MEASURING PHYSICAL ACTIVITY IN BRAZILIAN YOUTH: REPRODUCIBILITY AND VALIDITY OF THE PAQ-C AND PAQ-A

Introduction: The Physical Activity Questionnaire for Children (PAQ-C) and the Physical Activity Questionnaire for Adolescents (PAQ-A) were originally developed to provide self-reported measurements associated with the practice of physical activity by youth. Objectives: To translate into the Portuguese language, make a cross-cultural adaptation and analyze the reproducibility and concurrent validity of the PAQ-C and PAQ-A in a sample of Brazilian youth. Methods: Original questionnaires were translated following the international recommendations. Translated questionnaires were administered to a sample of 528 youth (285 girls and 243 boys) aged 8-18 years-old. Reproducibility was obtained by reapplying the same questionnaire after an interval of one week, through intraclass correlation coefficient (ICC) and the Bland-Altman technique. Cronbach's alpha coefficient was used to analyze the internal consistency of the questionnaires. To evaluate concurrent validity, information provided by a RT3 accelerometer over a period of 7 days was used as the reference criterion. Total physical activity (total PA) and moderate and vigorous physical activity (MVPA) derived from the accelerometer were compared using Spearman's correlation coefficient with the scores produced by the questionnaires. Results: After minor changes identified in the translation process, a panel of experts considered that the Portuguese version of PAQ-C and PAQ-A showed semantic, idiomatic, cultural and conceptual equivalence. Test-retest reproducibility showed ICC ranged from 0.68 to 0.88. The Bland-Altman technique showed a high matching capacity between applications of the same questionnaire one week apart. Internal consistency showed alpha = 0.71 and alpha = 0.76, respectively. The scores produced by the questionnaires showed moderate correlations with total PA (rho = 0.40; rho = 0.50) and MVPA (rho = 0.48; rho = 0.54) estimated by the accelerometer. Conclusion: The translation, cross-cultural adaptation, reproducibility and concurrent validity of the PAQ-C and PAQ-A were satisfactory, enabling their application in future studies in Brazil.