- Severity of Disease: A pre and post-albuterol/salbutamol forced expiratory volume in one second/ forced vital capacity (FEV1/FVC ratio of <0.70 and a post-albuterol/salbutamol FEV1 of >=30% and =<70% of predicted normal values at Visit 1. Predicted values will be based upon the ERS Global Lung Function Initiative