Statistical analysis To estimate the effects of the different educational interventions tested, intention to treat analysis was used. Initial univariate differences among groups for quantitative data were analyzed by one-way ANOVA (Bonferroni post hoc test). Factorial ANOVA and two-way ANOVA models (Bonferroni post hoc test) were used to assess the differences among groups along the study. ANOVA was also used to explore initial vs. end-of-study differences among quantitative data. Differences among qualitative measures were explored by Chi-squared (Yates corrected). P values of less than 0.05 were considered as significant (two tailed). Missing data strategies applied to the primary endpoint were last observation carried forward and complete case analysis. Both strategies were compared to evaluate the impact of missing data on the efficacy analysis of the primary endpoint.