title: The Relationship between Chronotype and Sleep Quality in Korean Firefighters.
abstract: OBJECTIVE
  We examined the relationship between chronotype and sleep disturbance, and assessed various factors that might be associated with sleep disturbance in Korean firefighters.
  
  
  METHODS
  Self-administered questionnaires assessing chronotype, depression, alcohol use, posttraumatic stress disorder (PTSD), stress response and sleep quality were examined in 515 firefighters.
  
  
  RESULTS
  Evening type firefighters more reported depression, alcohol use, PTSD, stress response and sleep disturbance. Also evening chronotype was the most significant risk factor for poor sleep quality (odds ratio [OR], 4.812; 95% confidence interval [CI], 2.448-9.459), even after controlling for all other variables (OR, 3.996; 95% CI, 1.806-8.841).
  
  
  CONCLUSIONS
  Chronotype was the factor most strongly associated with sleep disturbance, and therefore should be considered an important variable in sleep quality, particularly in occupations involving stressful activities, such as firefighting.
authors.affiliation: Department of Neuropsychiatry, Eulji University Hospital, Eulji University School of Medicine, Daejeon, Korea.
authors.forename: Ji-Ae
authors.initials: JA
authors.lastname: Yun
authors.affiliation: Department of Occupational and Environmental Medicine, Dongguk University Ilsan Hospital, Goyang, Korea.
authors.forename: Yeon-Soon
authors.initials: YS
authors.lastname: Ahn
authors.affiliation: Department of Occupational and Environmental Medicine, Dongguk University Ilsan Hospital, Goyang, Korea.
authors.forename: Kyoung-Sook
authors.initials: KS
authors.lastname: Jeong
authors.affiliation: Department of Neuropsychiatry, Eulji General Hospital, Eulji University School of Medicine, Seoul, Korea.
authors.forename: Eun-Jeong
authors.initials: EJ
authors.lastname: Joo
authors.affiliation: Department of Neuropsychiatry, Eulji University Hospital, Eulji University School of Medicine, Daejeon, Korea.
authors.forename: Kyeong-Sook
authors.initials: KS
authors.lastname: Choi
keywords: Chronotype; Insomnia; Sleep disturbance; firefighter