Discerning - Version MIXPREG -Poisson Regression Analysis Software

MIXPREG provides maximum marginal likelihood estimates for mixed-effects Poisson regression analysis. These models can be used for analysis of correlated count data, for example, data arising from a clustered design. For clustered data, the mixed-effects model assumes that data within clusters are dependent. The degree of dependency is jointly estimated with the usual model parameters, thus adjusting for dependence resulting from clustering of the data. MIXPREG uses marginal maximum likelihood estimation, utilizing a Newton-Raphson iterative solution. Specifically, the Cholesky factor of the random-effects variance-covariance matrix is estimated along with the effects of model covariates.