Statistical analysis
Statistical Package for the Social Sciences 23.0 (IBM, New York, USA) was used for the analysis with the distribution examined using the Shapiro-Wilk test and Q-Q plots. The continuous variables are expressed as median and interquartile range, and were compared by Mann-Whitney U test, and the categorical variables are expressed as percentage and frequency, and were compared by chi-squared or Fisher’s exact test. Logistic regression was used for the correlation, and p<0.05 was considered statistically significant.