A step-by-step guide to generalized estimating equations using SPSS in the field of dentistry

The Generalized Estimating Equations (GEE) approach is a widely used statistical method for analyzing longitudinal data and clustered data in clinic studies. In dentistry, due to multiple outcomes obtained from one patient, the outcomes produced from individual patients are correlated with one another. This study focuses on the basic ideas of GEE and introduces the types of covariance matrix and working correlation matrix. The quasi-likelihood information criterion(QIC) and quasi-likelihood information criterion approximation(QICu) were used to select the best working matrix and the best fitting model for the correlated outcomes.