title: Vesicoureteral Reflux Index: 2-Institution Analysis and Validation.
abstract: OBJECTIVE
  The vesicoureteral reflux index is a novel tool designed to predict spontaneous reflux resolution in infants younger than 2 years. We performed a multi-institutional validation study to confirm the discriminatory power of the vesicoureteral reflux index to predict the vesicoureteral reflux resolution rate in young children.
  
  
  METHODS
  We identified patients diagnosed with primary vesicoureteral reflux before age 24 months who had 2 or more voiding cystourethrograms available. Demographics, vesicoureteral reflux grade and timing, ureteral anomalies and radiographic outcomes were evaluated. The C-index was estimated for time to event model assessment.
  
  
  RESULTS
  A total of 219 girls and 150 boys met study inclusion criteria. Mean ± SD age at diagnosis was 4.7 ± 4.9 months. Of the patients 101 (27.4%) had early to mid filling, 214 (58%) had late filling and 54 (14.6%) had voiding only vesicoureteral reflux. High grade reflux was present in 87 patients (23.6%) and ureteral anomalies were observed in 50 (13.6%). A vesicoureteral reflux index of 1, 2, 3, 4 and 5 or greater showed an improvement/resolution rate of 88.2%, 77.3%, 62.3%, 32.1% and 14.3%, respectively. On time to event analysis children with filling phase vesicoureteral reflux (p <0.001), grade 4-5 reflux (p <0.001) and ureteral anomalies (p = 0.003) had significantly longer median time to resolution. Median time to spontaneous resolution was 12.6, 12.7, 15.1, 25.6 and 31 months or greater for a vesicoureteral reflux index of 1, 2, 3, 4 and 5 or greater, respectively (C-index 0.305, 95% CI 0.252-0.357). During the study period 65 patients (17.6%) underwent surgical intervention.
  
  
  CONCLUSIONS
  The vesicoureteral reflux index is a simple tool that reliably predicts significant improvement and spontaneous resolution of primary reflux in patients diagnosed at younger than 2 years. The index provides valuable prognostic information, facilitating individualized patient care.
authors: Department of Urology and Pediatrics, University of Iowa Hospitals and Clinics, Iowa City, Iowa.
authors: Angela M
authors: AM
authors: Arlen
authors: Department of Pediatric Urology, Children's Healthcare of Atlanta, Emory University School of Medicine, Atlanta, Georgia.
authors: Michael
authors: M
authors: Garcia-Roig
authors: Department of Pediatric Urology, Children's Healthcare of Atlanta, Emory University School of Medicine, Atlanta, Georgia.
authors: Aaron D
authors: AD
authors: Weiss
authors: Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University School of Medicine, Atlanta, Georgia.
authors: Traci
authors: T
authors: Leong
authors: Department of Urology and Pediatrics, University of Iowa Hospitals and Clinics, Iowa City, Iowa.
authors: Christopher S
authors: CS
authors: Cooper
authors: Department of Pediatric Urology, Children's Healthcare of Atlanta, Emory University School of Medicine, Atlanta, Georgia. Electronic address: akirschmd@gmail.com.
authors: Andrew J
authors: AJ
authors: Kirsch
mesh_terms: D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011379:Prognosis; D012075:Remission, Spontaneous; D012189:Retrospective Studies; D014718:Vesico-Ureteral Reflux / Q000175:diagnosis*
keywords: decision support techniques; kidney; remission; spontaneous; ureter; vesico-ureteral reflux