Introduction

In the foregoing chapters many research questions have been addressed and many techniques for the analysis of longitudinal data have been discussed. In the examples, the relatively “simple” statistical techniques were performed with SPSS, while the generalized estimating equations (GEE) analyses and the mixed model analyses were performed with Stata. This chapter provides an overview of a few major software packages (i.e. SPSS, SAS, R, and MLwiN) and their ability to perform sophisticated longitudinal data analysis. In this chapter, only GEE analysis and mixed model analysis will be discussed. Multivariate analysis of variance (MANOVA) for repeated measurements can be performed with all major software packages, and can usually be found under the repeated measurements option of the generalized linear model (GLM) or as an extension of the (M)ANOVA procedure. The emphasis of this overview is on the output and syntax of the sophisticated longitudinal analysis in the different software packages, and especially is on the comparison of the results obtained with the various different packages. In this overview, only an-alysis with a continuous and a dichotomous outcome variable will be discussed in detail.