The discrepancy between actigraphic and sleep diary measures of sleep in adolescents.

OBJECTIVE: To explore the discrepancy between sleep diary and actigraphic measures of sleep in adolescents and to ascertain whether these discrepancies may vary according to characteristics of the participant.
METHODS: Participants were 385 adolescents aged 13-18years (X=15.6, standard deviation [SD]=0.95; 60% male) from eight high schools in South Australia. Adolescents completed the School Sleep Habits Survey and Pediatric Daytime Sleepiness Scale during class time, followed by an 8-day sleep diary and wrist actigraphy. The Flinders Fatigue Scale was completed on the final day of the study. Parents completed a sleep, medical, education, and family history survey.
RESULTS: Actigraphic estimates of wake after sleep onset (WASO) were substantially greater than sleep diary estimates (74min actigraphy vs. 7min sleep diary) and actigraphic estimates of total sleep time were substantially less than sleep diary and parent report (6h 51min actigraphy vs. 8h 16min sleep diary vs. 8h 51 parent report). Actigraphy displayed no significant relationship with daytime functioning and weak relationships with concomitantly recorded sleep diary variables. Sex and puberty-related differences in actigraphic scoring were found, with more WASO and less sleep scored in boys compared to girls and more WASO scored amongst pubertally-mature boys than boys of less advanced pubertal development.
CONCLUSIONS: There may be differences in the sleep of adolescents that result in less actigraphic total sleep scored than perceived, particularly in boys, possibly because of increased sleep motor activity in adolescents that actigraphic algorithms score as wake. This is a significant concern that requires further examination with polysomnography.