American Statistical Association New York City Metropolitan Area Chapter Mailman School of Public Health Columbia University Department of Biostatistics Colloquium

We propose a general multistate model. The model is developed for the analysis of repeated episodes of multiple states representing different health status. Different types of transition are described by flexible transition-specific nonparametric baseline intensities. Transitions among multiple states are modeled jointly using multivariate latent traits with factor loadings. A state-specific latent trait is used to capture individual tendency of the sojourn in the state that cannot be explained by covariates and to account for correlation among repeated sojourn in the same state within an individual. Correlation among sojourns across different states within an individual is accounted for by the correlation between the different latent traits. The factor loadings for a latent trait accommodate the dependence of competing transitions to different states from a same state. The method is illustrated by studying repeated transitions between independent and disabled states of activities of daily living (ADL) with death as an absorbing state in a longitudinal aging study.