Statistical analysis
All statistical analyses were performed using SPSS software (version 26.0, USA). Continuous variables are presented as mean ± standard deviation. Categorical variables are presented as numbers or percentages. Fisher's exact test was used to assess categorical variables. The normality of continuous variables was assessed using the Shapiro–Wilk test. For normally distributed continuous variables, independent-sample t-tests were used for analysis. For non-normally distributed continuous variables, the Mann–Whitney U test was employed for analysis. The significance level for all statistical tests was set at p < 0.05.