The purpose of this study is to assess whether the risk of serious asthma-related events (asthma-related hospitalizations, endotracheal intubations, and deaths) in adolescents and adults (12 years of age and older) taking inhaled fluticasone propionate/salmeterol combination is the same as those taking inhaled fluticasone propionate alone.

ADVAIR™ and FLOVENT™ are trademarks of the GlaxoSmithKline Group of Companies.

Progress of Enrollment, Updated Annually: This study has been completed and the final clinical study report was submitted to the FDA in January of 2016. This is the final update, as this study is complete.

Inclusion Criteria:

• Provided consent to participate in the study
• Male or female, 12 years of age and older
• Clinical diagnosis of asthma for at least 1 year prior to the randomization
• Clinic PEF of greater than or equal to 50% of predicted normal value
• Subject must be appropriately using one of the treatments for asthma listed in the protocol
• Subject must be able to complete the asthma control questionnaire, daily questions about asthma, and use a DISKUS inhaler
• Subject must have history of at least 1 asthma exacerbation including one of the following in the year prior to randomization:
• requiring treatment with systemic corticosteroids
• an asthma-related hospitalization

Exclusion Criteria:

• History of life threatening asthma defined for this protocol as asthma episode that required intubation and/or was associated with hypercapnea requiring non-invasive ventilatory support
• Concurrent respiratory disease other than asthma
• Current evidence of, or ever been told by a physician that they have chronic bronchitis, emphysema, or chronic obstructive pulmonary disease.
• Exercise induced asthma (as the only asthma-related diagnosis) not requiring daily asthma control medicine
• Presence of a bacterial or viral respiratory infection that is not resolved at randomization
• An asthma exacerbation requiring systemic corticosteriods within 4 weeks of randomization or more than 4 separate exacerbations in the 12 months preceding randomization
• More than 2 hospitalizations for treatment of asthma in the 12 months preceding randomization
• Subject must not meet unstable asthma severity criteria as listed in the protocol
• Potent cytochrome P450 3A4 (CYP3A4) inhibitors within the last 4 weeks (e.g., ritonavir, ketoconazole, itraconzole)
• Pregnancy, breast-feeding or planned pregnancy during the study
• A Child in Care (CiC) is a child who has been placed under the control or protection of an agency, organisation, institution or entity by the courts, the government or a government body, acting in accordance with powers conferred on them by law or regulation.

Patient-level data for this study will be made available through www.clinicalstudydatarequest.com following the timelines and process described on this site.