Percentage of culture-positive or PCR-positive sputum samples at stable state and exacerbation in year 1 and year 2 (full cohort, year 1 or year 2). a) Percentage culture-positive for bacteria. b) Percentage PCR-positive for bacteria. c) Percentage PCR-posi... Percentage of culture-positive or PCR-positive sputum samples at stable state and exacerbation in year 1 and year 2 (full cohort, year 1 or year 2). a) Percentage culture-positive for bacteria. b) Percentage PCR-positive for bacteria. c) Percentage PCR-positive for virus. Error bars represent 95% confidence intervals. HRV: human rhinovirus. Tom M.A. Wilkinson et al. ERJ Open Res 2019;5:00248-2018 ©2019 by European Respiratory Society