Djamin RS, et al. - In COPD patients with frequent exacerbations, researchers looked for the features that were predictive of the best response to maintenance therapy with azithromycin in this study, which was part of the COLUMBUS trial-a prospective randomized, double-blind, placebo-controlled study. In the azithromycin group, they observed a significant lower number of exacerbations per patient in relation to baseline blood eosinophil count ≥2.0% vs an eosinophil count < 2.0%, GOLD stage 1–2 vs GOLD stage 4 and GOLD group C vs group D. In relation to a blood eosinophil count ≥2.0% vs an eosinophil count < 2.0% and in GOLD stages 1–2 vs stage 4, significantly lower number of hospitalizations was reported. In COPD patients with frequent exacerbations, the efficacy of azithromycin maintenance treatment was shown in those who were either classified in GOLD stage 1–2 or GOLD C and those with a blood eosinophil count of ≥2.0%.