Selby 2007.

Methods	Randomized, placebo controlled trial with blinded investigators and patients Intention to treat not performed Induction phase 16 weeks in duration, maintenance phase 104 weeks in duration, trial 156 weeks total; all patients were started on a 16‐week tapering course of prednisolone starting at 40 mg/day
Participants	Patients over age 18 with active CD (CDAI >200) (N = 213 for induction phase and N = 122 for maintenance phase)
Interventions	Randomized to oral clarithromycin 750 mg/day, oral rifabutin 450 mg/ day, oral clofazimine 50 mg/day (n = 102) or oral placebo (three placebo pills were given to placebo group) (n = 111) Maintenance phase: antibiotics (n = 67), placebo (n = 55)
Outcomes	Primary outcomes: The number of patients who had at least 1 relapse by 52, 104 or 156 weeks Secondary outcomes: Clinical remission at week 16 (CDAI ≤ 150), relapses within each study phase, time to first relapse, adverse events, endoscopic remission, need for surgery and quality of life
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	Double blind: matched placebo
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Investigators and participants were blinded to treatment allocation. Investigators were more likely to identify those on active treatment
Incomplete outcome data (attrition bias) All outcomes	Low risk	Ninety‐one subjects were withdrawn during the induction phase (56 placebo group, 35 antibiotic group). Reasons included
Selective reporting (reporting bias)	Low risk	All expected outcomes were reported
Other bias	Low risk	No other apparent sources of bias