title: Epidemiology of insomnia in korean adults: prevalence and associated factors.
abstract: OBJECTIVE
  Insomnia is a common complaint in adults. However, large epidemiologic studies of insomnia involving Asian populations are rarely reported. We performed an epidemiologic study of insomnia in a large Korean adult population.
  
  
  METHODS
  A total of 5,000 subjects (2,470 men and 2,530 women) were interviewed by telephone. A representative sample of subjects aged 20 to 69 years was constituted according to a stratified, multistage random sampling method. Insomnia was defined as either any difficulty getting to sleep or getting back to sleep after waking in the night.
  
  
  RESULTS
  More than one fifth (n=1,141, 22.8%) of the 5,000 subjects complained of insomnia, with the prevalence being significantly higher in women (25.3%) than in men (20.2%, p<0.001). Logistic regression revealed that the prevalence of insomnia increased significantly with age (p<0.001), being higher in those aged 60-69 years than in those aged 20-29 years (OR=2.368, 95% CI=1.762-3.182, p<0.001), and was lower in those with a monthly income of >4.5 million Korean won than in those with an income of <1.5 million Korean won (OR=0.689, 95% CI=0.523-0.906, p<0.01).
  
  
  CONCLUSIONS
  Insomnia is a common complaint in Korean adults, and its prevalence is similar to that in adults in Western countries.
authors.affiliation: Department of Neurology, Dongsan Medical Center, Keimyung University, Daegu, Korea.
authors.forename: Yong Won
authors.initials: YW
authors.lastname: Cho
authors.forename: Won Chul
authors.initials: WC
authors.lastname: Shin
authors.forename: Chang Ho
authors.initials: CH
authors.lastname: Yun
authors.forename: Seung Bong
authors.initials: SB
authors.lastname: Hong
authors.forename: Juhan
authors.initials: J
authors.lastname: Kim
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Earley