Statistical analysis
Continuous variables are expressed as mean +/- SD, or median and interquartile range (IQR). Two-sided unpaired Student t -test was used to compare continuous variables that satisfied the normality assumption. Non-parametric Wilcoxon test was used for data that deviated from normality. Categorical and binary variables are presented as frequencies (percentages). Chi-square and Fisher exact test were used to compare the frequency distribution of categorical variables. Analysis of variance (ANOVA) was used to analyse the differences among group means. Two-tailed values of P < 0.05 were considered statistically significant. The IBM SPSS Statistic version 25 software was used for the statistical analysis (SPSS, Chicago, Illinois).