Comparison 1. Antibiotic treatment versus placebo/no treatment.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Recurrence of symptomatic UTI	5		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
1.1 All studies	5	1074	Risk Ratio (M‐H, Random, 95% CI)	0.75 [0.28, 1.98]
2 Recurrence of symptomatic UTI: VUR status	4	912	Risk Ratio (M‐H, Random, 95% CI)	0.64 [0.24, 1.75]
2.1 Children without VUR	4	541	Risk Ratio (M‐H, Random, 95% CI)	0.60 [0.13, 2.74]
2.2 Children with VUR	2	371	Risk Ratio (M‐H, Random, 95% CI)	0.65 [0.39, 1.07]
3 Recurrence of symptomatic UTI: risk of bias fields	5		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
3.1 Adequate allocation concealment studies	2	914	Risk Ratio (M‐H, Random, 95% CI)	0.68 [0.48, 0.95]
3.2 Unclear allocation concealment studies	3	160	Risk Ratio (M‐H, Random, 95% CI)	0.58 [0.05, 6.41]
3.3 Double‐blinded studies	1	576	Risk Ratio (M‐H, Random, 95% CI)	0.65 [0.44, 0.96]
3.4 Open label, unblinded studies	4	498	Risk Ratio (M‐H, Random, 95% CI)	0.72 [0.18, 2.84]
4 Repeat positive urine culture	4		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
4.1 All studies	4	467	Risk Ratio (M‐H, Random, 95% CI)	0.31 [0.08, 1.18]
5 Repeat positive urine culture: risk of bias fields	4		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
5.1 Adequate allocation concealment studies	2	383	Risk Ratio (M‐H, Random, 95% CI)	0.21 [0.02, 2.50]
5.2 Unclear allocation concealment	2	110	Risk Ratio (M‐H, Random, 95% CI)	0.21 [0.00, 32.38]
5.3 Double‐blinded studies	1	45	Risk Ratio (M‐H, Random, 95% CI)	0.05 [0.00, 0.72]
5.4 Open label, unblinded studies	3	448	Risk Ratio (M‐H, Random, 95% CI)	0.48 [0.15, 1.54]
6 Adverse events	2		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
6.1 All adverse events	2	914	Risk Ratio (M‐H, Random, 95% CI)	2.31 [0.03, 170.67]
6.2 Discontinuation of treatment due to adverse events	1	576	Risk Ratio (M‐H, Random, 95% CI)	0.4 [0.13, 1.26]
7 Microbial resistance to prophylactic drug	2	118	Risk Ratio (M‐H, Random, 95% CI)	2.40 [0.62, 9.26]