title: Adverse Effects of Daylight Saving Time on Adolescents' Sleep and Vigilance.
abstract: OBJECTIVE
  Daylight saving time (DST) has been established with the intent to reduce energy expenditure, however unintentional effects on sleep and vigilance have not been consistently measured. The objective of this study was to test the hypothesis that DST adversely affects high school students' sleep and vigilance on the school days following its implementation.
  
  
  METHODS
  A natural experiment design was used to assess baseline and post-DST differences in objective and subjective measures of sleep and vigilance by actigraphy, sleep diary, sleepiness scale, and psychomotor vigilance testing (PVT). Students were tested during school days immediately preceding and following DST.
  
  
  RESULTS
  A total of 40 high school students were enrolled in this study; 35 completed the protocol. Sleep duration declined by an average of 32 minutes on the weeknights post-DST, reflecting a cumulative sleep loss of 2 h 42 min as compared to the baseline week (p = 0.001). This finding was confirmed by sleep diary analyses, reflecting an average sleep loss of 27 min/night (p = 0.004) post-DST. Vigilance significantly deteriorated, with a decline in PVT performance post-DST, resulting in longer reaction times (p < 0.001) and increased lapses (p < 0.001). Increased daytime sleepiness was also demonstrated (p < 0.001).
  
  
  CONCLUSIONS
  The early March DST onset adversely affected sleep and vigilance in high school students resulting in increased daytime sleepiness. Larger scale evaluations of sleep impairments related to DST are needed to further quantify this problem in the population. If confirmed, measures to attenuate sleep loss post-DST should be implemented.
authors.affiliation: Weill Cornell Medical College Center of Sleep Medicine, Cornell University, New York, NY.
authors.forename: Diana
authors.initials: D
authors.lastname: Medina
authors.affiliation: Weill Cornell Medical College Center of Sleep Medicine, Cornell University, New York, NY.
authors.forename: Matthew
authors.initials: M
authors.lastname: Ebben
authors.affiliation: Weill Cornell Medical College Center of Sleep Medicine, Cornell University, New York, NY.
authors.forename: Sara
authors.initials: S
authors.lastname: Milrad
authors.affiliation: Harvard University Health Careers Program, Boston, MA.
authors.forename: Brianna
authors.initials: B
authors.lastname: Atkinson
authors.affiliation: Weill Cornell Medical College Center of Sleep Medicine, Cornell University, New York, NY.
authors.forename: Ana C
authors.initials: AC
authors.lastname: Krieger
mesh_terms: D056044:Actigraphy; D000293:Adolescent; D000294:Adolescent Behavior / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D020178:Sleep Disorders, Circadian Rhythm / Q000503:physiopathology*
keywords: actigraphy; adolescent; daylight saving time; school; sleep; sleep deprivation; student; vigilance