Clinical characteristics and outcomes in Japanese patients with COPD according to the 2017 GOLD classification: the Ishinomaki COPD Network Registry

PURPOSE: The GOLD report provides a framework for classifying COPD in a way that reflects its clinical impact and allows treatment recommendations. The GOLD 2017 proposes a new classification whereby patients are grouped as A–D according to their symptoms and history of exacerbations. However, the clinical characteristics and outcomes in these patients are not well documented. PATIENTS AND METHODS: In this prospective observational study, we analyzed data from the Ishinomaki COPD Network Registry. All patients with stable COPD were classified into the four groups defined by GOLD 2017. The patient demographics, clinical characteristics, number of exacerbations, and mortality rate during 1 year of follow-up were compared between the groups. RESULTS: Four hundred and one patients with stable COPD were identified. There were 240 patients (59.9%) in group A, 122 (30.4%) in group B, 16 (4.0%) in group C, and 23 (5.7%) in group D. Patients in groups B, C, and D had ORs of 2.95, 3.92, and 5.45, respectively, for risk of exacerbation relative to group A. Groups C and D experienced exacerbations more frequently, including exacerbations leading to hospital admission, than groups A and B (both P<0.001) during the 1-year follow-up period. Patients with a high risk of exacerbation (groups C and D) had a lower body mass index, showed more symptoms, used more respiratory medications, and had more severe airflow limitation than patients at low risk of exacerbation (groups A and B). Mortality was not different between the high-risk and low-risk groups. CONCLUSION: The results of our study provide evidence that the GOLD 2017 classification identifies patients with COPD at risk of exacerbations, including those requiring hospitalization, but has a poor ability to predict mortality.