Adolescents' next-day perceptions of their sleep quality, quantity, sleepiness and sleepiness-related symptoms relative to actigraphy metrics.

BACKGROUND

Next-day perceptions of sleep and related symptoms are frequently collected in research and clinical practice, but how they correlate with objective sleep measures in adolescents has received little attention.

METHODS

Participants were aged 16-17 years and without a sleep disorder, anxiety or depression diagnosis. Seven-day wrist actigraphy was collected alongside daily survey ratings of sleep quality, sufficiency, morning and daytime sleepiness, and sleepiness-related mood and concentration. Within-person associations between daily actigraphic sleep metrics (6 variables representing quantity, quality and timing) and subjective ratings were estimated using mixed effects regression models with participant included as a random effect.

RESULTS

The sample comprised 71 adolescents (49 % female, 51 % male). No actigraphy metrics linked to sleep sufficiency ratings. Sleep onset was the strongest correlate of sleep quality and morning sleepiness in the expected direction e.g. every 10 min later onset led to a -1.4 point (95 % CI: -2.1, -0.7) drop in the sleep quality score (5-point scale, higher worse), but significant relationships were only in females. While actigraphic sleep quantity metrics were linked to several ratings, all effect sizes were marginal. Sleep quality metrics in the overall sample were not correlated to any ratings. Unexpectedly, timing and quantity metrics linked to sleepiness-related mood ratings, but in the opposite direction hypothesized.

CONCLUSIONS

The lack of correlation between objective and subjective sleep quality add to the complexity of defining sleep quality accurately. Sleep onset timing, rarely explored in these types of studies emerged as an important correlate of sleep quality perception and other subjective ratings.