Fig. 3

Moderate-to-severe COPD exacerbation rate during first year of treatment (a), Kaplan–Meier plot (b) and Cox regression analysis (c) of time to first moderate-to-severe COPD exacerbation. Cox proportional hazards model with treatment group, baseline ICS use, baseline COPD severity, smoking status, 1-year exacerbation history and beta-blocker use at baseline as factors. Moderate-to-severe COPD exacerbation rate during first year of treatment interaction P = 0.75; Cox regression analysis interaction P = 0.83. CI confidence interval, COPD chronic obstructive pulmonary disease, HR hazard ratio, ICS inhaled corticosteroids, N total number of patients, n total number of patients experiencing event