Methods |
Multicenter, randomized, double‐blind, double‐dummy, parallel group study (ASCEND I) |
Participants |
Adult patients (aged 18 to 75 years) with mild to moderately active ulcerative colitis confirmed by endoscopy or radiography (N = 301) |
Interventions |
Asacol 2.4 g/day (400 mg tablet; n = 154) or 4.8 g/day of Asacol (800 mg tablet; n = 147) for 6 weeks |
Outcomes |
Primary outcome: treatment success at week 6. Secondary efficacy end points included the proportion of patients who improved from baseline at week 3 and the percentage of patients whose clinical assessment scores (stool frequency, rectal bleeding, sigmoidoscopy scores, PFA scores and PGA scores) improved from baseline scores at weeks 3 and 6, improvement in QOL from baseline to weeks 3 and 6, and time to symptom relief (stool frequency, rectal bleeding or both) and adverse events. Overall improvement or treatment success was defined as either complete remission or a clinical response to therapy. Complete remission was defined as normal stool frequency, no rectal bleeding, a PFA score of 0 (generally healthy), normal endoscopy findings and a PGA score of 0 (quiescent disease activity). A clinical response to therapy was defined as a decrease in the PGA score of at least one point from baseline, plus improvement in at least one other clinical assessment parameter (stool frequency, rectal bleeding, PFA or endoscopy findings) and no worsening in any of the other clinical assessments |
Notes |
|
Risk of bias |
Bias |
Authors' judgement |
Support for judgement |
Random sequence generation (selection bias) |
Low risk |
Permutated block randomization scheme |
Allocation concealment (selection bias) |
Unclear risk |
Not described |
Blinding (performance bias and detection bias)
All outcomes |
Low risk |
Double‐blind, double‐dummy: identical placebos were used. Both investigators and patients were blinded to treatment assignment |
Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
Drop‐outs 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 |