title: Assessing disability in older adults: the effects of asking questions with and without health attribution.
abstract: OBJECTIVE
  To determine the effects of using questions with and without health attribution on scores derived from a self-report disability instrument.
  
  
  METHODS
  We administered the disability component of the Late Life Function and Disability Instrument to 75 community-dwelling older adults. Then, we administered the same 16 questions with attribution to specific health conditions. We used a series of analytic methods including weighted Kappa coefficient, Bowker's Test of Symmetry and Rasch analysis to assess the effects of attribution formats.
  
  
  RESULTS
  A higher prevalence of disability was reported in the non-health attributed compared with the health attributed questions (t = 5.76; p < 0.001, 95% CI 3.8-7.8). Item analyses indicated that participants were significantly more likely to report disability on the non-health attributed version on 4 of the 16 questions.
  
  
  CONCLUSIONS
  For community-dwelling older adults, the use of a non-health attribution format may be preferable in instruments designed to assess prevalence of disability from contributing factors other than just health.
authors.affiliation: Center for Rehabilitation Effectiveness, Sargent College of Health and Rehabilitation Sciences, Boston University, Boston, MA 02215, USA. nicdubuc@bu.edu
authors.forename: Nicole
authors.initials: N
authors.lastname: Dubuc
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Haley
authors.forename: Jill T
authors.initials: JT
authors.lastname: Kooyoomjian
authors.forename: Alan M
authors.initials: AM
authors.lastname: Jette
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000375:Aging / Q000523:psychology*; D003627:Data Interpretation, Statistical; D004185:Disability Evaluation; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D011795:Surveys and Questionnaires