Sandborn 2009.

Study characteristics
Methods	Multicenter, randomized, double‐blind, double‐dummy, active‐controlled trial (ASCEND III)
Participants	Adults (aged 18 to 75 years) with moderately‐active ulcerative colitis that extended proximally beyond 15 cm from the anal verge, as confirmed by flexible sigmoidoscopy or colonoscopy (N = 772)
Interventions	Asacol 2.4 g/day (400 mg tablet; n = 383) or 4.8 g/day of mesalamine (Asacol 800 mg tablet; n = 389) for 6 weeks
Outcomes	Primary outcome: treatment success (overall improvement) at week 6, defined as improvement in the PGA (based on clinical assessments of rectal bleeding, stool frequency, and sigmoidoscopy), with no worsening in any individual clinical assessment Secondary outcomes: clinical remission at weeks 3 and 6; improvement in stool frequency, rectal bleeding, and PFA assessments at weeks 3 and 6; improvement in the sigmoidoscopy with CFT, PGA, and UC‐DAI assessments at week 6; and treatment success in participants with left‐sided disease at week 6
Notes	This study was supported by Procter & Gamble Pharmaceuticals Author conflicts of interest are reported in the manuscript
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	The investigator or designated representative telephoned the Interactive Voice Response System for patient randomization and allocation of study medication once the patient was determined to be eligible for the study
Allocation concealment (selection bias)	Low risk	Interactive Telephone Voice Response System
Blinding (performance bias and detection bias) All outcomes	Low risk	Double‐blind, double‐dummy, identical placebos
Incomplete outcome data (attrition bias) All outcomes	Low risk	Dropouts balanced across intervention groups with similar reasons for withdrawal
Selective reporting (reporting bias)	Low risk	Expected outcomes were reported
Other bias	Low risk	The study appears to be free of other sources of bias