2.4 Statistical data analysis
Normality of data distributions were examined with the
Kolmogorov-Smirnov test. Continuous variables are expressed as mean ± SD
or median with interquartile range as appropriate, and categorical
variables are expressed as a percentage. For the continuous variables,
comparisons between two groups were made using t-tests while for 3 or
more groups with ANOVA and Bonferroni test for multiple comparisons. All
the analyses were conducted in SPSS version23 [SPSS Inc., Chicago, IL,
USA], Microsoft Windows version, and P ≤ 0.05 from 2-sided
tests was considered statistically significant.