Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Recurrence
Systematic review	1358 children at increased risk of AOM 13 RCTs in this analysis	Proportion of children with AOM or chronic suppurative otitis media 253/748 (34%) with antibiotics 331/610 (54%) with placebo or no treatment	RR 0.62 95% CI 0.52 to 0.75	Small effect size	antibiotics
Systematic review	1112 children at increased risk of AOM 12 RCTs in this analysis	Number of episodes of otitis media 360 episodes with antibiotics 752 episodes with placebo or no treatment	Incidence rate ratio (IRR) 0.48 95% CI 0.37 to 0.62; see further information on studies for definition of IRR Antibiotics prevented 1.5 episodes of AOM for every 12 months of treatment per child	Effect size not calculated	antibiotics