In this parallel-group study , 2224 patients ( aged 40 years , Global Initiative for Chronic Obstructive Lung Disease stages III-IV , and one or more moderate COPD exacerbation in the past year ) were randomly assigned ( 1:1:1 ; via interactive voice response or web system ; stratified for smoking status ) to once-daily QVA149 ( fixed-dose combination of indacaterol 110 g and glycopyrronium 50 g ) , glycopyrronium 50 g , or tiotropium 18 g for 64 weeks .