title: Inconsistent sleep schedules and daytime behavioral difficulties in school-aged children.
abstract: OBJECTIVE
  Current recommendations for healthy sleep in school-aged children are predominantly focused on optimal sleep duration (9-11h). 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 <9h and 3% >12h. Weekly variability of bed and rise times >1h were reported in up to 50% of children. Multinomial regression analysis revealed sleep duration <10h, 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.
authors.affiliation: Childrens Research Centre, Discipline of Paediatrics, University of Adelaide, King William Road, Adelaide 5000, Australia. sarah.biggs@monash.edu
authors.forename: Sarah N
authors.initials: SN
authors.lastname: Biggs
authors.forename: Kurt
authors.initials: K
authors.lastname: Lushington
authors.forename: Cameron J
authors.initials: CJ
authors.lastname: van den Heuvel
authors.forename: A James
authors.initials: AJ
authors.lastname: Martin
authors.forename: J Declan
authors.initials: JD
authors.lastname: Kennedy
mesh_terms: D002648:Child; D002652:Child Behavior / Q000502:physiology* / Q000523:psychology; D002653:Child Behavior Disorders / Q000209:etiology* / Q000503:physiopathology* / Q000523:psychology; D002668:Child Rearing; D002675:Child, Preschool; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012890:Sleep / Q000502:physiology; D012892:Sleep Deprivation / Q000150:complications* / Q000503:physiopathology* / Q000523:psychology; D013021:South Australia; D011795:Surveys and Questionnaires / Q000592:standards; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology