title: Prevalence of insomnia and associated factors in a community sample of elderly individuals in South Korea.
abstract: BACKGROUND
  Insomnia is a common psychiatric complaint among elderly individuals. This study investigates the prevalence and sociodemographic correlates of insomnia by considering a community sample of elderly individuals in South Korea.
  
  
  METHODS
  A face-to-face household survey was conducted in five regions of South Korea from June 2008 to August 2008. Among a total of 3,074 individuals aged 65 years and over, 2,002 participants were interviewed. The presence of insomnia was defined as having at least one of four sleep complaints that included difficulty in initiating sleep (DIS), difficulty in maintaining sleep (DMS), early morning awakening (EMA), and non-restorative sleep (NRS) more than three times per week in the last month. The Restless Legs Syndrome (RLS) Questionnaire, a short form of the Geriatric Depression scale (GDS), and a medical review of systems were implemented.
  
  
  RESULTS
  Insomnia was found in 29.2% of the participants. DIS, DMS, EMA, and NRS accounted for 19.4%, 21.7%, 19.6%, and 8.0% of the participants respectively. Insomnia accompanied by daytime consequences accounted for 17.1% of the participants. The participants who were females, had no education, lived alone, showed symptoms of RLS or depression, and had a lifetime history of physical illness were significantly more likely to report insomnia. The prevalence of DIS, DMS, EMA, or insomnia increased slightly with age, whereas that of NRS decreased slightly. The lifetime history of head trauma, hyperlipidemia, heart disease, anemia, or depression was significantly related to insomnia.
  
  
  CONCLUSIONS
  Sleep problems are common among elderly individuals and are closely related to their lifetime history of physical illness.
authors.affiliation: Department of Psychiatry, Inha University Hospital, Incheon, South Korea.
authors.forename: Won-Hyoung
authors.initials: WH
authors.lastname: Kim
authors.forename: Byung-Soo
authors.initials: BS
authors.lastname: Kim
authors.forename: Shyn-Kyum
authors.initials: SK
authors.lastname: Kim
authors.forename: Sung-Man
authors.initials: SM
authors.lastname: Chang
authors.forename: Dong-Woo
authors.initials: DW
authors.lastname: Lee
authors.forename: Maeng-Je
authors.initials: MJ
authors.lastname: Cho
authors.forename: Jae-Nam
authors.initials: JN
authors.lastname: Bae
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003625:Data Collection; D004522:Educational Status; D005260:Female; D006801:Humans; D008297:Male; D017533:Marital Status; D015995:Prevalence; D056910:Republic of Korea / Q000453:epidemiology; D012148:Restless Legs Syndrome / Q000453:epidemiology; D012737:Sex Factors; D007319:Sleep Initiation and Maintenance Disorders / Q000453:epidemiology*