title: Validity and reliability of a modified english version of the physical activity questionnaire for adolescents.
abstract: BACKGROUND
  Adaptation of physical activity self-report questionnaires is sometimes required to reflect the activity behaviours of diverse populations. The processes used to modify self-report questionnaires though are typically underreported. This two-phased study used a formative approach to investigate the validity and reliability of the Physical Activity Questionnaire for Adolescents (PAQ-A) in English youth. Phase one examined test content and response process validity and subsequently informed a modified version of the PAQ-A. Phase two assessed the validity and reliability of the modified PAQ-A.
  
  
  METHODS
  In phase one, focus groups (n = 5) were conducted with adolescents (n = 20) to investigate test content and response processes of the original PAQ-A. Based on evidence gathered in phase one, a modified version of the questionnaire was administered to participants (n = 169, 14.5 ± 1.7 years) in phase two. Internal consistency and test-retest reliability were assessed using Cronbach's alpha and intra-class correlations, respectively. Spearman correlations were used to assess associations between modified PAQ-A scores and accelerometer-derived physical activity, self-reported fitness and physical activity self-efficacy.
  
  
  RESULTS
  Phase one revealed that the original PAQ-A was unrepresentative for English youth and that item comprehension varied. Contextual and population/cultural-specific modifications were made to the PAQ-A for use in the subsequent phase. In phase two, modified PAQ-A scores had acceptable internal consistency (α = 0.72) and test-retest reliability (ICC = 0.78). Modified PAQ-A scores were significantly associated with objectively assessed moderate-to-vigorous physical activity (r = 0.39), total physical activity (r = 0.42), self-reported fitness (r = 0.35), and physical activity self-efficacy (r = 0.32) (p ≤ 0.01).
  
  
  CONCLUSIONS
  The modified PAQ-A had acceptable internal consistency and test-retest reliability. Modified PAQ-A scores displayed weak-to-moderate correlations with objectively measured physical activity, self-reported fitness, and self-efficacy providing evidence of satisfactory criterion and construct validity, respectively. Further testing with more diverse English samples is recommended to provide a more complete assessment of the tool.
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, WC1E6BT UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Aggio
authors.affiliation: Department of Sport and Physical Activity, Edge Hill University, St. Helens Road, Ormskirk, Lancashire L39 4QP UK ; Department of Physical Education and Sport Sciences, University of Limerick, Limerick, Ireland.
authors.forename: Stuart
authors.initials: S
authors.lastname: Fairclough
authors.affiliation: Physical Activity Exchange, Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, 62 Great Crosshall Street, Liverpool, L3 2AT UK.
authors.forename: Zoe
authors.initials: Z
authors.lastname: Knowles
authors.affiliation: Physical Activity Exchange, Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, 62 Great Crosshall Street, Liverpool, L3 2AT UK.
authors.forename: Lee
authors.initials: L
authors.lastname: Graves
keywords: Accelerometry; Physical activity; Questionnaires; Self-report; Validity; Youth