title: Insomnia subtypes and their relationship to excessive daytime sleepiness in Brazilian community-dwelling older adults.
abstract: OBJECTIVE
  To investigate the association between different types of insomnia as exposures and excessive daytime sleepiness (EDS) as a binary outcome in older Brazilian residents.
  
  
  METHODS
  The baseline examination of the Bambuí Health and Ageing Study (BHAS), which is an ongoing population-based prospective cohort study of older adults.
  
  
  METHODS
  Bambuí (15,000 inhabitants), a city in the State of Minas Gerais, Southeast Brazil
  
  
  METHODS
  All residents aged ≥ 60 years were eligible to take part in the BHAS baseline. Of 1742 residents identified who were ≥ 60 years, 1606 (92.2%) were interviewed and received comprehensive examinations of health status.
  
  
  METHODS
  None.
  
  
  RESULTS
  EDS was defined as the presence of sleepiness ≥ 3 times per week in the last month, causing any interference in usual activities. All insomnia subtypes were significantly associated with EDS in unadjusted analyses, and these associations were only modestly altered after adjusting incrementally for the other covariates. In a final model, the 3 insomnia subtypes were entered into a fully adjusted model simultaneously to investigate mutual independence, giving prevalence ratios of 1.63 (95% CI 1.14-2.31) for initial insomnia, 2.13 (95% CI 1.48-3.07) for middle insomnia, and 1.36 (95% CI 0.94-1.96) for terminal insomnia. The population attributable fractions for initial, middle, and terminal insomnia on prevalence of EDS were 17.6%, 32.9%, and 9.7%, respectively.
  
  
  CONCLUSIONS
  Middle insomnia emerged as the insomnia subtype most strongly associated with EDS. Further research is required to clarify causal pathways underlying this cross-sectional association.
authors.affiliation: Psychiatry Residency Programme - Psychopharmacology Course, Social Security Institute of the Civil Servants of Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Cláudia
authors.initials: C
authors.lastname: Hara
authors.forename: Robert
authors.initials: R
authors.lastname: Stewart
authors.forename: Maria Fernanda
authors.initials: MF
authors.lastname: Lima-Costa
authors.forename: Fábio Lopes
authors.initials: FL
authors.lastname: Rocha
authors.forename: Cíntia
authors.initials: C
authors.lastname: Fuzikawa
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Uchoa
authors.forename: Josélia O A
authors.initials: JO
authors.lastname: Firmo
authors.forename: Érico
authors.initials: É
authors.lastname: Castro-Costa
mesh_terms: D000368:Aged; D000375:Aging; D001938:Brazil / Q000453:epidemiology; D015331:Cohort Studies; D015897:Comorbidity; D006970:Disorders of Excessive Somnolence / Q000453:epidemiology*; D005260:Female; D006304:Health Status; D006801:Humans; D008019:Life Style; D008297:Male; D017533:Marital Status / Q000706:statistics & numerical data; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D012111:Residence Characteristics; D017678:Sex Distribution; D007319:Sleep Initiation and Maintenance Disorders / Q000188:drug therapy / Q000453:epidemiology*; D011795:Surveys and Questionnaires