Data support 2011 GOLD classifications
medwireNews: Researchers have found support for the multifactorial approach advocated by the 2011 Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines using over airflow limitation alone to classify patients with chronic obstructive pulmonary disease (COPD).
The study involved data from the observational, 3-year ECLIPSE study on 2101 patients who were categorized into GOLD 2011 groups according to the modified Medical Research Council score, forced expiratory volume in 1 second (FEV1), and the number of exacerbations in the prior year.
The team, led by Alvar Agusti (Universitat de Barcelona, Spain), found that patients in the four new groups (A, B, C, and D) had distinct characteristics other than those used for classification. In particular, 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 note that the new classification tended to shift patients upward in severity in comparison with the previous 2007 guidelines, which were based on FEV1 alone.
Over the course of the study, they found that while patients in the A and D classifications tended to stay in their initial group (57% and 78%, respectively), B and C patients often changed group by year 3, with only 36% and 47%, respectively, still in the same group.
And 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,” say Agusti and colleagues in the European Respiratory Journal.
And, in comparison with the 2007 guidelines, the authors found that the 2011 classification had a higher concordance probability for predicting exacerbations (0.59 vs 0.57) and hospitalizations (0.66 vs 0.63), and was comparable for the prediction of all-cause mortality (0.60 vs 0.61).
The authors conclude that the study contributes to a growing body of evidence vindicating the new guidelines, which were based primarily on expert opinion.
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013
By Kirsty Oswald, medwireNews Reporter