D: Reliability and Validity of Physical Activity Questionnaires for Children: The Children's Leisure Activities Study Survey (CLASS). Pediatric exercise science 2004

This study aimed to develop a reliable, valid, and feasible method for assess-ing physical activity among children ages 5–6 and 10–12 years. Test–retest reliability of a parental proxy questionnaire and a children’s self-report ques-tionnaire was assessed in 280 children and parents. The criterion validity of the questionnaires was assessed using accelerometry. The proxy questionnaire provided a reliable measure of the type, frequency, and duration of children’s physical activity. Neither version of the questionnaire provided an accurate estimate of individual children’s physical activity. To assess the type, frequency, intensity, and duration of children’s activity, a combination of questionnaire and objective measures should be employed. Physical activity is important for health, and promoting physical activity is an important component of national health strategies in developed and developing countries (5,23). Despite the fact that it is recognized as an important public health issue, only poor population-level data regarding children’s physical activity are available in Australia. This lack of population data relates, in part, to the universa