Inference for time to event and sojourn time data under right censoring using reweighting approaches.

Abstract

INFERENCE FOR TIME TO EVENT AND SOJOURN TIME DATA UNDER RIGHT CENSORING USING REWEIGHTING APPROACHES Jie Fan June 16,2010 In this dissertation research, we aim to solve problems of two types of survival data, clustered survival data with potentially informative cluster size and sojourn time data. The methods for these two types of data are different. However, both data have right censored observations, and we use reweighting approaches to deal with the censoring issue. In the first part of the dissertation research, we consider marginal AFT models for correlated survival data with potentially informative cluster size. Informative cluster size means that the size of the correlated groups may be predictive of their survival characteristics. Two competing proposals, cluster-weighted AFT (CWAFT) marginal model and non-cluster-weighted AFT (NCW AFT) marginal model, are investigated. Simulation and theoretical results show that the CW AFT approach produces unbiased parameter estimation, but that the NCWAFT model does not when the cluster size is informative. We use probability-probability plots to investigate statistical properties of confidence intervals and adopt Wald tests to examine power properties for the CW AFT model. To illustrate our analysis, we apply the CWAFT model to a dental study data set.