Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Recurrence
Systematic review	2153 people aged 6 months to 15 years 6 RCTs in this analysis	Recurrence 214/1113 (19%) with penicillins 214/1040 (21%) with placebo	RR 0.93 95% CI 0.79 to 1.10		Not significant