A Confidence Interval for the Median Survival Time

A nonparametric asymptotic confidence interval for the median survival time is developed for the case where data are subject to arbitrary right censoring. This is accomplished by inverting a generalization of the sign test for censored data. A simulation study shows that this nonparametric confidence interval performs well for a variety of underlying survival functions. The procedure is applied to data from a clinical trial that compared f'our dosage regimens of 5-uorouracil.