Ferrara 2009.

Methods	Study design: parallel 3 arm RCT Power calculation: no Intention‐to‐treat analysis: no
Participants	Inclusion criteria Setting: ambulatory paediatric nephrology clinic; single centre Country: Italy Girls 3‐14 years attending an ambulatory paediatric nephrology clinic; more than 1 UTI in previous 12 months Number: 84 randomised; 80 analysed Mean age: 7.5 years Exclusion criteria Structural abnormalities; deformities of the urinary tract; impaired kidney function
Interventions	Treatment group Cranberry‐lignoberry concentrate Cranberry concentrate: 50 mL/d for 6 months (97.5 g cranberry concentrate) Ligonberry concentrate: 1.7 g in 50 mL water No sugar additives Lactobacillus GG drink: 100 mL on 5 days each month for 6 months (contains 4 x 107 cfu/100 mL) Control group No treatment
Outcomes	Symptomatic UTI (symptoms being frequency, dysuria, urgency, haematuria, nocturia, fever, back or hip pain and ≥ 108 cfu/L
Notes	Exclusions post randomisation: 0
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random numbers table
Allocation concealment (selection bias)	Unclear risk	No details on how well allocation was concealed
Blinding of participants and personnel (performance bias) All outcomes	High risk	No, girls knew what treatment they were taking
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No details stated
Incomplete outcome data (attrition bias) All outcomes	High risk	Those lost to follow‐up were excluded, no analysis of best and worst case scenarios Losses to follow‐up/withdrawals: 4
Selective reporting (reporting bias)	Low risk	Appropriate outcome
Other bias	Unclear risk	Details on patients are limited, selection bias may be present Source of funding: NS