2.6. Statistical Analysis
For continuous variables, arithmetic means and standard deviations were calculated. For categorical variables, relative frequencies were calculated. The Mann–Whitney non-parametric test was applied to examine differences between the study groups for quantitative parameters; all the hypotheses were one-tail. Pearson chi-square and Fisher’s exact test were applied to examine correlations between the study and control groups of the categorical parameters. The sample size was determined by statistician consultation. A 