UNASSIGNED : In contrast to randomized controlled trials (RCTs), changes in maintenance pharmacotherapy in clinical practice occur without a washout period. The Prospective cohort study for the real-life effectiveness evaluation of glycOpyrronium With indacatERol combination in the management of COPD in Canada (POWER) study evaluated the real-life effectiveness of indacaterol/glycopyrronium (IND/GLY) following a direct switch from a long-acting muscarinic antagonist (LAMA, tiotropium) or long-acting β2-agonist (LABA)/inhaled corticosteroid (ICS) maintenance treatment (salmeterol/fluticasone [SFC]). UNASSIGNED : POWER was a single-cohort, prospective, multicenter, interventional study in which patients with moderate-to-severe COPD, who remained symptomatic on their current treatment of once-daily (od) tiotropium 18 µg or twice-daily (bid) SFC (any dose), were switched to treatment with open-label IND/GLY 110/50 µg od for 16 weeks. Effectiveness end points were change from baseline in trough FEV1, transition dyspnea index (TDI) total scores, and COPD assessment test (CAT) scores at 16 weeks. UNASSIGNED : Trough FEV1 improved by 175 mL at Week 16 in patients who switched to IND/GLY. The change was 176 mL (95% CI: 135-217) when switched from tiotropium and 172 mL (95% CI: 85-258) when switched from SFC fixed-dose combination (FDC). At Week 16, significant improvements were observed in the mean TDI total scores (Δ=2.5) and CAT scores (Δ=-6.5) after the switch to IND/GLY treatment (both P<0.0001). Additionally, IND/GLY was well tolerated in patients with moderate-to-severe COPD, and no safety signal was observed. UNASSIGNED : In clinical practice settings, a direct switch from previous treatment with either tiotropium or SFC to IND/GLY was safe and provided superior clinically significant improvements in lung function and patient-related outcomes in patients with moderate-to-severe COPD. UNASSIGNED : NCT02202616.