Figure 3 Mean number of severe exacerbations per patient per year in studies by (A) Szafranski et al²⁵ and (B) Calverley et al²⁶ using budesonide/formoterol combinations compared with the single components or placebo. In these trials with different run‐in protocols, neither the inhaled corticosteroid nor the long acting β agonist individually reduced the exacerbation rate. However, when given in combination there was a significant reduction in the exacerbation frequency.