Transcultural adaptation of Patient-Reported Outcomes in Obesity (PROS) questionnaire for Brazil

Objective: To perform a cross-cultural adaptation and validation in the Brazilian cultural context of questionnaire Patient-Reported Outcomes in Obesity (PROS). Methods: The cross-cultural adaptation process involved the translation from original English language into Brazilian Portuguese by two qualified and independent translators. The back-translation was performed by two English language teachers who were native speakers, without any medical knowledge of the original scale. An expert committee was created with researchers to assess semantic, idiomatic, experiential and conceptual equivalence. The pre-test of the Brazilian version, named PROS-Br, was carried out with ten adults with obesity. To assess the psychometric properties of the instrument, a cross-sectional epidemiological study was carried out. The population consisted of 120 Brazilian adults with obesity who went to the appointment at a school-clinic. The Item Response Theory and Factor Analysis with Principal Component Extraction was used for the psychometrics analysis. To measure reliability, the alpha-Cronbach indicator was used. Results: In the reliability analysis, alpha-Cronbach was 0.82. Two factors explained 58.3% of the total variance in the principal component analysis, involving behavioral and physical aspects. Item Response Theory curves showed that all questions have discriminatory characteristics, pointing to the adequacy of the proposed version. Conclusion: The Brazilian version was proven valid and reliable to measure the quality of life of individuals with obesity, allowing one to develop intervention strategies, plan and execute actions at services and for public health policies.