title: Sleep Duration and School Readiness of Chinese Preschool Children.
abstract: OBJECTIVE
  To examine the average sleep duration in Chinese preschoolers and to investigate the association between sleep duration and school readiness.
  
  
  METHODS
  This is a cross-sectional study that included 553 Chinese children (mean age = 5.46 years) from 20 preschools in 2 districts of Hong Kong. Average daily sleep duration in the last week was reported by parents and school readiness as measured by the teacher-rated Chinese Early Development Instrument (CEDI).
  
  
  RESULTS
  Most Chinese preschoolers had 9-10 hours of sleep per day. Only 11% of preschoolers had the recommended 11-12 hours of sleep per day. This group was associated with more "very ready" CEDI domains. Sleep deprivation (≤7 hours per day) was associated with a lower CEDI total score, lower scores in the emotional maturity and language/cognitive domain, and prosocial behaviors subdomain but a greater score in the hyperactivity/inattention subdomain. Children with a lower family socioeconomic index, lower maternal education level, infrequent parent-child interactions, and who used electronic devices for more than 3 hours per day had shortened sleep durations.
  
  
  CONCLUSIONS
  Optimal sleep duration was associated with better school readiness in preschool children, whereas sleep deprivation was associated with lower school readiness, more hyperactivity and inattention, and less prosocial behavior.
authors.affiliation: Department of Pediatrics and Adolescent Medicine, The University of Hong Kong, Hong Kong, China.
authors.forename: Winnie
authors.initials: W
authors.lastname: Tso
authors.affiliation: Faculty of Education, The University of Hong Kong, Hong Kong, China.
authors.forename: Nirmala
authors.initials: N
authors.lastname: Rao
authors.affiliation: Department of Paediatrics, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Jiang
authors.affiliation: Shanghai Children's Medical Center, Shanghai, China.
authors.forename: Albert Martin
authors.initials: AM
authors.lastname: Li
authors.affiliation: Department of Pediatrics and Adolescent Medicine, The University of Hong Kong, Hong Kong, China.
authors.forename: So-Lun
authors.initials: SL
authors.lastname: Lee
authors.affiliation: Department of Pediatrics and Adolescent Medicine, The University of Hong Kong, Hong Kong, China.
authors.forename: Frederick Ka-Wing
authors.initials: FK
authors.lastname: Ho
authors.affiliation: Department of Pediatrics and Adolescent Medicine, The University of Hong Kong, Hong Kong, China.
authors.forename: Sophia Ling
authors.initials: SL
authors.lastname: Li
authors.affiliation: Department of Pediatrics and Adolescent Medicine, The University of Hong Kong, Hong Kong, China. Electronic address: patricip@hku.hk.
authors.forename: Patrick
authors.initials: P
authors.lastname: Ip
mesh_terms: D044466:Asian People / Q000208:ethnology; D002648:Child; D002657:Child Development; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D007859:Learning Disabilities / Q000453:epidemiology*; D008297:Male; D010287:Parent-Child Relations; D012574:Schools; D012890:Sleep / Q000502:physiology*; D012892:Sleep Deprivation / Q000453:epidemiology*; D011795:Surveys and Questionnaires