Lambert 1986.

Methods	Randomised, placebo‐controlled trial (patients who failed to respond at 2 weeks crossed over to alternative treatment)
Participants	60 children aged from 2 to 15 years completed the study. Participants were recruited from the otolaryngology clinic. Effusion present for at least 2 months Diagnosis: 1A, 2C 72% bilateral
Interventions	Antibiotic (amoxycillin) plus prednisone 1.5 mg/kg daily in tapering doses (n = 32) versus antibiotic plus placebo (n = 28) for 2 weeks
Outcomes	Resolution defined by otoscopy and tympanometry Improvement defined by better hearing on pure tone audiometry Not clear if resolution referred to clearing of both ears when bilateral OME at entry Measured 7 to 10 days after completion of treatment Audiometry data used ear as unit of analysis and present outcomes as ears resolving with each treatment
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method of sequence generation not stated
Allocation concealment (selection bias)	Unclear risk	Although the study was (double‐blind) placebo‐controlled it is not clear if the person enrolling patients was blind to treatment allocation and control truly indistinguishable from intervention Quote: "placebo, which consisted of a cherry‐flavoured lactose syrup, was given in the same manner"
Blinding (performance bias and detection bias) All outcomes	Low risk	Unclear if outcome assessors were blind, but study reported as double‐blind
Incomplete outcome data (attrition bias) < 1 month	Unclear risk	60 participants included in analysis, but not clear if more were randomised
Incomplete outcome data (attrition bias) 1 to 6 months	Unclear risk	—
Selective reporting (reporting bias)	Unclear risk	Poor reporting of results
Other bias	Low risk	—