Sood 2000.

Methods	Randomized controlled trial Single (patient) blind placebo controlled Induction period included (steroid tapering) Study duration 12 months
Participants	Diagnosis of ulcerative colitis Relapse within 2 months of steroid withdrawal following successful induction of remission n = 50
Interventions	Azathioprine 2.0 mg/kg/d for 1 year Compared to placebo Co‐medication induction period: i.v. hydrocortisone 400 mg/day, sulfasalazine 6‐8 g/day, ciprofloxacin and metronidazole for 5 days Taper off of steroids to 1 mg/kg/day P.O., then by 10 mg every 10 days to 20 mg, then by 5 mg every 10 days Co‐medication maintenance: sulfasalazine 6 g/day
Outcomes	Main: Complete or partial remission at 1 year (after successful induction) Secondary: adverse events
Notes	The author was approached for clarification of the randomization and allocation concealment; no response was received
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "pseudorandom numbers ranging from 0‐1 generated by a scientific calculator"
Allocation concealment (selection bias)	Unclear risk	Not described in the published study
Blinding of outcome assessment (detection bias) All outcomes	High risk	Quote: "single‐blind" Quote: "identical matched placebo drugs" Quote: "drugs were provided by a single coordinator (VK) to the patients in identical blister packs" Quote: "The treating physician was aware of the drug treatment"
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Quote: "Five patients...were excluded because of noncompliance and violation of treatment protocol" It is difficult to determine how these were dealt with in the analysis
Selective reporting (reporting bias)	Low risk	All outcome were reported
Other bias	Low risk	Nothing of note