Relationship between severity of airflow obstruction and GOLD classification in COPD patients

Introduction: According to 2017 update of the Global Initiative for Obstructive Lung Disease (GOLD), strategy patients should be classified into "ABCD" groups based on the symptoms and history of exacerbations. The level of airflow limitation is considered as a poor marker of disease status since it does not correlate with relevant outcomes such as dyspnea, health status, exercise capacity and exacerbations. Aims and objectives: Evaluation of the relationship between the severity of airflow limitation and 2017 “ABCD“ GOLD grading system. Methods: In 255 COPD patients spirometry with bronchodilator reversibility testing (400 mcg salbutamol), COPD assessment test, Modified Medical Research Council Dyspnea Scale were performed. The history of exacerbations was taken into account. Post-bronchodilator FEV1/FVC <70% was used as confirmation of diagnosis of COPD and post-bronchodilator FEV1 was used as assessment of airflow limitation. Results: Out of 255 patients, mean age 69.75 years, 139 (54.5%) were male and 116 (45.5%) were female. Mean post-bronchodilator FEV1 was 1.52L (59.82%), mean FVC was 2.63L (81.72%), mean FEV1/FVC was 57.9%. Patients were casified as GOLD A 16 (6.3%), GOLD B 156 (61.1%), GOLD C 13 (5.1%) and 70 (27.5%) as GOLD D. Mean post-bronchodilator FEV1 in GOLD A was 1.81L, GOLD B 1.60L, GOLD C 1.73L and GOLD D 1.26L. There was a significant association between the post-bronchodilator FEV1 and GOLD groups (r=0.435, p<0.01). Detailed analysis has shown that only post-bronchodilator FEV1 in group D was significantly lower in regards to other groups (p<0.05). Conclusion: Our analysis has shown relationship between disease severity and level of airflow limitation only in group D.