Model Fitting in PROC GENMOD

There are several procedures in the SAS System for statistical modeling. Most statisticians who use the SAS system are familiar with procedures such as PROC REG and PROC GLM for fitting general linear models. However PROC GENMOD can handle these general linear models as well as more complex ones such as logistic models, loglinear models or models for count data. In addition, the main advantage of PROC GENMOD is that it can accommodate the analysis of correlated data. In this paper, we will discuss the use of PROC GENMOD to analyze simple as well as more complex statistical models. When other procedures are available to perform the same analysis, we will highlight the options from these procedures that may be missing in PROC GENMOD but might be of interest to the user. An example is given showing how PROC GENMOD is used to analyze various types of endpoints (continuous and count data) from a toxicology experiment. The materials in this paper should be accessible even to those users with limited data analysis skills.