**4. Statistical analysis**

Graph Pad Prism 9.4.1 software (Graph Pad Software, Inc., La Jolla, CA, USA) was used for statistical analysis. Given exploratory, pilot study, no sample size calculation was needed. Quantitative variables were expressed as mean values (MV) ± standard deviation (SD). Chi-squared test was used to compare the two of groups, in cases of qualitative variables expressed as percentages. The unpaired t test was calculated and p ≤ 0.05 was considered statistically significant, with confidence interval CI = 95%. Nonparametric Pearson's correlation test was also performed in order to establish the "r" coefficient, drawing the direction and magnitude of possible links between variables.
