Statistical package for the social sciences spss statistical software version 23

To discern the mean effect of the numeric variables of the three independent groups, with the significance level of 0.05, power 0.8, and the effect size 0.29, the minimum sample size required was 111 subjects (37 subjects per group) (calculated by G * Power 3.1.2, Franz Faul, University of Kiel, Germany) [25 (link)]. Regarding the statistical analysis of the results, categorical data were represented by absolute and relative frequencies. Numerical data were described by median and interquartile range, in case of deviation from the normal distribution. The variance of the category variables was tested by the Chi-square test and Fisher’s exact test. The differences between variables in two independent groups were tested by the Mann–Whitney U Test. The differences between three UI groups were tested by the Kruskal–Wallis test. The correlation between numeric variables was evaluated by Spearman’s correlation coefficient ρ (rho). All P values were two-sided. The level of significance was set to Alpha = 0.05. The statistical analysis was conducted using the MedCalc Statistical Software version 18.2.1 and the International Business Machines Corporation (IBM) Statistical Package for the Social Sciences (SPSS) statistical software, version 23 [26 ,27 ].