Clinical impact of the lower limit of normal of FEV1/FVC on detecting chronic obstructive pulmonary disease: A follow-up study based on cross-sectional data
Keywords: COPD; LLN; GOLD 0.7fixed ratio; Lung function; CPET; Diagnosis; COPD; Chronic Obstructive Pulmonary Disease; LLN; Lower Limit of Normal; GOLD; Global initiative for chronic obstructive pulmonary disease; GIRD/SKLRD; Guangzhou Institute of Respiratory Dise