title: The relationship between sleep and wake habits and academic performance in medical students: a cross-sectional study.
abstract: BACKGROUND
  The relationship between the sleep/wake habits and the academic performance of medical students is insufficiently addressed in the literature. This study aimed to assess the relationship between sleep habits and sleep duration with academic performance in medical students.
  
  
  METHODS
  This study was conducted between December 2009 and January 2010 at the College of Medicine, King Saud University, and included a systematic random sample of healthy medical students in the first (L1), second (L2) and third (L3) academic levels. A self-administered questionnaire was distributed to assess demographics, sleep/wake schedule, sleep habits, and sleep duration. Daytime sleepiness was evaluated using the Epworth Sleepiness Scale (ESS). School performance was stratified as "excellent" (GPA ≥ 3.75/5) or "average" (GPA <3.75/5).
  
  
  RESULTS
  The final analysis included 410 students (males: 67%). One hundred fifteen students (28%) had "excellent" performance, and 295 students (72%) had "average" performance. The "average" group had a higher ESS score and a higher percentage of students who felt sleepy during class. In contrast, the "excellent" group had an earlier bedtime and increased TST during weekdays. Subjective feeling of obtaining sufficient sleep and non-smoking were the only independent predictors of "excellent" performance.
  
  
  CONCLUSIONS
  Decreased nocturnal sleep time, late bedtimes during weekdays and weekends and increased daytime sleepiness are negatively associated with academic performance in medical students.
authors.affiliation: University Sleep Disorders Center, King Saud University, Box 225503, Riyadh 11324, Saudi Arabia. ashammam2@gmail.com
authors.forename: Ahmed S
authors.initials: AS
authors.lastname: Bahammam
authors.forename: Abdulrahman M
authors.initials: AM
authors.lastname: Alaseem
authors.forename: Abdulmajeed A
authors.initials: AA
authors.lastname: Alzakri
authors.forename: Aljohara S
authors.initials: AS
authors.lastname: Almeneessier
authors.forename: Munir M
authors.initials: MM
authors.lastname: Sharif
mesh_terms: D003430:Cross-Sectional Studies; D004522:Educational Status; D005260:Female; D006801:Humans; D008297:Male; D012890:Sleep; D013337:Students, Medical / Q000523:psychology / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires; D013997:Time Factors; D014851:Wakefulness; D055815:Young Adult