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Updated: Apr 5, 2026

Collecting Sleep, Circadian, Fatigue, and Performance Data in Complex Operational Environments
Published on: August 8, 2019
The Relationship between Chronotype and Sleep Quality in Korean Firefighters
Ji-Ae Yun1, Yeon-Soon Ahn2, Kyoung-Sook Jeong2
1Department of Neuropsychiatry, Eulji University Hospital, Eulji University School of Medicine, Daejeon, Korea.
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).
Conclusion:
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.
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