Chronic bronchitis is not necessary to define COPD.
Li-Cher
LC
Loh
D029481:Bronchitis, Chronic / Q000175:diagnosis*; D003371:Cough / Q000175:diagnosis; D006801:Humans; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis*; D012307:Risk Factors; D012907:Smoking; D013183:Sputum