Data Analysis
Owing to a relatively small number of children in both study groups, post hoc power analysis was performed to evaluate the reliability of the results. Assuming at least noninferiority between the study groups, the required sample sizes were calculated to attain 80% statistical power on 95% significance level with 10 points as a noninferiority margin using the observed group means and pooled SD. We chose a 10-point difference because we were interested in clinically significant difference that might affect the performance of the children. In this setup, we found that sufficient total sample size to assess noninferiority for FSIQ is n = 95 subjects and for PRI n = 216 subjects. This analysis was performed using R: a language and environment for statistical computing, version 4.2.3 (R Foundation for Statistical Computing, Vienna, Austria) and epiR package, version 2.0.57 (Stevenson et al.).The Kolmogorov-Smirnov test was used to analyze whether the variables were normally distributed, and the Shapiro-Wilk test was used to test the normality of the subgroups of boys and girls (n < 50). Continuous variables are described using means, SDs or medians, and interquartile ranges (IQR). Categorical variables are described using frequencies and percentages. Between-group comparisons in continuous variables were performed using Student's 