2.6. Statistical Methods
Basic descriptive statistics and statistical tests according to the type of data were used for statistical evaluation. The normality of the data was tested using the Shapiro–Wilk test, followed by a two-sample t-test and a non-parametric Mann–Whitney test, paired Wilcoxon test, and Spearman correlation coefficient. For qualitative data, the chi-square test was used; if the conditions for its use were not met, Fisher’s exact test was used. Statistical tests were evaluated at the level of significance of 5%. Stata version 17 was used for processing.