title: Structural equation modelling for the effect of physical exercise on excessive daytime sleepiness.
abstract: OBJECTIVE
  The present study aimed to examine the effect of physical exercise on excessive daytime sleepiness (EDS) which is a significant public health problem.
  
  
  METHODS
  This is a population-based cohort study.
  
  
  METHODS
  We hypothesized that those who engage in regular exercise would have lower chances of dozing in the daytime and examined causal relationships between EDS and known risk factors for EDS using structural equation model (SEM).
  
  
  RESULTS
  We found that causal relationships from both depression and sleep quality to EDS were relatively weaker in those who regularly engage in physical exercise, which resulted in lower chances of having EDS.
  
  
  CONCLUSIONS
  Regular exercise may play a protective role in EDS prevention.
authors.affiliation: Data Science and Big Data Analysis, Division of Economics & Statistics, College of Public Policy, Korea University, Sejong, 30019, Korea.
authors.forename: A M
authors.initials: AM
authors.lastname: Kwon
authors.affiliation: Division of Pulmonary, Sleep and Critical Care Medicine, Department of Internal Medicine, Korea University, Seoul, 02841, Korea; Institute of Human Genomic Study, Korea University Ansan Medical Center, Korea University, Ansan, 15355, Korea. Electronic address: chol-shin@korea.ac.kr.
authors.forename: C
authors.initials: C
authors.lastname: Shin
mesh_terms: D016022:Case-Control Studies; D015331:Cohort Studies; D003863:Depression / Q000453:epidemiology; D006970:Disorders of Excessive Somnolence / Q000453:epidemiology*; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D012307:Risk Factors; D012890:Sleep / Q000502:physiology
keywords: Causality; Cohort study; Excessive daytime sleepiness; Physical exercise; Structural equation modelling