Chronic bronchitis in COPD patients is associated with increased risk of exacerbations: a cross-sectional multicentre study

CB prevalence in GOLD stage 2-4 COPD patients is high. CB is related to current tobacco smoking, and prevalence increases with COPD severity and duration, emphysema and age. CB could be the hallmark of a subtype of COPD easy to identify in clinical practice, associated with increased disease severity and increased risk of exacerbation.