The following R-code may be used for computing likelihood based confidence intervals for the median residual life.
Definition of the median residual life
The median residual life (or median remaining lifetime) of a unit at time t is given by:
where mdrl is the median residual life, and S(·) the survival function of the failure times.
Computing likelihood based intervals for MDRL
The method for computing the likelihood based confidence interval for the median residual life is similar to the one I previously used for the mean residual life (this blog post explains the method for computing the likelihood based confidence intervals for the mean residual life).