2.4. Data Management and Statistical Analysis
The Data Coordinating Center for this study was the Collaborative Center for Statistics in Science at Yale University in New Haven, Connecticut. The Data Coordinating Center was responsible for data management (including the data entered at each participating center) and data analysis. Since the number of patients for this study was minimal, descriptive statistics was used. Data are expressed as mean ± SD, or median (interquartile range) for the continuous variables within each treatment group, and the Kruskal–Wallis test was used for testing differences among the continuous variables among the three groups. The Chi-square test and Fisher’s exact test were used to test the differences in the categorical variables. Analysis was done using the SAS version 9.4 software. Significance was defined as a 2-sided 