Validation of Actigraphy in Middle Childhood
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Published on: July 27, 2022
Lisa J Meltzer1, Petrina Wong2, Sarah N Biggs3
1Department of Pediatrics, National Jewish Health, Denver, CO.
Insights
Actigraphy accurately detects sleep in children but struggles to identify wakefulness, especially in those with periodic limb movements in sleep. This study validates actigraphy for school-aged children, noting limitations in sleep onset latency measurement.
Area of Science:
- Pediatric Sleep Medicine
- Biomedical Engineering
- Clinical Validity Studies
Background:
- Limited research exists on the accuracy of actigraphy in school-aged children.
- Actigraphy is a non-invasive method for sleep monitoring, often used as an alternative to polysomnography (PSG).
- Understanding actigraphy's validity is crucial for its application in pediatric sleep research and clinical practice.
Purpose of the Study:
- To evaluate the validity of a specific actigraph (Philips Respironics Actiwatch-2) against polysomnography (PSG) in children aged 5-12 years born prematurely.
- To assess actigraphy's accuracy in measuring sleep onset latency, total sleep time (TST), and sleep efficiency in a natural home environment.
Main Methods:
- 148 preterm children (ages 5-12) simultaneously underwent ambulatory PSG and wore an Actiwatch-2 for one night.
- Sleep parameters including sleep onset latency, TST, and sleep efficiency were compared between actigraphy and PSG.
- Sensitivity, specificity, and accuracy were calculated; secondary analyses explored differences based on sleep disorders like obstructive sleep apnea syndrome and periodic limb movements in sleep (PLMS).
Main Results:
- Actigraphy underestimated total sleep time by approximately 30 minutes and sleep efficiency by 5%.
- Sleep onset latency was inaccurately estimated by at least 10 minutes for one-third of the children.
- While sensitivity (0.88) and accuracy (0.84) were good, specificity was notably lower (0.46). Discrepancies were larger in children with PLMS.
Conclusions:
- Actigraphy demonstrates good sensitivity for detecting sleep but poor specificity for detecting wakefulness in school-aged children.
- The accuracy of actigraphy is influenced by conditions like PLMS, impacting measurements of total sleep time and sleep efficiency.
- Careful interpretation of actigraphy data is necessary, particularly concerning sleep onset latency and in children with specific sleep disorders.
Study Objectives:
Few studies have examined the validity of actigraphy in school-aged children. The objective of this study was to examine the validity of a commonly used actigraph compared to polysomnography (PSG) in a sample of children age 5 to 12 y born prematurely, sleeping in their natural home environment.
Methods:
148 children born preterm (85 boys and 63 girls), ages 5-12 y (mean = 9.3 y, standard deviation = 2.0) wore the Philips Respironics Actiwatch-2 for 1 night concurrently with comprehensive, ambulatory PSG in the child's home. Sleep outcome variables were sleep onset latency, total sleep time (TST), and sleep efficiency. Epoch-by-epoch comparisons were used to determine sensitivity, specificity, and accuracy. Secondary analyses examined differences between children with no sleep issues, obstructive sleep apnea syndrome, and periodic limb movements in sleep (PLMS).
Results:
Actigraphy significantly underestimated TST (30 min) and sleep efficiency (5%). Actigraphy underestimated or overestimated sleep onset latency by at least 10 min for a third of the children. Sensitivity and accuracy were good at 0.88 and 0.84, respectively, whereas specificity was lower at 0.46. Differences between actigraphy and PSG for TST and sleep efficiency were greatest for children with PLMS.
Conclusions:
This study adds to the small existing literature demonstrating the validity of actigraphy in middle childhood. Although actigraphy shows good sensitivity (ability to detect sleep), specificity (ability to detect wake) is poor in this age group. Further, the results highlight the importance of considering whether a child has PLMS when interpreting actigraphic data, as well as the difficulties in accurately capturing sleep onset latency with actigraphy.
