title: Disability in the oldest-old:  incidence and risk factors in the 90+ study.
abstract: OBJECTIVE
  : To measure the incidence of disability in individuals aged 90 years and older and examine factors that may increase risk of disability.
  
  
  METHODS
  : The 90+ Study, a longitudinal study of aging, initiated in January 2003 with follow-up through May 2009.
  
  
  METHODS
  : A total of 216 nondisabled, prospectively followed participants who were aged 90 years or older at baseline.
  
  
  METHODS
  : The incidence of disability was measured as needing help on one or more activities of daily living and calculated using person years. Risk factors were examined by using a Cox proportional hazards analysis.
  
  
  RESULTS
  : The overall incidence of disability was 16.4% per year (95% confidence interval: 13.3-20.0) and did not differ by gender. Disability incidence increased with age from 8.3% in the 90-94 age group to 25.7% in the 95 years and older age group. Several factors were associated with increased risk of disability, including history of congestive heart failure, depression, poor self-rated quality of life, and cognitive impairment.
  
  
  CONCLUSIONS
  : Disability incidence is high and increases rapidly with age in the oldest-old, with rates essentially tripling between ages 90-94 years and 95+ years. Some factors associated with increased risk of disability in younger elderly continue to be risk factors in the oldest-old. Because of the tremendous social and financial impact of disability and the rapid growth of the oldest-old, the development of strategies to delay disability in the elderly should be a priority for healthcare research.
authors.affiliation: Department of Neurology, University of California Irvine, CA 92697, USA. danb@uci.edu
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Berlau
authors.forename: Maria M
authors.initials: MM
authors.lastname: Corrada
authors.forename: Carrie B
authors.initials: CB
authors.lastname: Peltz
authors.forename: Claudia H
authors.initials: CH
authors.lastname: Kawas
mesh_terms: D000203:Activities of Daily Living; D000369:Aged, 80 and over; D000375:Aging; D002140:California / Q000453:epidemiology; D003072:Cognition Disorders / Q000453:epidemiology; D015331:Cohort Studies; D003863:Depression / Q000453:epidemiology; D006233:Persons with Disabilities / Q000706:statistics & numerical data*; D005260:Female; D015577:Geriatric Assessment; D006333:Heart Failure / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D011788:Quality of Life; D012307:Risk Factors