Sutherland 1991.

Methods	Randomized, double‐blind, placebo controlled Intention to treat Sixteen week trial
Participants	N = 105, Patients with active CD with CDAI between 180‐450 (age not mentioned)
Interventions	Patients were randomised to oral metronidazole 20 mg/kg (n = 33) or oral metronidazole 10 mg/kg (n = 30) or oral placebo (n = 36)
Outcomes	Primary outcome: Clinical remission (CDAI < 150) at week 16 Secondary outcomes: Changes in plasma orosomucoid and C reactive protein levels Authors also looked at the effect of metronidazole on disease location
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Both patients and investigators were blinded to the treatment assignment
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Both patients and investigators were blinded to the treatment assignment. No clinical measures were part of outcomes
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Equal discontinuation rate among study groups, metronidazole 10 mg/kg 11/33, metronidazole 20 mg/kg 9/30. But higher attrition rate in placebo group 20/36
Selective reporting (reporting bias)	Low risk	All expected outcomes were reported
Other bias	Low risk	No other apparent sources of bias