2.6. Statistical analysis
Data were collected prospectively. Categorical variables were tabulated as numbers with percentages. Continuous variables were shown as median values, with corresponding IQR. Analysis of the normal distribution of data (Kolmogorov-Smirnov test) was performed and, according to the results, appropriate non-parametric statistical analysis was performed. Differences among continuous variables ​​were analysed using t-test and Mann-Whitney U test. Differences in categorical variables were analysed using Fisher’s exact test. Difference between the groups was considered significant at the level of 0.05. Statistical analysis was performed using the licensed software IBM SPSS Statistica (version 25.0. www.statsoft.com, StatSoft, Inc. 2017).