Comparison between the disease-specific Airways Questionnaire 20 and the generic 15D instruments in COPD

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.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.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.Chronic obstructive pulmonary disease (COPD), a serious debilitating condition with worldwide prevalence of 8-20% today, is estimated to be the third leading cause of death by year 2020 [1-3]. Respiratory conditions in COPD such as emphysema or chronic bronchitis, or both, are related to (nearly) irreversible airway obstruction causing chronic cough or phlegm and breathlessness (dyspnea) [4]. Persistent and progressive dyspnea forces into lifestyle adjustments, impairs patients' health-related quality of life (HRQoL), and leads to disability. Since there is no medical or surgical cure for COPD with prognostic significance, one of the principal goals of the management of COPD is to improve patient's HRQoL by reliev