M. Farewell, Daniel et T. Farewell, Vernon, Dirichlet negative multinomial regression for overdispersed correlated count data, Biostatistics (Oxford. Print) , 14(2), 2013, pp. 395-404
A generic random effects formulation for the Dirichlet negative multinomial distribution is developed together with a convenient regression parameterization.A simulation study indicates that, even when somewhat misspecified, regression models based on the Dirichlet negative multinomial distribution have smaller median absolute error than generalized estimating equations, with a particularly pronounced improvement when correlation between observations in a cluster is high.Estimation of explanatory variable effects and sources of variation is illustrated for a study of clinical trial recruitment.