title: Modelling heterogeneity in clustered count data with extra zeros using compound Poisson random effect.
abstract: In medical and health studies, heterogeneities in clustered count data have been traditionally modeled by positive random effects in Poisson mixed models; however, excessive zeros often occur in clustered medical and health count data. In this paper, we consider a three-level random effects zero-inflated Poisson model for health-care utilization data where data are clustered by both subjects and families. To accommodate zero and positive components in the count response compatibly, we model the subject level random effects by a compound Poisson distribution. Our model displays a variance components decomposition which clearly reflects the hierarchical structure of clustered data. A quasi-likelihood approach has been developed in the estimation of our model. We illustrate the method with analysis of the health-care utilization data. The performance of our method is also evaluated through simulation studies.
authors.affiliation: Department of Mathematics and Statistics, University of New Brunswick, Fredericton, NB, Canada E3B 5A3. renjun@unb.ca
authors.forename: Renjun
authors.initials: R
authors.lastname: Ma
authors.forename: M Tariqul
authors.initials: MT
authors.lastname: Hasan
authors.forename: Gary
authors.initials: G
authors.lastname: Sneddon
mesh_terms: D001699:Biometry; D016000:Cluster Analysis; D003695:Delivery of Health Care / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D008137:Longitudinal Studies; D008297:Male; D015233:Models, Statistical; D016012:Poisson Distribution; D012044:Regression Analysis