Cross-cultural adaptation and validation of the Newest Vital Sign (NVS) health literacy instrument in general population and highly educated samples of Brazilian adults.

OBJECTIVE: The present work aimed at cross-cultural adaptation and validation of the health literacy assessment tool Newest Vital Sign (NVS) in general population (GP) and highly educated (HE) samples of Brazilian adults. DESIGN: An expert committee reviewed the translation and back-translation processes and the cultural adaptation. The construct validity was analysed with confirmatory factor analysis and via associations with features of the study population. SETTING: The final validation test was performed in two different populations from Londrina, a large town in southern Brazil. SUBJECTS: Brazilian adults: GP (adult clients of community pharmacies; n 189) and HE (public school teachers; n 301). RESULTS: The tool under validation showed good cross-cultural adaptation and internal consistency, with Cronbach's α of 0·75 for GP and 0·74 for HE. Confirmatory factor analysis showed acceptable models and identified two independent factors according to the relationship between components and numeracy for both GP and HE data. According to the Brazilian Portuguese version of the NVS instrument (NVS-BR), 48·7 % of GP and 33·5 % of HE presented adequate health literacy; this condition was inversely associated with age for both populations and directly correlated with educational level for GP. CONCLUSIONS: The NVS-BR showed good validity in two different populations of Brazilian adults and can be considered an alternative in screening for inadequate health literacy.