Data analysis
We used SPSS (IBM Corp. IBM SPSS Statistics for Windows, Version 19.0. Armonk, NY: IBM Corp.) for statistical analysis. A Mann-Whitney U test was used for continuous data and chi-square test/Fisher’s exact test was used for categorical data. A Wilcoxon signed-rank and Mann-Whitney U tests were utilized for assessing intra-group and inter-group data at the varying follow-up time points. The 2-way ANOVA was used to test the group by time interaction. Significance was determined asp <0.05.