Which objective sleep elements predict children's perceptions of good sleep quality? A preliminary investigation based on polysomnography and actigraphy.

Objectives: Objective sleep elements that underlie child ratings of sleep quality are largely unknown. Child-based sleep recommendations, therefore, typically focus on duration. An expert panel recently provided specific recommendations regarding objective sleep parameters that correspond with higher quality sleep, but child-based studies from which to draw conclusions were notably limited. The present study used actigraphy and polysomnography to explore sleep continuity and architectural variables that correspond with higher ratings of sleep quality in a sample of school-aged children.

Methods: Fifty-two healthy, prepubertal children (aged 7-11 years) completed one night of unattended ambulatory polysomnography at home with concurrent actigraphy and provided sleep quality ratings the following morning. Associations between sleep variables and subjective ratings were examined using polynomial regression models to examine potential linear and nonlinear relationships.

Results: In contrast to findings among adults, total sleep time, sleep onset latency, and sleep efficiency values were unrelated to child ratings of sleep quality. Wake after sleep onset (WASO) showed a curvilinear (reversed j-shaped) relationship such that perceptions of sleep quality were high when WASO values were less than approximately 30 minutes. For sleep architecture, N1% showed a significant quadratic association with sleep quality such that N1% between 2% and 6% corresponded with high sleep quality ratings.

Conclusions: Our findings support expert recommendations regarding WASO values that predict high quality sleep in children, but also await replication. There is need for additional research aimed at understanding objective sleep elements and other influences of children's perceptions of sleep quality using linear and nonlinear models.