Do long-term antibiotics prevent urinary tract infection in children?

GJ Williams GJ, A Lee, JC Craig

Centre for Kidney Research, Royal Alexandra Hospital for Children, Westmead, Australia.

Children with vesicoureteric reflux, obstructive uropathy and/or recurrent urinary tract infection (UTI) are routinely given long-term antibiotic to prevent further UTI. The aim of this review was to assess whether this widespread practice is effective. Randomised controlled trials were identified from Medline (1966-1998), Embase (1980-1998), Cochrane Controlled Trials Register and references from relevant articles. Two reviewers independently assessed the studies for their quality (allocation concealment, blinding and completeness of follow up) and extracted data. Plausible effect modifiers of observed treatment effect (quality of studies, vesicoureteric reflux and duration of antibiotic treatment) were explored. The relative risk (RR) and 95% confidence intervals (CI) were estimated for individual studies. A random-effects model was used to estimate a summary RR. Four relevant studies with a total of 187 children were identified. The patient populations in the trials were almost exclusively children with recurrent UTI and normal renal tracts. The duration of long-term antibiotic treatment (nitrofurantoin and/or cotrimoxazole) varied from 10 weeks to 12 months. The overall rate of recurrent UTI in the placebo group was 63 (59/94). Compared to placebo/no treatment, antibiotics reduced the risk of recurrent UTI in three studies where allocation concealment was unclear or inadequate (RR=0.36, 95%CI: 0.17-0.76). However, there was no reduction in the risk of recurrent UTI by antibiotics compared to placebo/no treatment when allocation concealment was adequate (RR=0.97, 95%CI: 0.55-1.68). There were no reported antibiotic side effects. The evidence to support the widespread use of antibiotic prophylaxis is weak. Published studies have been poorly designed with biases known to over-estimate the true treatment effect. Well-designed placebo-controlled randomised trials are needed to determine whether long-term antibiotics prevent UTI.

Presented at the Australian and New Zealand Society of Nephrology, Brisbane, March 1999
Presented at the Annual Scientific Meeting of the Royal Australasian College of Physicians, Perth, May 1999

Correspondence
Dr Gabrielle Williams
GabrieW4@chw.edu.au