Inconsistent sleep schedules and daytime behavioral difficulties in school-aged children

Abstract

Objectives

Current recommendations for healthy sleep in school-aged children are predominantly focused on optimal sleep duration (9–11 h). However, given the importance of routine for circadian health, the stability of sleep/wake schedules may also be important, especially for daytime behavioral functioning. We examined the relationship between short sleep duration, sleep schedule instability and behavioral difficulties in a community sample of Australian children.

Methods

Children, aged 5–10 years (N = 1622), without chronic health or psychological conditions, were recruited from primary schools in Adelaide, South Australia. A parent-report questionnaire was used to assess sleep/wake behavior. Behavioral functioning was assessed using the Strengths and Difficulties Questionnaire.

Results

Most children met sleep duration recommendations with approximately 5% reporting <9 h and 3% >12 h. Weekly variability of bed and rise times >1 h were reported in up to 50% of children. Multinomial regression analysis revealed sleep duration <10 h, bedtime latency >60 min, and bed and rise time variability >60 min significantly increased the risk of scoring in the 95th percentile for behavioral sub-scales.

Conclusions

Inconsistent sleep schedules were common and, similar to short sleep duration, were associated with behavioral difficulties. Considering the lack of study in this area, further research is needed for the development of new recommendations, education and sleep health messages.

Introduction

It is currently recommended that children aged 5–10 years obtain a minimum of 9–10 h sleep per night to maintain alertness and perform well during the day [1]. There is good evidence to demonstrate that children who sleep less than this recommended amount have deficits in school performance, cognitive and, most consistently, behavioral functioning [2], [3], [4]. Studies have shown that school-aged children who sleep <9 h, predominantly due to bed times later than 10 pm, are reported to be more emotionally labile [5], have higher aggressive and delinquent behaviors [6], and exhibit behaviors similar to those observed in Attention Deficit/Hyperactivity Disorder (ADHD) [4].

While the primary focus of previous investigation in this area has been on sleep duration, a second but less understood sleep-related contributor to daytime functioning may be sleep schedule stability. Sleep schedule refers to the timing of bed- and rise time, and consequently sleep duration. Changes in sleep scheduling between school and non-school nights and the associations with daytime performance have been well studied, particularly in adolescents [7], however, studies examining nightly changes in bed and sleep times are scarce and somewhat inconsistent. Bates et al. [8] reported that a regular sleep schedule in preschool children, defined as the variance in bed and sleep time over a four-week period, was associated with better adjustment and overall behavior in school. Fuligni and Hardway [9] reported that a poor sleep schedule in adolescents, defined as average daily deviation from the subject’s own mean over a two week period, was associated with increased anxiety and depression. In contrast, Pesonen et al. [10] did not find a significant relationship between inconsistent bedtimes, rise times or sleep duration and behavioral problems in a cohort of 8-year-old children. However, similar to previous findings in adolescents [11], these authors did report a behavioral association with increased irregularity in sleep duration between week and weekend nights. Thus, these findings suggest that maintaining a consistent sleep-wake pattern is important for optimal daytime functioning, yet, perhaps due to the dearth of research, it is often overlooked when discussing healthy sleep in children.

Therefore, the aims of this study were to address this research gap and add to current knowledge by examining sleep/wake patterns and daytime behavior in a large cohort of community children to determine the specific associations between sleep duration, regularity of sleep schedules, and behavioral functioning. It is predicted that short sleep durations and inconsistent sleep schedules would be associated with increased behavioral difficulties.