title: Severity, timing, and structure of disability.
abstract: OBJECTIVE
  Severity and timing are key aspects of disability experience for individuals. They also generate a population's disability structure (prevalence, counts, patterns). We study links among severity, duration, and structure for community-dwelling adults in the US.
  
  
  METHODS
  The data source is the National Health Interview Survey Disability Supplement. Disabilities in personal care (ADL), household management (IADL), and physical functions (PLIM) are analyzed.
  
  
  RESULTS
  Many combinations of disabilities are possible, but just a few are frequent; the top-10 patterns cover 70% of ADL, 89% of IADL, and 47% of PLIM disabled adults. Hierarchical patterns are common for ADLs and IADLs. People with many disabilities also have more-severe ones, and their disabilities often started at the same time.
  
  
  CONCLUSIONS
  Disability structure reflects severity and timing of specific disabilities, sometimes strongly, and other times weakly due to exit processes from the community. Assumptions that disability occurs in "hard" tasks first and "easy" ones last, and that hard-and-early connotes mild disability whereas easy-and-late connotes severe, need direct empirical testing.
authors.affiliation: Institute of Gerontology, University of Michigan, Ann Arbor, USA. verbrugg@umich.edu
authors.forename: Lois M
authors.initials: LM
authors.lastname: Verbrugge
authors.forename: Li-Shou
authors.initials: LS
authors.lastname: Yang
authors.forename: Lucia
authors.initials: L
authors.lastname: Juarez
mesh_terms: D000203:Activities of Daily Living / Q000145:classification; D000328:Adult; D003430:Cross-Sectional Studies; D003625:Data Collection / Q000706:statistics & numerical data; D004185:Disability Evaluation; D006233:Persons with Disabilities / Q000145:classification / Q000706:statistics & numerical data*; D006306:Health Surveys; D006796:Household Work / Q000145:classification; D006801:Humans; D011159:Population Surveillance; D012648:Self Care / Q000145:classification; D014481:United States / Q000453:epidemiology