Fig. 5From: Respiratory mechanics measured by forced oscillation technique in rheumatoid arthritis-related pulmonary abnormalities: frequency-dependence, heterogeneity and effects of smokingCorrelations between % of the predicted value for forced vital capacity (%FVC) and ΔXrs at 4 Hz (ΔX4) in all cases (n = 69, a) and IP dominant group (n = 23, b)Back to article page