Prediction of the Clinical Course of Chronic Obstructive Pulmonary Disease, Using the New GOLD Classification

Abstract

The new Global Initiative for Obstructive Lung Disease (GOLD) stratification of chronic obstructive pulmonary disease (COPD) into categories A, B, C, and D is based on symptoms, level of lung function, and history of exacerbations.To investigate the abilities of this stratification to predict the clinical course of COPD.Two similar population studies were performed in an area of Copenhagen including 6,628 individuals with COPD.The patients were monitored for an average period of 4.3 years regarding COPD exacerbations, hospital admissions, and mortality. The percentages of individuals experiencing a COPD exacerbation during the first year of observation were 2.2% in group A, 5.8% in group B, 25.1% in group C, and 28.6% in group D. One- and 3-year mortality rates were 0.6 and 3.8%, respectively, in group A, 3.0 and 10.6% in group B, 0.7 and 8.2% in group C, and 3.4 and 20.1% in group D. Groups B and D, characterized by a higher degree of dyspnea than groups A and C, had five to eight times higher mortality from cardiovascular disease and cancer than did groups A and C.The new stratification performs well by identifying individuals at risk of exacerbations. Surprisingly, subgroup B, characterized by more severe dyspnea, had significantly poorer survival than group C, in spite of a higher FEV(1) level. This subgroup warrants special attention, as the poor prognosis could be caused by cardiovascular disease or cancer, requiring additional assessment and treatment.