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Comparing GPS, Log, Survey, and Accelerometry to Measure Physical Activity
Peter James1, Jennifer Weissman2, Jean Wolf3
1Harvard TH Chan School of Public Health, Department of Epidemiology, Boston, MA, USA. pjames@hsph.harvard.edu.
American Journal of Health Behavior
|December 22, 2015
Summary
Travel logs and questionnaires offer a cost-effective way to measure physical activity (PA) and travel duration, showing good agreement with objective GPS and accelerometer data, though with some limitations for light and moderate PA.
Area of Science:
- Physical activity research
- Objective and subjective measurement in health studies
- Travel behavior analysis
Background:
- Objective measures like GPS and accelerometry are valuable for assessing physical activity (PA) and travel.
- However, their cost and technical requirements limit large-scale population studies.
- Alternative methods like travel logs and questionnaires are more feasible but require validation.
Purpose of the Study:
- To compare the accuracy of travel logs and questionnaires against objective GPS and accelerometer data.
- To evaluate the prediction of trip duration and physical activity (PA) using these different methods.
- To inform the development of more effective tools for population-level health research.
Main Methods:
- 99 participants wore GPS devices and accelerometers for 5 consecutive days.
- Participants maintained detailed travel logs and completed questionnaires on PA and travel behaviors.
- Data from objective devices were compared with self-reported log and questionnaire data.
Main Results:
- Good agreement was found between GPS and log data for trip duration assessment.
- Log measures tended to overestimate trip duration compared to GPS.
- Log measures underestimated light PA and overestimated moderate PA compared to accelerometry.
Conclusions:
- Travel logs and questionnaires are cost-effective alternatives to GPS and accelerometry for population research.
- These subjective methods demonstrate reasonable concordance with objective measures for trip duration.
- Further development is needed to improve the accuracy of questionnaires and logs in assessing light and moderate physical activity.
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