The discrepancy between actigraphic and sleep diary measures of sleep in adolescents.
Level 3 - non-randomized controlled study
Cross-sectional comparative validation study without a gold-standard reference test
PubMed 22437142 · doi:10.1016/j.sleep.2011.11.005
What was done
Researchers evaluated discrepancies between wrist actigraphy, an 8-day sleep diary, and parent reports in 385 South Australian adolescents aged 13 to 18 years (mean age 15.6, SD 0.95; 60% male) recruited from eight high schools. Participants completed daytime sleepiness and fatigue surveys alongside an 8-day concurrent sleep diary and wrist actigraphy protocol, while parents completed a medical and sleep history survey.
What was found
Actigraphic estimates of wake after sleep onset (WASO) were substantially higher than sleep diary estimates (74 minutes vs. 7 minutes). Total sleep time was substantially lower via actigraphy (6 hours 51 minutes) than sleep diary (8 hours 16 minutes) or parent report (8 hours 51 minutes). Actigraphy showed no significant relationship with daytime functioning measures and weak relationships with diary variables. Greater WASO and less sleep were scored in boys compared to girls, and in pubertally mature boys compared to less mature boys.
Why it matters
Actigraphy algorithms may misclassify normal adolescent nighttime motor activity as wakefulness, particularly in boys, leading to significant underestimations of sleep duration compared to subjective reports.
Limits
The study lacked polysomnography to definitively confirm whether the discrepancy stems from actigraphy error or subjective recall inaccuracy. The sample was drawn exclusively from one geographic region and was predominantly male.
Cited by
- supports Wrist-movement-based sleep tracking underestimates wake time compared to EEG brain wave measurements, but overestimates wake time compared to self-report.