Lieper 2008.

Methods	Randomized, placebo‐controlled trial. Investigators were blinded. Intention to treat Twelve week trial
Participants	Patients age 18 and older with active CD (CDAI > 200 and CRP ≥ 10 mg/L) (N = 41)
Interventions	Patients were randomised to oral clarithromycin 1g daily (n = 19) or oral placebo (n = 22) for 3 months
Outcomes	Primary outcome: Clinical remission (CDAI ≤ 150) or clinical response (fall in CDAI by ≥70 from pre‐treatment level) at 3 months Secondary outcomes: Decrease in van Hees Activity Index, remission as per Harvey Bradshaw Index (≤ 4), improvement in IBDQ and decrease in serum CRP
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomization was carried out by pharmacist independent of the trial. Randomization was performed by a random allocation sequence in blocks of four (two active and two placebo)
Allocation concealment (selection bias)	Low risk	Centralized randomization by pharmacy
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Patients and investigators were blinded to treatment allocation Placebo was identical in size, colour and taste
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Investigators were blinded to randomisation assignments
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	More patients withdrawn from placebo group (7/19 from clarithromycin group, 12/22 of placebo group). More patients had worsening baseline disease in placebo group (4 in treatment group versus 9 in placebo group)
Selective reporting (reporting bias)	Low risk	All expected outcomes were reported
Other bias	Low risk	No other apparent sources of bias