Methods	Parallel-group, multicentre study (95 centres in North America) Jadad quality score = 4
Participants	Moderately severe asthmatic adults % ELIGIBLE OF SCREENED POPULATION: Not reported % RUN-IN PARTICIPANTS RANDOMISED: Not reported RANDOMISED: 636 (FP/SAL: 321; FP: 315) WITHDRAWALS: FP/SAL: 32; FP: 44 AGE mean: 39 GENDER (% male): 38 SEVERITY: Moderate BASELINE % PREDICTED FEV1: 80.4 BASELINE DOSE OF ICS: Not reported ASTHMA DURATION: Not reported ATOPY (%): Not reported ELIGIBILITY CRITERIA: 12 years or older - medium dose of ICS for at least 30 days prior to randomisation (dose not specified); ATS defined asthma for at least 6 months; FEV1 65% to 95% predicted; >= 12% reversibility post-SABA EXCLUSION CRITERIA: Life-threatening asthma/hospitalisation within 3 months of study entry; OCS within 30 days of screening OR 2 courses within 90 days; other concurrent respiratory disease; more than a 10 pack-year history of smoking
Interventions	LABA + ICS versus INCREASED dose ICS OUTCOMES TIMING: 12, 24 weeks (trial extension) RUN-IN: Not reported DOSE OF ICS DURING RUN-IN: Not reported INTERVENTION PERIOD: 12 weeks TEST GROUP: Combination fluticasone and salmeterol 100/50 mcg bid CONTROL GROUP: Fluticasone 250 mcg bid DEVICE: Diskus NUMBER OF DEVICES: 1 COMPLIANCE: Not assessed CO-TREATMENT: prn SABA
Outcomes	PULMONARY FUNCTION TEST: am PEF; FEV1 SYMPTOM SCORES: % symptom-free days FUNCTIONAL STATUS: Rescue medication usage INFLAMMATORY MARKERS: Not reported ADVERSE EFFECTS: Reported WITHDRAWALS: Due to lack of efficacy*, other reasons reported Primary outcome measure*
Notes	Full unpublished data set available from http://www.ctr.gsk.co.uk Source of funding: GSK Confirmation of methodology and data: Obtained for methods, not for data User defined number: 1000
Risk of bias
Item	Authors’ judgement	Description
Adequate sequence generation?	Yes	See Appendix 3
Allocation concealment?	Yes	See Appendix 3
Blinding? All outcomes	Yes	Identical inhaler devices used
Incomplete outcome data addressed? All outcomes	Unclear	“Efficacy and safety analyses were performed on the intent-to-treat (ITT) population which consisted of all subjects who were randomised to study drug regardless of enrolment date.”
Free of selective reporting?	Yes	OCS-treated exacerbations available on request from GSK