2.5. Statistical Methods
Categorical data were represented by absolute and relative frequencies. Differences in categorical data between independent groups were tested with the 2-tailed test and, if necessary, with Fisher’s exact test. Differences between measurements were tested with the McNemar–Bowker test or the marginal homogeneity test. The normality of the distribution of numerical variables was tested with the Shapiro–Wilk test. The median and the limits of the interquartile range describe continuous data. To test the differences of continuous variables between two independent groups (comparison between groups with and without contact), the Mann–Whitney U test was used, and between measurements, the Friedman test (post hoc Conover test). Spearman’s correlation coefficient was used to express the assessment of connection. All 