title: How Many Sleep Diary Entries Are Needed to Reliably Estimate Adolescent Sleep?
abstract: To investigate (1) how many nights of sleep diary entries are required for reliable estimates of five sleep-related outcomes (bedtime, wake time, sleep onset latency [SOL], sleep duration, and wake after sleep onset [WASO]) and (2) the test-retest reliability of sleep diary estimates of school night sleep across 12 weeks.
  
  
  
  Data were drawn from four adolescent samples (Australia [n = 385], Qatar [n = 245], United Kingdom [n = 770], and United States [n = 366]), who provided 1766 eligible sleep diary weeks for reliability analyses. We performed reliability analyses for each cohort using complete data (7 days), one to five school nights, and one to two weekend nights. We also performed test-retest reliability analyses on 12-week sleep diary data available from a subgroup of 55 US adolescents.
  
  
  
  Intraclass correlation coefficients for bedtime, SOL, and sleep duration indicated good-to-excellent reliability from five weekday nights of sleep diary entries across all adolescent cohorts. Four school nights was sufficient for wake times in the Australian and UK samples, but not the US or Qatari samples. Only Australian adolescents showed good reliability for two weekend nights of bedtime reports; estimates of SOL were adequate for UK adolescents based on two weekend nights. WASO was not reliably estimated using 1 week of sleep diaries. We observed excellent test-rest reliability across 12 weeks of sleep diary data in a subsample of US adolescents.
  
  
  
  We recommend at least five weekday nights of sleep dairy entries to be made when studying adolescent bedtimes, SOL, and sleep duration. Adolescent sleep patterns were stable across 12 consecutive school weeks.
authors.affiliation: Zayed University, College of Natural and Health Sciences, Department of Psychology, Abu Dhabi, United Arab Emirates.|School of Psychology, Flinders University, Bedford Park, South Australia, Australia.
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Short
authors.affiliation: Department of Psychology, College of Natural and Health Sciences, Zayed University, Abu Dhabi, United Arab Emirates.|Department of Medicine, Weill Cornell Medicine, Doha, Qatar.|Department of Medicine, Weill Cornell Medicine, New York, NY.
authors.forename: Teresa
authors.initials: T
authors.lastname: Arora
authors.affiliation: School of Psychology, Flinders University, Bedford Park, South Australia, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Gradisar
authors.affiliation: Department of Medicine, Weill Cornell Medicine, Doha, Qatar.|Department of Medicine, Weill Cornell Medicine, New York, NY.|Department of Medicine, King's College London, London, UK.
authors.forename: Shahrad
authors.initials: S
authors.lastname: Taheri
authors.affiliation: Zayed University, College of Natural and Health Sciences, Department of Psychology, Abu Dhabi, United Arab Emirates.|E.P. Bradley Hospital Sleep Research Laboratory, Providence, RI.
authors.forename: Mary A
authors.initials: MA
authors.lastname: Carskadon
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D001315:Australia / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D011780:Qatar / Q000453:epidemiology; D015203:Reproducibility of Results; D012574:Schools; D057566:Self Report / Q000592:standards* / Q000706:statistics & numerical data*; D012890:Sleep / Q000502:physiology*; D013997:Time Factors; D006113:United Kingdom / Q000453:epidemiology; D014481:United States / Q000453:epidemiology; D014851:Wakefulness / Q000502:physiology
keywords: adolescent; reliability; sleep; sleep diary; test–retest.