Revisit Kaplan-Meier estimator in estimating QAL survival distributions

Quality-adjusted lifetime (QAL) is an important component in evaluation of clinical trials. In a seminal paper, Gelber et al. (1989) claimed that the Kaplan-Meier estimator is inconsistent in estimating the distribution of QAL under the presence of censoring. However, in this article, we show that, with appropriate censoring indexing, the Kaplan-Meier estimator actually is consistent in some practically important QAL data settings. Copyright © 2013 Grace Scientific Publishing, LLC