A Risk Stratification Model to Predict Febrile Urinary Tract Infection After Cessation of Continuous Antibiotic Prophylaxis in Children With Known Vesicoureteral Reflux.

Abstract

This study evaluates the clinical characteristics and predictors of febrile UTI (fUTI) in children with potentially persistent primary vesicoureteral reflux (VUR) who discontinued continuous antibiotic prophylaxis (CAP) without radiographic confirmation of reflux resolution. We hypothesize that many patients can safely discontinue CAP after toilet training and that a nomogram can predict the probability of fUTI after cessation. A retrospective review of an institutional VUR registry (2012-2018) identified children managed with CAP who subsequently discontinued prophylaxis. Patients with secondary VUR, underlying anatomic abnormalities, or inadequate follow-up were excluded. Demographics, clinical characteristics, and outcomes were analyzed. Multivariable Cox proportional hazards modeling identified predictors of postcessation fUTI, and a nomogram was constructed. Model performance was evaluated using the concordance index (C index) and time-dependent AUC (area under the ROC curve). A simplified clinical risk score was developed and validated. Among 876 children with primary VUR, 386 (44%) discontinued CAP without voiding cystourethrogram-confirmed resolution. The median age at cessation was 39 months, with a median follow-up of 44 months. Post cessation, 345 (89%) remained free of fUTI; 41 (11%) developed fUTI. Multivariable analysis identified bowel and bladder dysfunction (HR = 16.1, <i>P</i> < .001) and high-grade VUR (HR = 2.31, <i>P</i> = .02) as independent risk factors for fUTI. The nomogram demonstrated a C index of 0.77 and AUCs of 0.67, 0.80, and 0.77 at 1, 3, and 5 years, respectively. A simplified 3-year risk score stratified patients into low (n = 305), moderate (n = 66), and high (n = 15) risk groups with good discrimination (C index = 0.75, log-rank <i>P</i> < .001). CAP discontinuation is a viable strategy in select children with persistent VUR, particularly those without voiding dysfunction. A predictive nomogram provides a valuable tool for individualized decision-making. Prospective studies are warranted to refine risk stratification and optimize management strategies.