Reliability and validity of a school-based physical activity questionnaire.

Purpose: To determine the reliability and validity of the School Health Action, Planning and Evaluation System (SHAPES) physical activity questionnaire, a machine-readable questionnaire designed to collect data from all students in a school from grades 6 to 12 and to provide feedback to the school for planning and evaluation.

Methods: Study 1 assessed test-retest reliability by administering the questionnaire twice, 1 wk apart to 2812 students in grades 9-12. Study 2 assessed criterion validity using MTI accelerometers worn consecutively for 7 d, and measured height and weight (N = 67, grades 6-12).

Results: The overall kappa/weighted kappa coefficient for the 1-wk test-retest reliability of the questionnaire items indicated moderate agreement (mean 0.57 +/- 0.24). Self-reported and accelerometer-measured average daily time spent performing moderate to vigorous physical activity were significantly correlated (Spearman r = 0.44, P < 0.01); however, students tended to overreport physical activity. Height and weight were not consistently over- or underreported. Self-reported and measured body mass index were significantly correlated (Spearman r = 0.90, P < 0.001). Classification of weight status by body mass index was similar using self-reported values compared with measured values.

Conclusion: The findings of these studies suggest that the SHAPES physical activity questionnaire has acceptable reliability and validity and is suitable for use in large-scale school-based data collections for child and adolescent populations.