Evaluating the benefits of antimicrobial prophylaxis to prevent urinary tract infections in children: a systematic review

Background: The recurrence rate for urinary tract infections in children is estimated at between 30% and 40%. The use of low doses of antibiotics as p rophylaxis for recurrent urinary tract infections is common clinical practi ce. However, prolonged antimicrobial therapy has the potential to contribut e to problems of bacterial resistance and antimicrobial side effects. The a im of this review was to systematically examine the available evidence for the effectiveness of this intervention. Methods: We conducted a literature search of 3 electronic databases for the period 1966 to 1999. We also searched bibliographies from conference proce edings and contacted content experts to ensure completeness of our database . Each trial was evaluated on the basis of the following inclusion criteria : target population (children), intervention (antibiotic v. no antibiotic), outcome (number of urinary tract infections) and study design (randomized controlled trial). Quality was assessed for the studies that met these crit eria. Results: Most of the studies identified were case series and cohort studies . Only 6 randomized trials fulfilled the inclusion criteria. All were of lo w quality (median 2, range 0 to 2 [maximum quality score 5]). Three trials dealt with children who had anatomically normal urinary tracts, and three i ncluded children with neurogenic bladder. The rate of infections for patien ts with normal urinary tracts ranged from 0 to 4.0 per 10 patient-years for the treatment groups and from 4.0 to 16.7 for the control groups. The recu rrence rates for patients with neurogenic bladders in 2 trials were 2.9 and 17.1 per 10 patient-years for the treatment groups and 1.5 and 33.0 for th e control groups. Interpretation: The available evidence for using antimicrobial prophylaxis to prevent urinary tract infection in children with normal urinary tracts o r neurogenic bladder is of low quality. This suggests that the magnitude of any benefit should at best be questioned. The surprising lack of data for children with reflux is of concern. Well-designed trials are needed to opti mize the use of antimicrobials in children with recurrent urinary tract inf ection.