*2.2. Statistical Analysis*

The results of the study were statistically analyzed using the IBM SPSS Statistics v. 25 package 9 (IBM, Armonk, NY, USA). To assess the compliance of the empirical distributions obtained in the study with the theoretical normal distribution, typical for general population, the Shapiro–Wilk test for small groups (*n* < 50) and the Kolmogorov–Smirnov test for large groups were implemented. The non-parametric Spearman correlation was used to analyze the relationships between the continuous variables, and the non-parametric Mann–Whitney U test was used to assess the differences between the two independent groups. After standardizing the selected variables, the hierarchical regression model was also used, and the statistical significance index was established at *p* < 0.05.
