Characteristics of 2017 GOLD COPD group A: a multicenter cross-sectional CAP study in Japan

Purpose: The 2017 GOLD ABCD classification shifts patients from groups C-D to A-B. Group A was the most widely distributed group in several studies. It would be useful to understand the characteristics for group A patients, but little has been reported concerning these issues. Patients and methods: This was a multicenter cross-sectional study using the COPD Assessment in Practice study database from 15 primary or secondary care facilities in Japan. We investigated the clinical characteristics of group A by stratification according to a mMRC grade 0 or 1. Results: In 1,168 COPD patients, group A patients accounted for approximately half of the patients. Compared with the groups B-D, group A was younger and had a higher proportion of males, higher pulmonary function, and higher proportion of monotherapy with long-acting muscarinic antagonist or long-acting beta-agonist. The prevalence of mMRC grade 1 patients was about two-thirds of group A. Compared with the mMRC 0 patients, mMRC 1 patients showed a tendency to have a higher proportion of exacerbations (P=0.054) and had a significantly lower pulmonary function. Regardless of the mMRC grade, 60% of group A patients were treated with monotherapy of long-acting muscarinic antagonist or long-acting beta-agonist. Conclusion: Group A patients accounted for approximately half of the patients, and they were younger, had higher pulmonary function, and had lower pharmacotherapy intensity compared with groups B-D. By stratifying according to the mMRC grade 0 or 1 in group A patients, there were differences in the exacerbation risk and airflow limitation.