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College of Arts & Sciences
Department of Statistics


Samiran Sinha

Thursday, November 3, 2016 - 2:45pm

Statistics Department Colloquium

Location: LeConte College, Room 210

Samiran Sinha
Department of Statistics
Texas A&M University

Title: Errors-in-covariates in the Accelerated Failure Time Model

In this talk we consider fitting an AFT model to right censored data when a predictor variable is subject to measurement errors. It is well know that without measurement errors, estimation of the model parameters in the AFT model is a challenging task due to the presence of censoring, especially when no specific assumption is made regarding the distribution of the logarithm of the time-to-event. The model complexity increases when a predictor is measured with error. We propose a nonparametric Bayesian method for analyzing such data. The novel component of our approach is to model 1) the distribution of the time-to-event, 2) the distribution of the unobserved true predictor, and 3) the distribution of the measurement errors all nonparametrically using mixtures of the Dirichlet process priors. Along with the parameter estimation we also prescribe how to estimate survival probabilities of the time-to-event. We illustrate the usefulness of the proposed method through limited simulation studies. Finally, we will discuss an application of the proposed method by analyzing a data set from an AIDS clinical trial study.

 


PDF icon Errors-in-covariates in the Accelerated Failure Time Model--Samiran Sinha