Validity of indicators on physical activity and sedentary behavior from the Brazilian National School-Based Health Survey among adolescents in Rio de Janeiro, Brazil

This study evaluated the relative validity of physical activity indicators from the questionnaire used in the Brazilian National School-Based Health Survey (PeNSE) in the city of Rio de Janeiro, Brazil, based on a sample of 174 students. The following indicators of weekly physical activity were evaluated: ACTIVE-300MIN (>= 300 minutes/week); ACTIVE-150MIN (>= 150 minutes), INACTIVE (no physical activity). Additionally, indicators of sedentary behavior were also assessed, as daily screen time (TV, videogames, and computer). The results from the questionnaire were compared with three 24-hour recalls. The results of ACTIVE-300MIN, ACTIVE-150MIN, and INACTIVE generated by PeNSE showed high accuracy. These indicators performed better than those of sedentary behavior in relation to frequency estimates as well as sensitivity, specificity, and correct classification rate. The indicators of physical activity from PeNSE showed satisfactory relative validity.