Spring 2016
Seminars are held on Thursdays in Cullimore Hall. For questions about the seminar schedule, please contact Antai Wang.
Date: April 21, 2016
Speaker: Sharon Xiangwen Xie
Department of Biostatistics and Epidemiology,
University of Pennsylvania
Title: "Survival Analyses with Missing Outcomes"
Abstract:
When a true survival endpoint cannot be assessed for some subjects, an alternative endpoint that measures the true endpoint with error may be collected, which often occurs when obtaining the true endpoint is too invasive or costly. We develop an estimated likelihood function for the situation where we have both uncertain endpoints for all participants and true endpoints for only a subset of participants. We propose a nonparametric maximum estimated likelihood estimator of the discrete survival function of time to the true endpoint. We show that the proposed estimator is consistent and asymptotically normal. We demonstrate through extensive simulations that the proposed estimator has little bias compared to the naive Kaplan-Meier survival function estimator, which uses only uncertain endpoints, and more efficient with moderate missingness compared to the complete-case Kaplan-Meier survival function estimator, which uses only available true endpoints. We illustrate the proposed method by estimating the risk of developing Alzheimer’s disease using data from the Alzheimer’s Disease Neuroimaging Initiative.
*This is a joint work with Jarcy Zee.