In this parallel-group study , @ patients ( aged @ 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 ( @:@:@ ; via interactive voice response or web system ; stratified for smoking status ) to once-daily QVA@ ( fixed-dose combination of indacaterol @ g and glycopyrronium @ g ) , glycopyrronium @ g , or tiotropium @ g for @ weeks .