Figure 5.

Bar graphs showing the association of BDR group with blood eosinophil counts at baseline and decline in FEV₁ after bronchodilator administration over time in participants with GOLD stage 0 disease (ie, normal spirometry findings; n = 1,481) and the entire cohort (n = 2,269). We categorized tobacco-exposed participants with or without COPD based on BDR variability into three groups: consistent BDR when it is present in every visit; inconsistent BDR when it is present at some, but not all, visits; and never BDR when it is not present at any visit. Multivariate linear regression models used BDR group as the independent variable and plasma eosinophil levels at baseline or decline in FEV₁ % predicted after bronchodilator administration over time as the dependent variable. All models included the following covariates: age, sex, race, smoking status and pack-years smoked, and FEV₁ % predicted after bronchodilator administration at first visit, as well as number of visits. Based on these models, we calculated the least square mean (LSM). Pairwise comparisons using Tukey method correction LSM were used. Values in the figures are presented as LSM with 95% CI. ^aP < .05. ^bP < .01. ^cP < .001. ATS-BDR = increase in FEV₁, FVC, or both of ≥ 12% and ≥ 200 mL after bronchodilator administration; BDR = bronchodilator responsiveness; FEV₁-BDR = increase in FEV₁ of ≥ 12% and ≥ 200 mL after bronchodilator administration; FVC-BDR = increase in FVC of ≥ 12% and ≥ 200 mL after bronchodilator administration; GOLD = Global Initiative for Chronic Obstructive Lung Disease.