- If the subject does not meet the above reversibility criteria at Visit 1 then the reversibility assessment may be repeated once within 7 days of Visit 1if either criteria a) or b) are met: >=9% increase in FEV1 between 20 and 60 minutes following 4 inhalations of albuterol/salbutamol aerosol at Visit 1. Documented evidence of a reversibility assessment within 1 year prior to Visit 1 which demonstrated a post-bronchodilator increase in FEV1 of >=12% and >=200 mL.