In a recent study of more than 33,000 Danish patients older than age 30 with COPD, researchers led by Anne Gedebjerg, MD, found that the GOLD 2017 ABCD classification did not predict all-cause and respiratory mortality more accurately than previous GOLD iterations from 2007 and 2011. Area under the curve for all-cause mortality was 0.61 for GOLD 2007, 0.61 for GOLD 2011, and 0.63 for GOLD 2017, while the area under the curve for respiratory mortality was 0.64 for GOLD 2007, 0.63 for GOLD 2011, and 0.65 for GOLD 2017 (Lancet Respir Med. 2018 Jan;6[3]:204-12).
However, when the spirometric stages 1-4 were combined with the A to D groupings based on symptoms and exacerbations, the 2017 classification predicted mortality with greater accuracy, compared with previous iterations (P less than .0001). “My practice is very much like this paper,” Dr. Iftikhar said. “I use both the spirometric grade and the ABCD grouping to specify which ‘group’ and ‘grade’ my patient belongs to. I think future investigators need to combine ABCD with spirometry classification to see how we can improve the classification system.”
In a commentary published in the same issue of the Lancet Respiratory Medicine as the large Danish study, Joan B. Soriano, MD, PhD, wrote that the 2011 GOLD guideline’s collapse of four spirometric thresholds (greater than 80%, 50%-80%, 30%-50%, and less than 30%) into just two (greater than 50% or 50% or less) “reduced the system’s ability to inform and predict mortality from the short term up to 10 years” (Lancet Respir Med. 2018 Jan;6[3]:165-6).
Lung function remains the best available biomarker for life expectancy in both patients with COPD and the general population,” wrote Dr. Soriano, a respiratory medicine researcher based in Madrid, Spain.