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A quantitative bias analysis to estimate measurement error-related attenuation of the association between self-reported physical activity and colorectal cancer risk.
- Source :
- International Journal of Epidemiology; Feb2020, Vol. 49 Issue 1, p153-161, 9p
- Publication Year :
- 2020
-
Abstract
- <bold>Background: </bold>Self-reported physical activity is inaccurate, yet few investigators attempt to adjust for measurement error when estimating risks for health outcomes. We estimated what the association between self-reported physical activity and colorectal cancer risk would be if physical activity had been assessed using accelerometry instead.<bold>Methods: </bold>We conducted a validation study in which 235 Australian adults completed a telephone-administered International Physical Activity Questionnaire (IPAQ), and wore an accelerometer (Actigraph GT3X+) for 7 days. Using accelerometer-assessed physical activity as the criterion measure, we calculated validity coefficients and attenuation factors using a structural equation model adjusted for age, sex, education and body mass index. We then used a regression calibration approach to apply the attenuation factors to data from the Melbourne Collaborative Cohort Study (MCCS) to compute bias-adjusted hazard ratios (HR) and 95% confidence intervals (CI).<bold>Results: </bold>Average daily minutes of physical activity from the short form of the International Physical Activity Questionnaire (IPAQ-short) were substantially higher than accelerometer-measured duration (55 versus 32 min). The validity coefficient (0.32; 95% CI: 0.20, 0.43) and attenuation factor (0.20; 95% CI: 0.12, 0.28) were low. The HRs for colorectal cancer risk for high (75th percentile; 411 min/week) versus low (25th percentile; 62 min/week) levels of self-reported physical activity were 0.95 (95% CI: 0.87, 1.05) before and 0.78 (95% CI: 0.47, 1.28) after bias adjustment.<bold>Conclusions: </bold>Over-estimation of physical activity by the IPAQ-short substantially attenuates the association between physical activity and colorectal cancer risk, suggesting that the protective effect of physical activity has been previously underestimated. [ABSTRACT FROM AUTHOR]
- Subjects :
- PHYSICAL activity
COLORECTAL cancer
MEASUREMENT errors
STRUCTURAL equation modeling
QUANTITATIVE research
BODY mass index
COLON tumors
RESEARCH
RESEARCH evaluation
SELF-evaluation
RECTUM tumors
RESEARCH methodology
ACTIGRAPHY
EVALUATION research
MEDICAL cooperation
ACCELEROMETRY
SURVEYS
COMPARATIVE studies
EXERCISE
QUESTIONNAIRES
MOTOR ability
LONGITUDINAL method
STANDARDS
Subjects
Details
- Language :
- English
- ISSN :
- 03005771
- Volume :
- 49
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- International Journal of Epidemiology
- Publication Type :
- Academic Journal
- Accession number :
- 142579944
- Full Text :
- https://doi.org/10.1093/ije/dyz209