An international team of researchers found support for the 2011 Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines using over airflow limitation alone to classify patients with COPD, according to a new article in European Respiratory Journal. The authors believe their data contributes to a growing body of evidence vindicating the new guidelines, which were based primarily on expert opinion.
Investigators found that patients in the 4 new groups (A, B, C, and D) had distinct characteristics other than those used for classification. Patients in the high-symptom groups B and D had the highest prevalence of comorbidities and inflammation, as well as poorest quality of life and exercise capacity, while patients in the high-risk groups C and D had the greatest emphysema and the lowest arterial blood saturation.
The researchers also noted the new classification tended to shift patients upward in severity in comparison with the previous 2007 guidelines, which were based on FEV1 alone. Compared to the 2007 guidelines, the authors found the 2011 classification had a higher concordance probability for predicting exacerbations and hospitalizations, and was comparable for the prediction of all-cause mortality.
Over the course of the study, they found that while patients in the A and D classifications tended to stay in their initial group, B and C patients often changed group by year 3, with only 36% and 47%, respectively, still in the same group. The data show that patients in group B had equally poor outcomes with regard to hospitalizations and mortality to those in group C, despite better FEV1 and fewer exacerbations.
“We think that this is a clear example of how the new GOLD 2011 assessment proposal goes beyond FEV1 and identifies a group of patients who, despite the presence of moderate airflow limitation, are at high risk of mortality,” the authors conclude.