Validation of the Clinical COPD Questionnaire in Taiwan

Health status improvement is a critical treatment goal for physicians managing chronic obstructive pulmonary disease (COPD). Numerous instruments to measure the disease-specific health-related quality of life (HRQOL) for patients with COPD have been used in daily clinical practice. The Clinical COPD Questionnaire (CCQ) is one of these recommended by the Global Initiative for Chronic Obstructive Lung Disease (GOLD). This study examined the psychometric properties of the CCQ in patients with COPD in Taiwan. A descriptive, cross-sectional design was conducted. Data were collected in a secondary care unit. We administered the CCQ, the modified Medical Research Council (mMRC) dyspnea scale, and the 12-item Short Form Health Survey (SF-12) for patients with COPD. Reliability was assessed using Cronbach's alpha and item-total correlation coefficients. Construct validity was assessed using confirmatory factor analysis (CFA) and testing the hypothesis that severity of dyspnea measured using the mMRC dyspnea scale is associated with the CCQ scores. Convergent validity was assessed by testing the correlation between the CCQ and the SF-12. Discriminant validity was assessed to differentiate among the classifications of COPD Groups A to D. A total of 114 subjects were recruited in the study. Cronbach's alpha was high (0.90) for the total score of the CCQ. Significant correlations were found between the CCQ scores and those of the mMRC dyspnea scale (ρ = 0.67) and domains of the SF-12 (ρ = -0.44 to -0.75). Furthermore, the CCQ scores showed a significant difference among the classifications of COPD Groups A to D. CFA confirmed the construct validity, with a good model fit. Good to excellent psychometric properties of the Chinese Version CCQ were demonstrated in the study. Wide usage of the Chinese Version CCQ for Taiwanese COPD patients can be recommended in daily clinical practice or clinical trials.