Lidefelt 1991.

Methods	Study design: parallel RCT Study period: 1986‐1988
Participants	Inclusion criteria Setting/recruitment: emergency department, Sachs' Children's Hospital, Stockholm Country: Sweden Children aged less than 3 years to 12 years with symptoms of a UTI (including frequency, dysuria, and painful micturition) and significant bacteriuria defined as ≥ 105 cfu/mL in 2 separately voided urine samples. Children were required to have had not more than 2 previous UTIs, and the most recent at least 6 months prior to the start of the study. Median age: 5 years Number: treatment group (50); control group (50) Sex (M/F): 13/87 Exclusion criteria Signs of upper tract involvement (temperature < 38.5ºC, absence of loin pain, ESR < 20 mm/h); more than 2 previous UTIs
Interventions	Treatment group Single‐dose TMP 6 mg/kg Control group 5‐day TMP 3 mg/kg/12 h
Outcomes	Persistent bacteriuria (7 days following treatment) Recurrence (> 7 days following treatment)
Notes	Source of funding: Swedish Medical Council, grant number 19X765, and the Swedish Society of Medicine.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	All patients were analysed in groups to which they were assigned
Selective reporting (reporting bias)	Low risk	Planned outcomes were analysed