title: Benchmarking functional status in older adults.
abstract: OBJECTIVE
  To characterize the manner of functional status difficulties with age across multiple functional domains: lower extremity function, upper extremity function, and cognitive/social function. Construct validity of a functional status measure composed of these domains was assessed as part of this goal.
  
  
  METHODS
  Cross-sectional survey of the community-dwelling civilian population in the United States.
  
  
  METHODS
  Community.
  
  
  METHODS
  Community-dwelling adults aged 60 years and older (N=7968).
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Model fit of a 20-item functional status measure to a confirmatory factor analysis model was assessed with the root mean square error of approximation and the root mean square residual. Functional status benchmarks for age were developed with curves plotting activity difficulty percentiles versus age for the general U.S. population.
  
  
  RESULTS
  The 20-item activity difficulty index modeled as a 3-factor construct had a root mean square error of approximation of .045 and a root mean squared residual of .052, indicating good fit. Benchmarks based on percentiles show that the median activity difficulty score is quite low for the full range studied but that there is a steady increase with increasing age. The domain regarding cognition and social function appeared to be less sensitive than the upper and lower extremity skills domains to increasing age.
  
  
  CONCLUSIONS
  A broad measure of difficulty with functional activities can be meaningfully treated as a 3-domain construct. The scores represented by the index measuring this construct can be used to compare patients to a national sample of age-matched individuals to assess functional status using normative values.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA; Department of Physical Medicine and Rehabilitation, Massachusetts General Hospital, Harvard Medical School, Boston, MA; Division of Physical Medicine and Rehabilitation, Department of Medicine, Newton Wellesley Hospital, Newton, MA. Electronic address: pbgerrard@gmail.com.
authors.forename: Paul
authors.initials: P
authors.lastname: Gerrard
authors.affiliation: Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA; Department of Physical Medicine and Rehabilitation, Massachusetts General Hospital, Harvard Medical School, Boston, MA.
authors.forename: John
authors.initials: J
authors.lastname: Luce
authors.affiliation: Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA; Department of Physical Medicine and Rehabilitation, Massachusetts General Hospital, Harvard Medical School, Boston, MA.
authors.forename: Jonathan F
authors.initials: JF
authors.lastname: Bean
authors.affiliation: Health and Disability Research Institute, Boston University School of Public Health, Boston, MA.
authors.forename: Alan M
authors.initials: AM
authors.lastname: Jette
authors.affiliation: Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA; Department of Physical Medicine and Rehabilitation, Massachusetts General Hospital, Harvard Medical School, Boston, MA.
authors.forename: Ross
authors.initials: R
authors.lastname: Zafonte
mesh_terms: D000203:Activities of Daily Living; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology*; D019985:Benchmarking; D003071:Cognition / Q000502:physiology*; D003430:Cross-Sectional Studies; D005163:Factor Analysis, Statistical; D005260:Female; D006304:Health Status; D006305:Health Status Indicators; D006801:Humans; D035002:Lower Extremity / Q000502:physiology; D008297:Male; D008875:Middle Aged; D058992:Social Participation; D014481:United States; D034941:Upper Extremity / Q000502:physiology
keywords: Factor analysis, statistical; Geriatric assessment; Geriatrics; Rehabilitation