title: Measuring activity in children and adolescents using self-report: PAQ-C and PAQ-A.
abstract: OBJECTIVE
  This study examined the psychometric properties of two versions of a commonly used physical activity 7-d self-report, the Physical Activity Questionnaire for Older Children (PAQ-C) and Physical Activity Questionnaire for Adolescents (PAQ-A).
  
  
  METHODS
  We longitudinally examined the internal consistency, stability, and situational effects of the PAQ-C and PAQ-A in a cohort of children (N = 210) at ages 11 and 13 yr. Statistical analysis included factor loading and standardized Cronbach coefficient alphas. We cross-sectionally examined concurrent validity of the PAQ-A in a subsample of our cohort (N = 49) at age 13 by comparing it with concurrently measured physical activity using an activity monitor (Actigraph). Spearman correlation coefficients were used for this analysis.
  
  
  RESULTS
  Standardized Cronbach alphas ranged from 0.72 to 0.88. A subsample analysis suggested that completing the questionnaires during the summer months slightly reduced the standardized alpha for the PAQ-C, but not the PAQ-A. Associations between the PAQ-A (revised) summary score and activity monitor variables were rho = 0.56 for total PA and rho = 0.63 for moderate through vigorous activity (P < 0.05). Associations between individual PAQ-A questions and activity monitor variables for the same time frame ranged from rho = 0.41 to 0.62 (P < 0.05).
  
  
  CONCLUSIONS
  The PAQ-C and PAQ-A show good internal consistency. The PAQ-A has acceptable validity.
authors.affiliation: Department of Health and Sports Studies, University of Iowa, Iowa City, IA 52242, USA. kathleen-janz@uiowa.edu
authors.forename: Kathleen F
authors.initials: KF
authors.lastname: Janz
authors.forename: Elena M
authors.initials: EM
authors.lastname: Lutuchy
authors.forename: Phyllis
authors.initials: P
authors.lastname: Wenthe
authors.forename: Steven M
authors.initials: SM
authors.lastname: Levy
mesh_terms: D000054:Acceleration; D000293:Adolescent; D000367:Age Factors; D002648:Child; D015444:Exercise / Q000502:physiology*; D005163:Factor Analysis, Statistical; D005260:Female; D015438:Health Behavior; D006306:Health Surveys; D006801:Humans; D008297:Male; D011939:Mental Recall; D009043:Motor Activity; D011594:Psychometrics; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires