Modelling of Correlated Ordinal Responses, by Using Multivariate Skew Probit with Different Types of Variance Covariance Structures

In this paper, a multivariate fundamental skew probit (mfsp) model is used to modelcorrelated ordinal responses which are constructed from the multivariate fundamentalskew normal (mfsn) distribution originate to the greater flexibility of mfsn. toachieve an appropriate vc structure for reaching reliable statistical inferences, manytypes of variance covariance (vc) structures are considered to model mfsn.simulation methods are used to find the properties of the parameters estimate. theschizophrenia collaborative study data invokes the proposed mfsn model. the resultsconfirm that the first-order autoregressive (ar(1)) structure substantially enhances theestimation of the parameters. furthermore, over time the drugs effect the schizophrenia treatment, noticeably.