Comparison of the clinical characteristics and comprehensive assessments of the 2011 and 2017 GOLD classifications for patients with COPD in China

Objective: Compared with the 2011 Global Initiative for Chronic Obstructive Lung Disease (GOLD), there have been significant changes in the 2017 GOLD classification. The purpose of this study was to analyze the changes in clinical characteristics of the new A-B-C-D system and to explore its role in comprehensive assessment of COPD. Subjects and methods: A total of 631 stable COPD patients were included in a cross-sectional survey. Data collected included baseline data and pulmonary function testing results, respiratory muscle strength, symptoms and quality of life, exercise capacity, nutritional status, and anxiety and depression as a comprehensive assessment. Based on the 2011 GOLD and 2017 GOLD classifications, patients were divided into Groups A(1)-D-1 and Groups A(2)-D-2, respectively. Results: In the 2011 GOLD, 64 subjects in Group C-1 were reclassified into Group A(2) (41.6%), while 77 subjects in Group D-1 were reclassified into Group B-2 (27.1%). The old and new grading systems were somewhat consistent (Cohen's kappa=0.6963, P<0.001). Lung function was lower, while the body mass index, airflow obstruction, dyspnea, and exercise capacity index (BODE index) was higher in Group A(2) than in Group A(1) (P<0.001). In Group B-2, lung function, 6-minute walking distance (6MWD), and respiratory muscle strength were significantly lower than in Group B-1 (P<0.001), while the BODE index (P<0.001) was higher. In comprehensive assessment, subjects in Groups B-2 and D-2 had significantly lower lung function, 6MWD, respiratory muscle strength, quality of life, higher symptom scores, and BODE index than subjects in Group A(2) (P<0.001). The differences between Group A(2) and C-2 were small. Conclusion: Compared with the 2011 GOLD, the 2017 GOLD reclassified more patients into Groups A and B, those with significantly worse lung function and higher BODE index. In the comprehensive assessment of the new classification, Groups B and D may have greater disease severity. However, the effectiveness of the new grading system in predicting patient prognosis, and its guidance on the use of drugs, remains to be explored in future studies.