Abstract
Archived Content
Information identified as archived is provided for reference, research or recordkeeping purposes. It is not subject to the Government of Canada Web Standards and has not been altered or updated since it was archived. Please "contact us" to request a format other than those available.
Background
Keywords
Findings
Author
What is already known on this subject?
What does this study add?
Background
Systematic reviews and results of Statistics Canada surveys have shown a discrepancy between self-reported and measured physical activity. This study compares these two methods and examines specific activities to explain the limitations of each method.
Data and methods
Data are from cycle 1 (2007 to 2009) and cycle 2 (2009 to 2011) of the Canadian Health Measures Survey. The survey involved an interview in the respondent’s home and a visit to a mobile examination centre (MEC) for physical measurements. In a questionnaire, respondents were asked about 21 leisure-time physical activities. They were requested to wear an Actical accelerometer for seven days after the MEC visit. The analysis pertains to respondents aged 12 to 79 who wore the accelerometer for 10 or more hours on at least four days (n = 7,158).
Results
Averages of self-reported leisure-time physical activity and moderate-to-vigorous physical activity measured by accelerometer were within a couple of minutes of each other. However, at the individual level, the difference between estimates could exceed 37.5 minutes per day in one direction or the other, and around 40% of the population met physical activity thresholds according to one measurement method, but not according to the other. The disagreement is supported by weak observed correlations.
Interpretation
The lack of a systematic trend in the relationship between the two methods of measuring physical activity precludes the creation of correction factors or being confident in using one method instead of the other. Accelerometers and questionnaires measure different aspects of physical activity.
Keywords
Data collection, direct measure, misclassification, motor activity, movement
Findings
A large body of evidence supports an association between physical activity and health. This evidence was instrumental in revision of the Canadian Physical Activity Guidelines, published in 2011. [Full Text]
Author
Didier Garriguet (didier.garriguet@statcan.gc.ca) is with the Health Analysis Division at Statistics Canada, Ottawa, Ontario, K1A 0T6. Rachel C. Colley was formerly with the Children’s Hospital of Eastern Ontario Research Institute and the Health Analysis Division at Statistics Canada.
What is already known on this subject?
- According to self-reported data from the Canadian Community Health Survey, 53.9% of people were moderately active during their leisure time.
- Accelerometer-based data from the Canadian Health Measures Survey show that 15% of adults and fewer than 10% of adolescents met guidelines for moderate-to-vigorous physical activity.
- Results of systematic reviews of comparisons of these two methods of measuring physical activity have been inconclusive.
What does this study add?
- Averages of self-reported leisure-time physical activity and measured moderate-to-vigorous physical activity were within a couple of minutes of each other.
- However, at the individual level, the absolute difference between measured and self-reported physical activity could exceed 37.5 minutes per day.
- Misclassification of people as meeting the guidelines is 40%.
- Self-reported walking and gardening account for the discrepancy between the results of the measurement methods in the older age group.
- Date modified: