Descriptive statistics were computed for all variables. The findings are reported with medians and quartiles to describe ordinal data (deviated from normal distribution, except age) and frequencies and percentages to describe group proportions. HY stage IV (n = 56) and stage V (n = 6) were merged due to reasons of distribution. Non-parametric tests (the Kruskal-Wallis test and/or Mann-Whitney U-test for ordinal variables) or the Chi-Square test for dichotomous or categorical variables were used for sub-group comparisons. Initially, the Kruskal-Wallis or the Chi-Square tests were used for comparisons of more than two sub-groups. If the p-value then was statistical significant, subsequent tests (Mann-Whitney tests or additional Chi-Square tests) were corrected for multiple comparisons, using the Bonferroni Correction.
All p-values reported are based on two-tailed comparisons where applicable; the alpha level of significance was set at 0.05; p-values were presented exactly except when below 0.001. All statistical analyses were computed by using SPSS v. 22 software for Windows (IBM Corporation, Armonk, NY, United States).
All p-values reported are based on two-tailed comparisons where applicable; the alpha level of significance was set at 0.05; p-values were presented exactly except when below 0.001. All statistical analyses were computed by using SPSS v. 22 software for Windows (IBM Corporation, Armonk, NY, United States).