title: School Start Time and Adolescent Sleep Patterns: Results From the U.S. National Comorbidity Survey--Adolescent Supplement.
abstract: OBJECTIVE
  We estimated associations between school start time and adolescent weeknight bedtime, weeknight sleep duration, and weekend compensatory sleep and assessed whether associations differ by age, sex, or urbanicity.
  
  
  METHODS
  We used a subsample of a nationally representative, cross-sectional survey of 7308 students aged 13 to 18 years attending 245 schools to estimate associations of school start time, reported by school principals, with weeknight bedtime and sleep duration and weekend compensatory sleep, reported during adolescent face-to-face interviews.
  
  
  RESULTS
  Start time was positively associated with weeknight bedtime. Associations between start time and weeknight sleep duration were nonlinear and were strongest for start times of 8:00 am and earlier. Associations differed by sex and urbanicity, with the strongest association among boys in major metropolitan counties. Start time was negatively associated with sleep duration among boys in nonurban counties. Start time was not associated with weekend compensatory sleep.
  
  
  CONCLUSIONS
  Positive overall associations between school start time and adolescent sleep duration at the national level support recent policy recommendations for delaying school start times. However, the impact of start time delays may differ by sex and urbanicity.
authors.affiliation: Diana Paksarian, Jian-Ping He, and Kathleen R. Merikangas are with the Genetic Epidemiology Research Branch, National Institute of Mental Health, Bethesda, MD. Kara E. Rudolph is with the School of Public Health, University of California, Berkeley, and Center for Health and Community, University of California, San Francisco.
authors.forename: Diana
authors.initials: D
authors.lastname: Paksarian
authors.forename: Kara E
authors.initials: KE
authors.lastname: Rudolph
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: He
authors.forename: Kathleen R
authors.initials: KR
authors.lastname: Merikangas
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001071:Appointments and Schedules; D015897:Comorbidity; D003430:Cross-Sectional Studies; D020920:Dyssomnias / Q000453:epidemiology / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D012574:Schools / Q000458:organization & administration* / Q000706:statistics & numerical data; D012737:Sex Factors; D012890:Sleep; D013997:Time Factors; D014481:United States; D014505:Urban Population / Q000706:statistics & numerical data