title: Content comparison of health-related quality of life instruments for COPD.
abstract: BACKGROUND
  Due to the increasing importance of quality of life assessments in chronic obstructive pulmonary disease (COPD) patients, and the increased use of the International Classification of Functioning, Disability and Health (ICF) for comparative purposes it is essential to understand the relationship between health-related quality of life (HRQL) instruments and the ICF.
  
  
  OBJECTIVE
  The objective of this study was to compare the content of recommended COPD-specific HRQL instruments using the ICF as reference. COPD-specific instruments mentioned in widely accepted guidelines were linked to the ICF using standardized linking rules. The degree of agreement between various health professionals was assessed by calculating the kappa statistic.
  
  
  RESULTS
  Eleven instruments were included. They varied strongly in the number of concepts contained and the number of ICF categories used to map these concepts. A total of 548 concepts were identified and linked to 60 different ICF categories. Only the single category 'dyspnea' was covered by all instruments, whilst 21 categories were unique to specific instruments. The relationships of the measures with the ICF were identified.
  
  
  CONCLUSIONS
  This study may aid researchers and clinicians to choose the most appropriate instrument for a specific purpose as well as help compare studies that have used different instruments for HRQL assessment.
authors.affiliation: Department of Internal Medicine, University Hospital Bern, 3010 Bern, Switzerland.
authors.forename: Armin
authors.initials: A
authors.lastname: Stucki
authors.forename: Gerold
authors.initials: G
authors.lastname: Stucki
authors.forename: Alarcos
authors.initials: A
authors.lastname: Cieza
authors.forename: Macé M
authors.initials: MM
authors.lastname: Schuurmans
authors.forename: Nenad
authors.initials: N
authors.lastname: Kostanjsek
authors.forename: Jörg
authors.initials: J
authors.lastname: Ruof
mesh_terms: D000203:Activities of Daily Living; D004185:Disability Evaluation; D006305:Health Status Indicators; D006801:Humans; D011594:Psychometrics; D029424:Pulmonary Disease, Chronic Obstructive / Q000523:psychology / Q000534:rehabilitation*; D011788:Quality of Life; D015203:Reproducibility of Results; D012720:Severity of Illness Index