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.

翻译：广义估计方程（GEE）方法是临床研究中分析纵向数据和聚类数据时广泛使用的统计方法。在牙科领域，由于从同一患者获得多个结果，个体患者产生的结果彼此相关。本研究聚焦于GEE的基本思想，介绍了协方差矩阵和工作相关矩阵的类型。采用拟似然信息准则（QIC）及其近似形式（QICu）来选择最佳工作矩阵和相关结果的最佳拟合模型。