Evaluation of the chronic obstructive pulmonary disease assessment test in Japanese outpatients
Authorship and contributorship
All authors contributed to the study conception, design, data acquisition and interpretation of data, manuscript drafting, revising and final approval.
The institutional review boards of Yokohama City University Hospital and the Fraternity Memorial Hospital approved this study. All patients provided written informed consent before their entry into the study.
No fund was provided for this study.
Conflict of interest
Authors have nothing to declare.
The Chronic Obstructive Pulmonary Disease (COPD) Assessment Test (CAT) is a quality-of-life (QOL) questionnaire that proved to correlate with St. George's Respiratory Questionnaire. Correlations between CAT scores and other COPD parameters have not been thoroughly evaluated in Japanese outpatients.
Cross-sectional study of 85 outpatients with COPD at a Japanese community-based hospital.
We observed 70 men and 15 women, whose average age was 72.0 ± 9.0 years. Mean forced expiratory volume in 1 s (FEV1) (% predicted) was 45.8 ± 14.7%. Mean CAT score was 10.1 ± 7.9 (range: 0–31). We calculated Spearman's rank correlation coefficient for CAT score and the following variables: r = 0.81 for ‘the Body Mass Index, Airflow Obstruction, Dyspnea and Exercise Capacity Index’; r = −0.05 for body mass index; r = −0.56 for FEV1 (% predicted); r = 0.88 for Modified Medical Research Council Dyspnea Scale; r = −0.71 for 6-min walk distance; r = 0.68 for ‘the Age, Dyspnoea,and Airflow Obstruction Index’; and r = −0.40 for oxygen saturation in artery. Each COPD parameter, except for body mass index, had a significant (P < 0.001) correlation with the CAT score.
The CAT score, which is obtainable by a simple questionnaire originally designed for QOL assessment, had strong correlations with airflow obstruction, dyspnea, exercise tolerance, prognostic index and oxygenation in Japanese outpatients.