| Study characteristics |
| Methods |
Double‐blind, placebo‐controlled, multicenter, parallel trial with random allocation of placebo or drug |
| Participants |
Patients were initially screened with a baseline history, physical exam, and flexible sigmoidoscopy or colonoscopy in order to calculate the activity index
Men and non‐pregnant women, at least 18 years of age, with ulcerative colitis of variable extent, from 5 American and 2 Canadian centers and all enrolled between July 1985 and September 1986 (n = 136). Ulceration had to extend at least 20 cm proximal to the anus. Participants had to have a minimum score of 4 measured by DAI (4 subgroups for each of bowel frequency, presence of blood, sigmoidoscopic appearance, and physician's assessment of severity for a maximum score of 12) |
| Interventions |
Random allocation of Rowasa (250 mg tablets) taken as 4 tablets, 4 times a day, for a total of either 4 g/day (n = 47) or 2 g/day (n = 45), and an identical‐appearing placebo (n = 44) for 6 weeks. Compliance was measured by pill counts |
| Outcomes |
Follow‐up was assessed by telephone contact at end of week 1, 2, 4 and 5 and by clinical exam at the ends of weeks 3 and 6. Each clinic visit included flexible sigmoidoscopy and a PGA
Efficacy was assessed by changes in the DAI and PGA. The change in PGA was described as 'much or somewhat improved', 'unchanged', or 'somewhat worse or much worse'. The change in the DAI score was evaluated by end‐of‐study score minus 'baseline' |
| Notes |
Funding support and conflicts of interest were not reported |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Unclear risk |
Not described |
| Allocation concealment (selection bias) |
Low risk |
All assignments to treatment and subsequent assessments of response to treatment were under double‐blind conditions |
| Blinding (performance bias and detection bias)
All outcomes |
Low risk |
Double‐blind: identical placebo |
| Incomplete outcome data (attrition bias)
All outcomes |
Unclear risk |
34% dropout rate, but dropouts appear to be balanced across intervention groups with similar reasons for withdrawal |
| Selective reporting (reporting bias) |
Low risk |
All expected outcomes were reported |
| Other bias |
Low risk |
The study appears to be free of other sources of bias |
