title: Comparison between the disease-specific Airways Questionnaire 20 and the generic 15D instruments in COPD.
abstract: BACKGROUND
  Given that the assessment of health-related quality of life (HRQoL) is an essential outcome measure to optimize chronic obstructive pulmonary disease (COPD) patient management, there is a need for a short and fast, reliable and valid instrument for routine use in clinical practice. The objective of this study was to analyse the relationship between the disease-specific Airways questionnaire (AQ20) and the generic 15D health-related quality of life (HRQoL) instrument simultaneously in a large cohort of patients with COPD. We also compare the HRQoL of COPD patients with that of the general population.
  
  
  METHODS
  The AQ20 and 15D were administered to 739 COPD patients representing an unselected hospital-based COPD population. The completion rates and validity of, and correlations among the questions and dimension scores were examined. A factor analysis with varimax rotation was performed in order to find subsets of highly correlating items of the questionnaires.
  
  
  RESULTS
  The summary scores of AQ20 and 15D were highly correlated (r = - 0.71, p < 0.01). In AQ20 over 50% of patients reported frequent cough, breathlessness during domestic work, and chest problem limiting their full enjoyment of life. 15D results showed a noteworthy decrease of HRQoL in breathing, mobility, sleeping, usual activities, discomfort and symptoms, vitality, and sexual activity (scores ≤ 0.75). Compared to the age- and gender-standardized Finnish general population, the COPD patients were statistically significantly worse off on 13 of 15 dimensions.
  
  
  CONCLUSIONS
  The AQ20 and 15D summary scores are comparable in terms of measuring HRQoL in COPD patients. The data support the validity of 15D to measure the quality of life in COPD. COPD compromises the HRQoL broadly, as reflected by the generic instrument. Both questionnaires are simple and short, and could easily be used in clinical practice with high completion rates.
authors.affiliation: Department of Medicine, Pulmonary Division, Helsinki University Central Hospital, Haartmaninkatu 4, Helsinki, Finland. witold.mazur@helsinki.fi
authors.forename: Witold
authors.initials: W
authors.lastname: Mazur
authors.forename: Henna
authors.initials: H
authors.lastname: Kupiainen
authors.forename: Janne
authors.initials: J
authors.lastname: Pitkäniemi
authors.forename: Maritta
authors.initials: M
authors.lastname: Kilpeläinen
authors.forename: Harri
authors.initials: H
authors.lastname: Sintonen
authors.forename: Ari
authors.initials: A
authors.lastname: Lindqvist
authors.forename: Vuokko L
authors.initials: VL
authors.lastname: Kinnula
authors.forename: Tarja
authors.initials: T
authors.lastname: Laitinen
mesh_terms: D000368:Aged; D015331:Cohort Studies; D005163:Factor Analysis, Statistical; D005260:Female; D005387:Finland; D006760:Hospitalization; D006801:Humans; D008168:Lung / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology / Q000523:psychology; D019984:Quality Indicators, Health Care; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires