Validation of the GOLD 2017 classification in predicting exacerbations and mortality in COPD patients

Abstract

Background: Multidimensional assessment of chronic obstructive pulmonary disease (COPD) was recommended by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) in 2011 and revised in 2017. The new assessment of COPD (GOLD 2017) has been refined to separate the spirometric assessment (grade 1 to 4) from symptom evaluation (groups A to D). Objectives: We aimed to examine the abilities of the GOLD 2017 classification to predict clinical outcomes including exacerbation and mortality. Methods: Patients with COPD were recruited from Jan. 2006 to Dec. 2012 and follow up for exacerbation and mortality. The predictive abilities of assessment for airflow limitation (spirometric grade 1 to 4) and assessment for symptoms and risk of exacerbations (groups A to D) were examined through logistic regression analysis with receiver operating curve (ROC) estimations and area under the curve (AUC). Results: A total of 471 subjects with COPD were analyzed. The mortality rate was 19.3% during a median follow up period of 2.8 years; the mortality rates for GOLD grade 1 to 4 were 10.6%, 19.4%, 23.0% and 37.1%, respectively. Patients in GOLD groups B, C and D had odds ratios of 1.8 (95% CI, 0.9-3.7), 14.3 (95% CI, 5.6-40.2) and 19.5 (95% CI, 9.8-41.0), respectively for risk of exacerbation relative to group A. The AUC values for the grade 1 to 4 were 0.61 for mortality, and groups A to D were 0.80 for exacerbation. Conclusions: The GOLD 2017 classification performed well by identifying individuals at risk of exacerbations, but its predictive ability for mortality was poor among COPD patients.