Katial 2011

Methods	A 52‐week, randomised, double‐blind, parallel‐group study of fluticasone propionate/salmeterol combination product 250/50 μg twice daily and fluticasone propionate Diskus 250 twice daily in treatment of participants with asthma, at 61 centres in North and South America, Canada, and the Philippines, from May 2007 to May 2009
Participants	Population: 621 adults and adolescents (12+ years) with asthma that was not controlled on ICS at low dose (with or without LABA), or at medium dose without LABA; clinical diagnosis of asthma, defined by the ATS, for ≥ 6 months before screening Baseline characteristics: mean age 38 years; FEV₁ 74% predicted Concomitant ICS used by 100% of participants   Inclusion criteria: participants were required to have treatment with a low to medium dose of ICS or combination ICS/LABA controller medications if the ICS was given at a low dose for ≥ 4 weeks before screening; must have reported being symptomatic while taking controller medication in the 4 weeks before screening Exclusion criteria: life‐threatening asthma in the 12 months before screening; seasonal or exercise‐induced asthma without other manifestations of persistent asthma; concurrent respiratory disease or any other significant concurrent condition/disease; patients were excluded if they had worsening asthma in the 4 weeks before screening, including an emergency room visit, hospitalisation, or use of oral/ parenteral corticosteroid. Concurrent use of medications that could have affected the course of asthma or interacted with study medication was prohibited
Interventions	• Fluticasone propionate and salmeterol 250/50 μg twice daily • Fluticasone 250 μg twice daily Delivery device Diskus
Outcomes	Primary outcome: FEV₁ over a 52‐treatment week period. SAE data fully reported in the published paper and in the GlaxoSmithKline Web report (ADA109055)
Notes	Sponsored by GSK. ClinicalTrials.gov identifier NCT00452699 (identical design to Kerwin 2011)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding (performance bias and detection bias) All outcomes	Low risk	"Double‐blind"
Independent Assessment of causation (detection bias) Asthma‐related events	High risk	Causation of SAEs not independently assessed
Incomplete outcome data (attrition bias) All outcomes	High risk	81/306 on fluticasone propionate/salmeterol and 73/315 on fluticasone propionate withdrew. Of these, 14 and 4, respectively, withdrew due to adverse events or lack of efficacy
Selective reporting (reporting bias)	Low risk	SAE data fully reported