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A transition model for ordinal response data with random drop-out:An application to fluvoxamine data

Rezaei, Z and Ganjali, M and Berridge, Damon (2009) A transition model for ordinal response data with random drop-out:An application to fluvoxamine data. Journal of Biopharmaceutical Statistics, 19 (4). pp. 658-671. ISSN 1054-3406

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Abstract

Many methods are available to analyze incomplete longitudinal ordinal responses. In this paper a general transition model is proposed for longitudinal ordinal responses with random dropout. Maximum likelihood estimates are obtained for the transition probabilities when there are repeated observations. The likelihood function of the general model is partitioned to make possible the use of existing software to estimate model parameters. Some reduced forms of the model are also considered where for estimation of parameters in these models one has to use numerical optimization methods. The approach is applied to the well-known Fluvoxamine data. For these data, two important results, which have not been previously reported, are obtained: (1) some transition probabilities are estimated to be zero and (2) the model for current response, which conditions on previous response, removes the effects of some covariates that had previously been significant.

Item Type: Article
Journal or Publication Title: Journal of Biopharmaceutical Statistics
Uncontrolled Keywords: Backward approach ; Cumulative logit model ; Gamma ; Longitudinal ordinal response data ; Partial Correlation ; Random dropout
Subjects: UNSPECIFIED
Departments: Faculty of Science and Technology > Mathematics and Statistics
ID Code: 49433
Deposited By: ep_importer_pure
Deposited On: 05 Aug 2011 14:01
Refereed?: Yes
Published?: Published
Last Modified: 03 Jun 2014 09:50
Identification Number:
URI: http://eprints.lancs.ac.uk/id/eprint/49433

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