Statistical analysis
Medians were used as measures of central tendency. Comparisons between
two groups were performed using the Mann–Whitney U test for
non-normally distributed variables. The comparison between groups was
evaluated using the Kruskal–Wallis test. Correlation analysis was
performed using pointwise point biserial correlation analysis. All
statistical analyses were performed using GraphPad Prism version 8.0 for
Windows (GraphPad Software, Inc., San Diego, CA, USA).