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Comparison of objectively measured and self-reported time spent sitting
J Lagersted-Olsen1, M Korshøj1, J Skotte1
1National Research Centre for the Working Environment, Copenhagen, Denmark.
International Journal of Sports Medicine
|November 22, 2013
Summary
Objective measures are recommended for accurately quantifying sitting time, as self-reports significantly underestimate total sitting time and overestimate uninterrupted sitting time, showing poor agreement.
Area of Science:
- Occupational Health
- Behavioral Science
- Biomedical Engineering
Background:
- Objective quantification of sitting time has been limited.
- Accurate measurement of sedentary behavior is crucial for health research.
Purpose of the Study:
- To validate self-reported sitting time against objective measurements.
- To assess agreement between subjective and objective measures of total and uninterrupted sitting time.
Main Methods:
- 26 office workers wore accelerometers (ActiGraph GT3X+) for 7 days.
- Customized software (Acti4) identified sitting time from accelerometer data.
- Self-reported sitting time was collected via a 7-day questionnaire.
Main Results:
- No significant correlations were found between objective and self-reported sitting time (r<0.315).
- Self-reports significantly underestimated total sitting time on leisure days (2.4h) and overestimated uninterrupted sitting time (0.4-0.5h).
- Bland-Altman plots revealed poor agreement and wide limits of agreement between methods.
Conclusions:
- There is a significant lack of agreement between self-reported and objectively measured sitting time.
- Individual variation in sitting time is substantial.
- Objective measurement methods are recommended for accurate sitting time assessment.
