Transformation Models for Survival Data Analysis and Applications

It is often assumed that all uncensored subjects will eventually experience the event of interest in standard survival models. However, in some situations when the event considered is not death, it will never occur for a proportion of subjects. Survival models with a cure fraction are becoming popul...

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Bibliographic Details
Other Authors: Liu, Yang, 1979- (authoraut)
Format: Others
Language:English
English
Published: Florida State University
Subjects:
Online Access:http://purl.flvc.org/fsu/fd/FSU_migr_etd-1155
Description
Summary:It is often assumed that all uncensored subjects will eventually experience the event of interest in standard survival models. However, in some situations when the event considered is not death, it will never occur for a proportion of subjects. Survival models with a cure fraction are becoming popular in analyzing this type of study. We propose a generalized transformation model motivated by Zeng et al's (2006) transformed proportional time cure model. In our proposed model, fractional polynomials are used instead of the simple linear combination of the covariates. The proposed models give us more flexibility without loosing any good properties of the original model, such as asymptotic consistency and asymptotic normality of the regression coefficients. The proposed model will better fit the data where the relationship between a response variable and covariates is non-linear. We also provide a power selection procedure based on the likelihood function. A simulation study is carried out to show the accuracy of the proposed power selection procedure. The proposed models are applied to coronary heart disease and cancer related medical data from both observational cohort studies and clinical trials === A Dissertation Submitted to the Department of Statistics in Partial FulfiLlment of the Requirements for the Degree of Doctor of Philosophy. === Spring Semester, 2009. === March 23, 2009. === Cure Rate Models, Survival Models === Includes bibliographical references. === Xu-Feng Niu, Professor Directing Dissertation; Donald Lloyd, Outside Committee Member; Dan McGee, Committee Member; Debajyoti Sinha, Committee Member.