| Methods |
Double‐blinded, placebo‐controlled, and centrally‐randomized with stratification in blocks of 10 for each of the 12 centres. Clinical and laboratory examinations were performed at recruitment, after 2 weeks, and at the end of 4 weeks. Endoscopy and biopsy were performed on days 0 and 28. Clinical observations were made on days 0, 14, and 28 |
| Participants |
Outpatients with mild to moderate ulcerative colitis recruited in West Germany between 1984 and 1986 (N = 105) |
| Interventions |
Olsalazine 2 g/day (4 doses of 2 gelatin capsules each; n = 52) or 8 placebo capsules with identical appearance (n = 53). Patients were advised to start with less than 8 pills and reach complete dosage by the third or fourth day and continue for 4 weeks. Compliance was verified by laboratory tests |
| Outcomes |
Endoscopic score was the mean of redness/hyperemia, contact bleeding, spontaneous bleeding and erosions each graded on a 3‐point scale. Clinical status was based on number of stools, presence of blood in stool, stool consistency, and mucous in stool. The clinical score was considered improved when at least 3 of the 4 parameters increased. Occurrence of withdrawals and side effects were also tabulated |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Unclear risk |
Not described |
| Allocation concealment (selection bias) |
Low risk |
Centralized randomization |
| Blinding (performance bias and detection bias)
All outcomes |
Low risk |
Double‐blind: identical placebo capsule |
| 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 |
