Short-Course Therapy for Pediatric Urinary Tract Infections

Summary The SCOUT study is a multicenter, placebo-controlled, double-blind randomized controlled trial conducted to evaluate if a shorter 5-day course of antibiotics is non-inferior to a standard 10-day course of antibiotics in children with urinary tract infection (UTI) [1]. The eligible population included children aged 2 months to 10 years who were being treated for UTI with one of the five chosen antibiotics (amoxicillin-clavulanate, cefixime, cefdinir, cephalexin, or trimethoprim-sulfamethoxazole) and have become afebrile and free of symptoms of UTI after 5 days of therapy. At this time point, the eligible children were randomized to either the short-course arm, in which antibiotics were replaced by a matching placebo or the standard-course arm, in which antibiotics were continued. The study drugs (placebo or antibiotics) were continued to complete 10 days of therapy. The study’s primary outcome was the recurrence of symptomatic UTI between two hospital visits - first on day 6 i.e., at the time of randomization, and second between days 11 and 14. A definition with high specificity was used to identify the primary outcome and included three criteria: symptoms, pyuria, and positive urine culture. Secondary outcomes included the individual components of the primary outcome, and UTI between days 11–14 and days 38–44. The study also reported the adverse effects of the drugs and the incidence of gastrointestinal colonization with resistant organisms. The sample size was calculated for investigating the non-inferiority of the shorter antibiotic course. The study was powered to detect a non-inferiority margin of 5%. This meant that if the baseline incidence of treatment failure with the use of a standard course of antibiotics was 5%, investigators were willing to accept a treatment failure rate of 10% in the shorter antibiotic course to consider it as a ‘clinically’ non-inferior therapy. The primary analysis was conducted following the intention-to-treat (ITT) principle. The primary outcome was observed in 14 (4.2%) children in the short-course group and 2 (0.6%) children in the standard-course group. The upper margin of the confidence interval of the risk difference was 5.5%. As this was more than the preset non-inferiority margin of 5%, the non-inferiority of the short-course therapy could not be proven. Children randomized to the short-course therapy were also more likely to have asymptomatic bacteriuria and a positive urine culture. The two study groups had similar rates of adverse events and antimicrobial resistance of stool flora. The authors concluded that although the non-inferiority could not be proven, given the low incidence of failure (i.e., recurrence of symptomatic UTI) with the short-course therapy, the latter can be a reasonable option in children with UTI who show improvement after 5 days of antibiotics.