Flow-Volume Parameters in COPD Related to Extended Measurements of Lung Volume, Diffusion, and Resistance

Figure 4

R5–R20 (a) and Fres (b) measured by impulse oscillometry in controls (healthy smokers) and COPD patients with GOLD stage 1–4. *significant difference compared to healthy smokers, ^†significant difference compared to GOLD1, ^‡significant difference compared to GOLD2, ^#significant difference compared to GOLD3, one symbol flagging 𝑃<0.05, two symbols flagging 𝑃<0.01 and three symbols flagging 𝑃<0.001. Data presented as individual dots together with median with interquartile range.

(a)

(b)