Fig. 2
From: Long-term variability of impulse oscillometry and spirometry in stable COPD and asthma
Relationships between spirometry and IOS parameters in the three subject groups. Spearman correlation coefficients for non-parametric data was used. A %FEV1 and R5 SDbv (GOLD2 rs = − 0.06, P > 0.05; GOLD3 rs = 0.12, P > 0.05; GOLD4 rs = 0.61, P < 0.05), B %FEV1 and R20 SDbv (GOLD2 rs = 0.09, P > 0.05; GOLD3 rs = 0.08, P > 0.05; GOLD4 rs = − 0.04, P > 0.05), C %FEV1 and R5-R20 SDbv (GOLD2 rs = − 0.07, P > 0.05; GOLD3 rs = − 0.08, P > 0.05; GOLD4 rs = 0.42, P > 0.05). %FEV1 = FEV1 as a percentage of predicted. See Table 1 and Table 2 legend for expansion of abbreviations