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Reliability of GENEActiv accelerometers to estimate sleep, physical activity, and sedentary time in children
Devan Antczak1, Chris Lonsdale1, Borja Del Pozo Cruz2
1Institute for Positive Psychology and Education, Australian Catholic University, PO Box 968, Level 10 33 Berry Street, New South Wales, 2060, North Sydney, Australia.
Insights
This study found that 3-5 nights of accelerometer data are needed for reliable sleep estimates in children. Similarly, 3-4 days of data ensure accurate physical activity and sedentary time measurements.
Area of Science:
- Pediatric Health Research
- Biomedical Data Analysis
- Sleep Science
Background:
- Accurate measurement of habitual sleep, physical activity, and sedentary time is crucial for understanding their health impacts.
- While criteria for physical activity and sedentary time are established, reliable sleep estimation methods require further definition.
- This study addresses the uncertainty surrounding the required duration of accelerometer wear for accurate sleep behavior assessment.
Purpose of the Study:
- To determine the minimum number of nights required for reliable estimation of habitual sleep behavior in children using wrist-worn accelerometers.
- To examine the number of days needed to obtain reliable estimates of physical activity and sedentary time in the same cohort.
Main Methods:
- Utilized data from a two-year longitudinal study involving 2,745 children (ages 7-12).
- Children wore GENEActiv accelerometers 24 hours/day for up to 8 days across three timepoints.
- Calculated reliability for sleep parameters (duration, efficiency, onset, wake time, time in bed) and physical activity/sedentary time metrics using intraclass correlations and the Spearman Brown prophecy formula.
Main Results:
- Achieving acceptable reliability (ICC ≥ 0.7) for sleep outcomes required 3 to 5 nights of accelerometer data.
- Reliable estimates for physical activity and sedentary time outcomes were obtained with 3 to 4 days of data.
- The findings provide specific duration criteria for accelerometer-based behavioral assessments in children.
Conclusions:
- Researchers should incorporate these minimum wear-time criteria (3-5 nights for sleep, 3-4 days for activity/sedentary time) when designing studies.
- Ensuring sufficient wear-time compliance is essential for obtaining valid and reliable data on children's behaviors.
- These guidelines support more accurate investigations into the links between sleep, physical activity, sedentary time, and health outcomes in pediatric populations.
Background:
Reliable estimates of habitual sleep, physical activity, and sedentary time are essential to investigate the associations between these behaviours and health outcomes. While the number of days needed and hours/day for estimates of physical activity and sedentary time are generally known, the criteria for sleep estimates are more uncertain. The objective of this study was to identify the number of nights needed to obtain reliable estimates of habitual sleep behaviour using the GENEActiv wrist worn accelerometer. The number of days to obtain reliable estimate of physical activity was also examined.
Methods:
Data was used from a two-year longitudinal study. Children wore an accelerometer for up to 8 days 24 h/day across three timepoints. The sample included 2,745 children (51 % girls) between the ages of 7-12-years-old (mean = 9.8 years, SD = 1.1 year) with valid accelerometer data from any timepoint. Reliability estimates were calculated for sleep duration, sleep efficiency, sleep onset, wake time, time in bed, light physical activity, moderate physical activity, moderate-to-vigorous physical activity, vigorous physical activity, and sedentary time.
Results:
Intraclass correlations and the Spearman Brown prophecy formula were used to determine the nights and days needed for reliable estimates. We found that between 3 and 5 nights were needed to achieve acceptable reliability (ICC = 0.7) in sleep outcomes, while physical activity and sedentary time outcomes required between 3 and 4 days.
Conclusions:
To obtain reliable estimates, researchers should consider these minimum criteria when designing their studies and prepare strategies to ensure sufficient wear time compliance.
