Fig. 2

Plot of bronchodilator-induced change in FEV₁ relative to pre-bronchodilator FEV₁ (∆FEV_1(%Pre−B); top left panel) and relative to predicted normal FEV₁ (∆FEV_1(%PN); top right panel) as a function of pre-bronchodilator FEV₁ in patients with a positive change in FEV₁ (N = 1,040). The horizontal dashed line indicates a 12% change. The bottom left panel is the scatter plot of ∆FEV_1(%Pre−B) vs. ∆FEV_1(%PN) with the diagonal dashed line as the line of identity.