 - Forced expiratory volume in 1 second FEV1: Persistent airflow obstruction as indicated by: For subjects 18 years of age at Visit 1, a pre-bronchodilator FEV1 80 predicted recorded at Visit 1, For subjects 12-17 years of age at Visit 1, a pre-bronchodilator FEV1 90 predicted recorded at Visit 1 or FEV1 Forced Vital Capacity FVC ratio 0.8 recorded at Visit 1 