Statistical analysis
The data are presented as median (interquartile range). Continuous
variables were compared by Wilcoxon rank-sum test. Categorical variables
were compared by an χ2 test or Fisher’s exact test.
Significant differences were further evaluated by using Bonferroni’s
method for pairwise multiple comparisons. A P-value < 0.05 was
considered statistically significant. All statistical analyses were
performed with R software (The R Foundation for Statistical Computing,
Vienna, Austria).