Data analysis
Continuous variables were tested for normal distribution using histogram
analysis. Data with a normal distribution are presented as the mean ±
standard deviation. Data without a normal distribution are presented as
the median and interquartile range (IQR). Categorical variables are
expressed as the number and ratio. The chi-square test was used to
compare categorical variables. Two-tailed P < 0.05 was
considered statistically significant. All statistical analyses were
performed using IBM SPSS statistics version 25 (IBM Inc., Armonk, NY,
USA).