Liern 2011.

Methods	Study design: open‐label parallel RCT Duration of study: not reported Duration of follow‐up: 12 months
Participants	Country: Argentina Setting: single centre Children > 3 years; history of recurrent UTI; toilet trained with no uropathy; normal creatinine; normal renal ultrasound; no antibiotic prophylaxis in past 6 months Number: treatment group (26); control group (24) Mean age (range): 4.6 years (3 to 7 years) Sex (M/F): treatment group (8/18); control group (11/13) Exclusion criteria: pyelonephritis with scarring; VUR; synechiae phimosis; non‐corrected labia minora
Interventions	Treatment group (one of 3 antibiotics) TMP/SMX: 2 mg/kg once/night OR Nitrofurantoin: 2 mg/kg once/night OR Cephalexin: 25 mg/kg once/night Control group No treatment, monthly urine sample tests
Outcomes	Incidence rate of UTI Month of UTI episode Correlation coefficients with predisposing factors No data on adverse events or microbial resistance
Notes	Funding source: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation was performed using the statistical program EPIDAT.3.0, creating two groups
Allocation concealment (selection bias)	Low risk	Allocation was unlikely to be manipulated but treatment arm was known
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient information to permit judgement
Incomplete outcome data (attrition bias) All outcomes	High risk	8/58 lost to follow‐up, no data given
Selective reporting (reporting bias)	High risk	Unclear reporting of repeat symptomatic UTIs
Other bias	Unclear risk	Translation is imperfect and might contribute to uncertainty in details