title: How Should Disability Be Measured in Older Adults? An Analysis from the Boston Rehabilitative Impairment Study of the Elderly.
abstract: OBJECTIVE
  To determine and compare the predictive validity and responsiveness of the Late-Life Function and Disability Instrument (LLFDI) frequency and limitation dimensions in assessing two critical dimensions of disability: frequency of and limitations in performance of major life roles.
  
  
  METHODS
  Secondary analysis of 2-year follow-up data from the Boston Rehabilitative Impairment Study of the Elderly.
  
  
  METHODS
  Primary care.
  
  
  METHODS
  Community-dwelling older adults (≥65) (n = 430) at risk of mobility decline.
  
  
  METHODS
  The LLFDI frequency and limitation dimensions, self-rated health, hospitalizations, and emergency department (ED) visits over 2 years. Responsiveness measures included effect size (ES) estimates and minimal detectable change (MDC) scores.
  
  
  RESULTS
  The LLFDI frequency dimension predicted low self-rated health (odds ratio (OR) = 0.51, P < .001), hospitalizations (OR = 0.68, P < .001), and ED visits (OR = 0.73, P = .003) over 2 years, whereas the limitation dimension did not. The absolute ES was 0.63 for the frequency dimension and 0.81 for the limitation dimension. The proportion of subjects with a decline greater than or equal to the MDC was 10.6% for the frequency dimension and 14.2% for the limitation dimension. For participants who improved greater than or equal to the MDC, the proportion was 1.7% for the frequency dimension and 15.3% for the limitation dimension.
  
  
  CONCLUSIONS
  Frequency of participation in major life roles was a better predictor of adverse outcomes than perceived limitations, although limitations appeared to be more responsive to meaningful change. These results can be used to guide the selection of the most appropriate metric for measuring disability in geriatric research.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Harvard Medical School, Cambridge, Massachusetts.|Spaulding Rehabilitation Hospital, Boston, Massachusetts.|Health and Disability Research Institute, School of Public Health, Boston University, Boston, Massachusetts.
authors.forename: Marla K
authors.initials: MK
authors.lastname: Beauchamp
authors.affiliation: Department of Physical Medicine and Rehabilitation, Harvard Medical School, Cambridge, Massachusetts.|Spaulding Rehabilitation Hospital, Boston, Massachusetts.
authors.forename: Jonathan F
authors.initials: JF
authors.lastname: Bean
authors.affiliation: Department of Physical Medicine and Rehabilitation, Harvard Medical School, Cambridge, Massachusetts.|Spaulding Rehabilitation Hospital, Boston, Massachusetts.|Health and Disability Research Institute, School of Public Health, Boston University, Boston, Massachusetts.
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Ward
authors.affiliation: Spaulding Rehabilitation Hospital, Boston, Massachusetts.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Kurlinski
authors.affiliation: Health and Disability Research Institute, School of Public Health, Boston University, Boston, Massachusetts.
authors.forename: Nancy K
authors.initials: NK
authors.lastname: Latham
authors.affiliation: Health and Disability Research Institute, School of Public Health, Boston University, Boston, Massachusetts.
authors.forename: Alan M
authors.initials: AM
authors.lastname: Jette
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001900:Boston; D004185:Disability Evaluation; D006233:Persons with Disabilities / Q000534:rehabilitation* / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D015577:Geriatric Assessment / Q000379:methods*; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D051346:Mobility Limitation; D011237:Predictive Value of Tests; D011594:Psychometrics; D011597:Psychomotor Performance; D011795:Surveys and Questionnaires / Q000592:standards*
keywords: community-dwelling older adults; disability; minimal detectable change; responsiveness; validity