested in knowing the absolute risk of having the event of interest after a given time point. Survival percentiles provide this information. For example, if the 50th percentile...