2.5. Statistical analysis
The data was processed using Statistica TIBCO Software Inc. (2017) version 13.3 soft-ware, which was licensed by the Medical University of Silesia in Katowice. To assess the normality of distributions, we used the Shapiro-Wilk test. Values are presented as means and 95% confidence intervals or medians with Q1–Q3 values. To compare quantitative variables the t-test for independent means and t-test for dependent means were used. To compare independent variables with an abnormal distribution U Mann- Whitney test was used. For dependent variables we used Wilcoxon test. We assumed a p-value of less than 0.05 was statistically significant. We also use Spearman rank correlation to assess the relationship between variables. We assumed a p-value of less than 0.05 was statistically significant.