2.5 Data analysis
The Student’s t-test or the Mann-Whitney test were used to compare continuous variables between the groups. To compare categorical variables the Chi-square test or Fisher’s exact test was performed.
To determine the effect size of the intervention, continuous variables were expressed as mean and standard deviation, mean difference and 95% confidence interval, or median and interquartile interval (25% - 75%). The categorical variables were expressed in frequency and number of cases. When relevant, the relative risk was calculated. Kolmogorov-Smirnov normality test was performed for data distribution analysis. Per-protocol analysis was performed. P < 0,05 was considered for statistical significance.
All data analysis was performed in SigmaPlot 12.0 (Systat Software, Inc., Germany) and IBM SPSS Statistics Software 25.0 (Statistical Package for the Social Sciences).