title: Comparison of Physical Activity Adult Questionnaire results with accelerometer data.
abstract: BACKGROUND
  Discrepancies between self-reported and objectively measured physical activity are well-known. For the purpose of validation, this study compares a new self-reported physical activity questionnaire with an existing one and with accelerometer data.
  
  
  METHODS
  Data collected at one site of the Canadian Health Measures Survey in 2013 were used for this validation study. The International Physical Activity Questionnaire (IPAQ) was administered to respondents during the household interview, and the new Physical Activity for Adults Questionnaire (PAAQ) was administered during a subsequent visit to a mobile examination centre (MEC). At the MEC, respondents were given an accelerometer to wear for seven days. The analysis pertains to 112 respondents aged 18 to 79 who wore the accelerometer for 10 or more hours on at least four days.
  
  
  RESULTS
  Moderate-to-vigorous physical activity (MVPA) measured by accelerometer had higher correlation with data from the PAAQ (r = 0.44) than with data from the IPAQ (r = 0.20). The differences between accelerometer and PAAQ data were greater based on accelerometer-measured physical activity accumulated in 10-minute bouts (30-minute difference in MVPA) than on all minutes (9-minute difference). The percentages of respondents meeting the Canadian Physical Activity Guidelines were 90% based on self-reported IPAQ minutes, 70% based on all accelerometer MVPA minutes, 29% based on accelerometer MVPA minutes accumulated in 10-minute bouts, and 61% based on self-reported PAAQ minutes.
  
  
  CONCLUSIONS
  The PAAQ demonstrated reasonable validity against the accelerometer criterion. Based on correlations and absolute differences between daily minutes of MVPA and the percentages of respondents meeting the Canadian Physical Activity Guidelines, PAAQ results were closer to accelerometer data than were the IPAQ results for the study sample and previous Statistics Canada self-reported questionnaire findings.
authors.affiliation: Health Analysis Division, Statistics Canada, Ottawa, Ontario.
authors.forename: Didier
authors.initials: D
authors.lastname: Garriguet
authors.affiliation: Special Surveys Division, Statistics Canada, Ottawa, Ontario.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Tremblay
authors.forename: Rachel C
authors.initials: RC
authors.lastname: Colley
mesh_terms: D061725:Accelerometry / Q000592:standards*; D000293:Adolescent; D000328:Adult; D000368:Aged; D002170:Canada; D015444:Exercise; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D057566:Self Report / Q000592:standards*; D011795:Surveys and Questionnaires / Q000592:standards*; D055815:Young Adult
keywords: Data collection; direct measure; misclassification; motor activity; movement