A computer program for the statistical analysis of repeated event data using a mixed effects regression model

This paper presents a computer program for fitting mixed effects regression models to repeated events data. The method has been described by Abu-Libdeh, Turnbull and Clark (Biometrics 46 (1990) 1017-1034). Such data can occur in longitudinal studies where subjects experience repeated events over time. The program allows the stepwise construction of a series of regression models which can be used to examine and test the influence of the various measured covariates upon the event rates. Two examples are provided. The first is a simple example involving the incidence of mammary tumors in rats. The second involves a very large complex data set from a clinical trial for the prevention of recurrent skin tumors.