Fig. 2From: Low human beta-defensin-2 levels in the sputum of COPD patients are associated with the risk of exacerbationsAssociation of pathogen colonization status at baseline (Only Bact+, Only Vir+, Both+, and Both-) with the frequency of exacerbations in patients. Patients were grouped according to the times of exacerbations during the 2-year study, and the number (A) or proportion (B) of patients who were positive or negative for bacteria or viruses was calculatedBack to article page