Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Recurrence
RCT 3-armed trial	213 adults in primary care with any severity of diffuse acute otitis externa on otoscopy	Recurrence 21 to 48 days 21/47 (45%) with acetic acid 14/68 (21%) with dexamethasone–neomycin–polymyxin drops	OR 0.4 95% CI 0.2 to 1.0 OR for antibiotic–corticosteroid versus acetic acid	Moderate effect size	dexamethasone–neomycin–polymyxin