Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Complications
Systematic review	2114 children, aged 12 years and younger 7 RCTs in this analysis	Abnormal tympanometry at 4–6 weeks 438/1063 (41%) with antibiotics 472/1051 (24%) with placebo	RR 0.92 95% CI 0.83 to 1.01		Not significant
Systematic review	809 children, aged 12 years and younger 3 RCTs in this analysis	Abnormal tympanometry at 3 months 96/411 (23%) with antibiotics 96/398 (24%) with placebo	RR 0.97 95% CI 0.76 to 1.24		Not significant
Systematic review	1328 children, aged 6 months–12 years 5 RCTs in this analysis	Abnormal tympanometry 1 month 47% with antibiotics 51% with placebo or no treatment Absolute numbers not reported	RR 0.93 95% CI 0.82 to 1.04		Not significant
Systematic review	1003 chldren, aged 6 months–10 years 4 RCTs in this analysis	Tympanic membrane perforation 9/491 (1.8%) with antibiotics 26/500 (5.2%) with placebo	RR 0.37 95% CI 0.18 to 0.76 P = 0.0069	Moderate effect size	antibiotics
Systematic review	974 children, aged 6 months–15 years 4 RCTs in this analysis	Contralateral otitis (in unilateral cases) 48/453 (10.6%) with antibiotics 85/453 (18.8%) with placebo	RR 0.49 95% CI 0.25 to 0.95 P = 0.034	Moderate effect size	antibiotics