Fig. 3From: Salbutamol use in relation to maintenance bronchodilator efficacy in COPD: a prospective subgroup analysis of the EMAX trialMean SABA puffs/day across Weeks 1–24. CI confidence interval, LS least squares, SABA short-acting β2-agonist, SAL salmeterol, UMEC umeclidinium, VI vilanterolBack to article page