title: The International Classification of Functioning, Disability and Health: development of capacity and performance scales.
abstract: OBJECTIVE
  There has been no attempt to obtain a continuous summary measure of disability from the checklist of the International Classification of Functioning, Disability and Health (ICF). Our objective was to assess whether valid scales of Capacity and Performance could be developed from the "Activities and Participation" domain of the ICF checklist.
  
  
  METHODS
  A multicenter, observational study of 1,092 patients with 12 different chronic conditions from five European countries was conducted. Exploratory and confirmatory factor analyses were performed to assess the underlying factor structure. Reliability and validity of the Capacity and Performance scales were evaluated. Construct validity was assessed calculating effect size coefficients between extreme severity groups (discriminant ability).
  
  
  RESULTS
  The good fit of the confirmatory factor model supported the global scales of Capacity and Performance and their "Psychosocial" and "Physical" subscales. Reliability was excellent (coefficients=0.79-0.92). Effect sizes of most conditions were large for the Capacity global scale (0.50-3.05), and slightly lower for the Performance global scale (0.45-2.57).
  
  
  CONCLUSIONS
  Our findings support the measurement model, reliability, and validity of the Capacity and Performance scales. Summary measures of functioning based on the ICF can be obtained using these scales, which should facilitate their incorporation in clinical and epidemiological studies.
authors.affiliation: Health Services Research Unit, IMIM-Hospital del Mar, Barcelona, Spain.
authors.forename: Josue
authors.initials: J
authors.lastname: Almansa
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Ayuso-Mateos
authors.forename: Olatz
authors.initials: O
authors.lastname: Garin
authors.forename: Somnath
authors.initials: S
authors.lastname: Chatterji
authors.forename: Nenad
authors.initials: N
authors.lastname: Kostanjsek
authors.forename: Jordi
authors.initials: J
authors.lastname: Alonso
authors.forename: Jose Maria
authors.initials: JM
authors.lastname: Valderas
authors.forename: Alarcos
authors.initials: A
authors.lastname: Cieza
authors.forename: Alberto
authors.initials: A
authors.lastname: Raggi
authors.forename: Olga
authors.initials: O
authors.lastname: Svestkova
authors.forename: Helena
authors.initials: H
authors.lastname: Burger
authors.forename: Vittorio
authors.initials: V
authors.lastname: Racca
authors.forename: Eduard
authors.initials: E
authors.lastname: Vieta
authors.forename: Matilde
authors.initials: M
authors.lastname: Leonardi
authors.forename: Montserrat
authors.initials: M
authors.lastname: Ferrer
mesh_terms: D000203:Activities of Daily Living; D004185:Disability Evaluation; D006233:Persons with Disabilities; D005062:European Union; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D011634:Public Health; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards*