Fig. 2

Frequency of COPD exacerbations within the four medication groups. Medication groups are mutually exclusive. TIO/LABA/ICS indicates triple therapy with tiotropium, long-acting beta-agonist/inhaled corticosteroid, TIO indicates tiotropium alone, ICS ± LABA indicates long-acting beta-agonist/inhaled corticosteroid combination therapy, and SAB indicates short-acting bronchodilators alone