title: Impact of insomnia on individual health dissatisfaction in Japan, South Korea, and Taiwan.
abstract: OBJECTIVE
  This study assessed the impact of insomnia on individual health dissatisfaction in Japan, South Korea, and Taiwan.
  
  
  METHODS
  Cross-sectional surveys with a face-to-face interview were conducted in Japan (n = 1414), South Korea (n = 1007), and Taiwan (n = 785). Participants completed a questionnaire on general health dissatisfaction and insomnia symptoms. Insomnia was defined as having at least one of three types of insomnia symptoms (i.e., difficulty initiating sleep, difficulty maintaining sleep, and early-morning awakening). Information on sociodemographic characteristics (i.e., sex, age, education level, and household income) was also collected.
  
  
  METHODS
  N/A.
  
  
  METHODS
  A nationwide sample of subjects aged 20 years or older
  
  
  METHODS
  N/A.
  
  
  RESULTS
  The age-adjusted prevalence of insomnia "lasting more than 2 weeks" was 4.0% in Japan, 9.9% in South Korea, and 10.3% in Taiwan. Insomnia was an independent contributor to health dissatisfaction after adjusting for sociodemographic characteristics in the three countries, with odds ratios of 2.54 (95% CI, [1.51-4.28]) in Japan, 2.15 (95% CI [1.33-3.48]) in South Korea, and 2.31 (95%CI [1.37-3.89]) in Taiwan. A multivariate logistic analysis showed that the sociodemographic characteristics that significantly influenced health dissatisfaction varied among nations-including older age and low education level in Japan and female gender and middle-income level in South Korea. No independent variables were selected in Taiwan.
  
  
  CONCLUSIONS
  Insomnia is closely linked to health dissatisfaction in the three Asian countries, with variation according to social and demographic factors.
authors.affiliation: Department of Hygiene and Public Health, Teikyo University School of Medicine, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Nomura
authors.forename: Kazue
authors.initials: K
authors.lastname: Yamaoka
authors.forename: Mutsuhiro
authors.initials: M
authors.lastname: Nakao
authors.forename: Eiji
authors.initials: E
authors.lastname: Yano
mesh_terms: D000328:Adult; D001294:Attitude to Health / Q000208:ethnology*; D003430:Cross-Sectional Studies; D005260:Female; D006304:Health Status; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007723:Korea / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D015995:Prevalence; D007319:Sleep Initiation and Maintenance Disorders / Q000453:epidemiology / Q000208:ethnology*; D011795:Surveys and Questionnaires; D013624:Taiwan / Q000453:epidemiology