Research Article

Small Airway Dysfunction in Chronic Bronchitis with Preserved Pulmonary Function

Figure 2

Relationship between FEV1 and IOS parameters. Statistical analyses are performed with Spearman correlation to compare correlation between FEV1 and IOS parameters. Moderate negative correlations were observed in FEV1 and Ax (r = −0.503), Fres (r = −0.449), and R5–R20 (r = −0.452); . By contrast, moderate positively related to FEV1 and X5 (r = 0.477); .