*2.5. Data Analysis*

Investigation of psychometric properties of the adapted RIFL-P instrument included inter- and intra-rater reliability (Pearson correlation coefficient), item-level descriptive statistics, and confirmatory factor analysis (CFA). The internal consistency of the adapted version was computed using Cronbach's alpha.

To examine convergent validity, the composite score of RIFL-P was correlated with the scores of the PICCOLO Brazilian Portuguese version, Five Stimulation Markers, and INTER-NDA scales. Discriminant validity was tested by examining the relationship between gender and the RIFL-P scores and no significant association was expected. Different types of correlation were used dependent on variable type (Pearson product-moment correlation for continuous variables, point-biserial correlation for binary and continuous variables, and Spearman's correlation for ordinal variables). Statistical analyses were conducted using the Statistical Package for Social Sciences (SPSS, Inc., Chicago, IL, USA) for Windows (version 21.0; Microsoft Corporation, Redmond, WA, USA), and the Stata® version 13.0 software.
