title: Construct validity of the late life function and disability instrument for adults with chronic conditions.
abstract: OBJECTIVE
  To evaluate the validity of the late life function and disability instrument (LLFDI) when applied to adults aged 44-65 years with chronic conditions.
  
  
  METHODS
  We applied a convergent cross-sectional construct validity design to examine the association between the LLFDI subscales and the medical outcomes study (MOS) 36-Item Health Survey Physical Component Score (SF36 PCS), MOS Physical Functioning scale (PF10), 2-minute walk distance (2MWD) and 8-foot walk test (8FWT).
  
  
  METHODS
  Our sample consisted of 174 community-dwelling adults age 45-65 years with one or more chronic conditions.
  
  
  METHODS
  Participants were enrolled at a multidisciplinary family health practice.
  
  
  RESULTS
  The LLFDI function correlated strongly with the PF10 (r = 0.84) and moderately with the 2MWD (r = 0.53) and 8FWT (r = -0.48). The LLFDI disability limitation correlated moderately with the SF36 PCS, 2MWD and 8FWT (r = 0.67, 0.45, -0.32, respectively). The LLFDI disability frequency correlated moderately with the SF36 PCS, 2MWD and 8FWT (r = 0.44, 0.33, -0.31). Ninety-five percent confidence intervals on all correlation coefficients excluded zero.
  
  
  CONCLUSIONS
  Cross-sectional convergent validity of the LLFDI was supported when applied to adults 45-65 years of age with chronic conditions.
authors.affiliation: School of Rehabilitaton Science, McMaster University, Hamilton, Ontario, Canada L8S 1C7. handc@mcmaster.ca
authors.forename: Carri
authors.initials: C
authors.lastname: Hand
authors.forename: Julie
authors.initials: J
authors.lastname: Richardson
authors.forename: Lori
authors.initials: L
authors.lastname: Letts
authors.forename: Paul
authors.initials: P
authors.lastname: Stratford
mesh_terms: D000203:Activities of Daily Living; D000222:Adaptation, Physiological; D000223:Adaptation, Psychological; D000328:Adult; D000368:Aged; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D006233:Persons with Disabilities; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D008875:Middle Aged; D016138:Walking