Longitudinal Outcomes of Start Time Delay on Sleep, Behavior, and Achievement in High School
Upper secondary Sleep and the body
Links to claims
Limits (1)
| Claim | Basis |
|---|---|
| C14 | One NY high school, 45-min later start: about 20 min more self-reported sleep at first, back to baseline a year later; absences rose about 5 days/year in the within-student analysis; course failures spiked in the transition year (6.04%); grades did not change in cohort-sequential analyses; Regents scores showed no consistent gain. C14 weakened 2026-10-17 (consistency bound). |
Review state: first-pass draft, pending human review.
Source note
Syntes: Longitudinal Outcomes of Start Time Delay on Sleep, Behavior, and Achievement in High School (2016)
Källa: https://doi.org/10.5665/sleep.5426 (Sleep 39(2), 271–281)
Verified content
- [abstract] One public high school in upstate New York delayed its start by 45 minutes; surveys at baseline (May 2012) and two follow-ups (November 2012, May 2013); school records 2010–2014.
- [abstract] Students reported 20 minutes longer sleep at the first follow-up; by the second follow-up bedtimes had moved later and total sleep was back at baseline.
- [abstract] Lasting improvements in tardiness and disciplinary violations; no changes in the other variables, including academic performance.
- [full text, PMC4712391] Start moved from 07:45 to 08:30 (Glens Falls, a walking district); 410 and 372 students in grades 9–12 completed the two follow-ups.
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[full text] Grades: cohort-sequential GPA analyses over 2010–2014 (two years before and two after) found no change tied to the start time; cross-sectional comparisons found no differences in grades 9, 10 and 12 and a small rise in grade 11. Regents exams: only 2011–2012 vs 2012–2013 were compared; 2 of 20 subject tests differed, both higher before the change.
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[full text] Absences rose after the delay in the within-student analysis: all-absence ratio 0.085 → 0.113 (~+5 days/year); same-student subset 12.8 → 17.7 days/year. Cross-sectional roster counts without repeated measures wrongly suggested a tiny decrease.
- [full text] Course-failure rate among students who experienced the change: 4.72%, 4.49%, 6.04% (transition year), 4.39%. Unexcused tardies 0.066 → 0.05. Proportion reporting ≥8 h sleep: 40% → 60% → 50%.
Limits
- [full text] Self-reported sleep (PSQI, not validated in adolescents, as the authors note).
- [assessment] One school, no comparison school; cohort comparisons are open to cohort effects.
Added 2026-10-17 by the project (nightly attack run). [abstract] = from the published abstract; [full text] = read in the full text; [assessment] = the project's own assessment.
Metadata as recorded
- ID
- SLEEP-012
- Tier
- pre/post (one school, cohort comparisons)
- Titel
- Longitudinal Outcomes of Start Time Delay on Sleep, Behavior, and Achievement in High School
- År
- 2016
- Källa/DOI
- https://doi.org/10.5665/sleep.5426
- Tidskrift
- Sleep 39(2), 271–281
- Typ
- peer-reviewed article
- Åldersgrupp
- gymnasium
- Teman
- somn-och-kropp
- Hämtad
- 2026-10-17
- Verifierad
- Crossref metadata (title, authors, journal, volume, pages) checked 2026-10-17
The original files (PDF or abstract) are kept in the project archive and are not published here.