Le LAK, et al. - Researchers studied 912 COPD patients with FEV1 less than 80% of the predicted in order to compare the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2011, GOLD 2017 ABCD, and GOLD 2017 1A-4D groups in terms of their distribution and prediction of mortality and hospitalizations. They found that, in comparison to the GOLD 2011 classification, the GOLD 2017 classification doubled the prevalence of group B and halved the prevalence of groups C and D in a clinically relevant sample of COPD patients. Compared to GOLD 2017 ABCD and GOLD 2011, better prediction of respiratory mortality and respiratory hospitalization was reported for GOLD 2017 2A–4D considering airflow limitation severity.