title: Validity and reliability question 8 of the Paffenbarger Physical Activity Questionnaire among healthy adults.
abstract: BACKGROUND
  Little information exists regarding the psychometric properties of question 8 (Q8) of the Paffenbarger Physical Activity Questionnaire (PPAQ) to assess exercise. Thus, we conducted 2 studies to assess the validity and test-retest reliability of Q8 among adults.
  
  
  METHODS
  Study 1 participants (n = 419) were 44.1 ± 16.1 years of age. Validity was determined by comparing self-reported hr·d-1 in sedentary, light, moderate, and vigorous intensity physical activity (PA) and MET-hr·wk-1 on Q8 at baseline to accelerometer and health/fitness measurements using Spearman rank-order correlations. Study 2 participants (n = 217) were 44.7 ± 16.3 years of age and completed Q8 at baseline, 3 months, and 6 months. Test-retest reliability was determined using repeated measures analysis of covariance, intraclass correlations (ICCs), and standard error of the measurement (SEM).
  
  
  RESULTS
  Q8 displayed good criterion validity compared with accelerometer measurements (r = .102 to .200, P < .05) and predictive validity compared with health/fitness measurements (r = -.272 to .203, P < .05). No differences were observed in self-reported hr·d-1 in any of the PA categories at baseline, 3 months, and 6 months (ICC: 0.49 to 0.68; SEM: 1.0 to 2.0; P > .05), indicating good reliability.
  
  
  CONCLUSIONS
  Q8 demonstrates adequate criterion validity, acceptable predictive validity, and satisfactory test-retest reliability and can be used in conjunction with other components of the PPAQ to provide a complete representation of exercise.
authors.affiliation: Dept of Kinesiology, University of Connecticut, Storrs, CT.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Simpson
authors.forename: Beth
authors.initials: B
authors.lastname: Parker
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Capizzi
authors.forename: Paul
authors.initials: P
authors.lastname: Thompson
authors.forename: Priscilla
authors.initials: P
authors.lastname: Clarkson
authors.forename: Patty
authors.initials: P
authors.lastname: Freedson
authors.forename: Linda Shannon
authors.initials: LS
authors.lastname: Pescatello
mesh_terms: D061725:Accelerometry; D000328:Adult; D001823:Body Composition; D015444:Exercise; D005080:Exercise Test; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D010809:Physical Fitness; D011594:Psychometrics; D015203:Reproducibility of Results; D057566:Self Report; D011795:Surveys and Questionnaires