**4. Statistical Analysis**

in Table 4.

The statistical analysis of the results obtained in this study included descriptive statistics, distribution of the numbers with a percentage distribution, nonparametric tests (since data distribution obtained in a DASS test deviated from the normal distribution), U Mann–Whitney, as well as H Kruskal–Wallis tests with multiple comparisons test with Bonferroni correction. The distribution of the psychological variables was checked with the usage of analysis of histograms and the Shapiro–Wilk test in the Statistica program. The distribution in particular scales and the overall result deviated from the normal distribution, which was statistically significant. The effect size for the Kruskal–Wallis test was calculated as the eta squared based on the H-statistic: eta squared (H) = (H − k + 1)/(*n* − k); where H is the value obtained in the Kruskal–Wallis test; k is the number of groups; *n* is the total number of observations. To check the reliability of the applied test, the values of the Cronbach's alpha test coefficient for individual scales of the tool were calculated (using the Statistica v.13 program; Statistica software—Polish version from StatSoft Corporation Poland, the partner of Tibco Corporation, Palo Alto, California, USA (licence for Medical University of Lublin)). To determine the risk factors for developing higher intensity of emotional distress, we standardized the scores of the DASS-21 total score, and then we distinguished two groups of subjects for further comparisons. The first group of subjects included the respondents with low scores (DASS 0; below mean (M)—standard deviation (SD)), whereas the second group—those with high scores (above M + SD). Afterward, odds ratio (OR) values along with the significance level were calculated using the MedCalc Odds Ratio Calculator program.

The control groups were allocated to the particular variable as follows—for 'sex'—men in the DASS 0 and DASS 2 groups; for 'field of study' and 'I live with'—the whole DASS 0 and DASS 2 groups; for 'Do you have any chronic disease'—the respondents who answered 'No' in the DASS 0 and DASS 2 groups; for 'Did you use psychological/psychiatric help before the beginning of the pandemics?' and 'Did you use psychological/psychiatric help

during the pandemics'—the respondents who answered 'No' in the DASS 0 and DASS 2 groups; for 'What was the most difficult for you during pandemics?'—the respondents who answered 'I was not afraid' in the DASS 0 and DASS 2 groups; for 'Are you currently working'—the respondents who answered 'No, I do not work' in the DASS 0 and DASS 2 groups; for 'How do you assess your economic situation during pandemics?'—the respondents who answered 'I have a stable family income, nothing has changed' in the DASS 0 and DASS 2 groups.
