Article first published online: 19 JUL 2012
Copyright © 2012 John Wiley & Sons, Ltd.
Statistics in Medicine
Volume 31, Issue 29, pages 4049–4060, 20 December 2012
How to Cite
Das, K. and Chakraborty, A. (2012), Robust analysis in joint models: an application to a study on muscular dystrophy. Statist. Med., 31: 4049–4060. doi: 10.1002/sim.5502
- Issue published online: 23 NOV 2012
- Article first published online: 19 JUL 2012
- Manuscript Accepted: 1 JUN 2012
- Manuscript Received: 30 NOV 2010
- UGC, India. Grant Number: F. 37-547/2009 (SR)
- partial ordinal model;
- influential observations
Generalized partial ordinal models occur frequently in biomedical investigations where, along with ordinal longitudinal outcomes, there are time-dependent covariates that act nonparametrically. In these studies, an association between such outcomes and time to an event is of considerable interest to medical practitioners. The primary objective in the present article is to study the robustness of estimators of the parameters of interest in a joint generalized partial ordinal models and a time-to-event model, because in many situations, the estimators in such joint models are sensitive to outliers. A Monte Carlo Metropolis–Hastings Newton Raphson algorithm is proposed for robust estimation. A detailed simulation study was performed to justify the behavior of the proposed estimators. By way of motivation, we consider a data set concerning longitudinal outcomes of children involved in a study on muscular dystrophy. Our analysis revealed some interesting findings that may be useful to medical practitioners. Copyright © 2012 John Wiley & Sons, Ltd.