%yoll
The SAS YOLL macro uses PROC PHREG to compute the time from a specific start time (or age) to an outcome (expected time after the start time to the outcome) or the time from the outcome to a specific time (or age) (expected time lost before the end time). It bootstraps to get the confidence bounds on these values. It computes these values for different levels of an exposure at specified values of the covariates.