title: Predicting the Risk of Breakthrough Urinary Tract Infections: Primary Vesicoureteral Reflux.
abstract: OBJECTIVE
  We constructed a risk prediction instrument stratifying patients with primary vesicoureteral reflux into groups according to their 2-year probability of breakthrough urinary tract infection.
  
  
  METHODS
  Demographic and clinical information was retrospectively collected in children diagnosed with primary vesicoureteral reflux and followed for 2 years. Bivariate and binary logistic regression analyses were performed to identify factors associated with breakthrough urinary tract infection. The final regression model was used to compute an estimation of the 2-year probability of breakthrough urinary tract infection for each subject. Accuracy of the binary classifier for breakthrough urinary tract infection was evaluated using receiver operator curve analysis. Three distinct risk groups were identified. The model was then validated in a prospective cohort.
  
  
  RESULTS
  A total of 252 bivariate analyses showed that high grade (IV or V) vesicoureteral reflux (OR 9.4, 95% CI 3.8-23.5, p <0.001), presentation after urinary tract infection (OR 5.3, 95% CI 1.1-24.7, p = 0.034) and female gender (OR 2.6, 95% CI 0.097-7.11, p <0.054) were important risk factors for breakthrough urinary tract infection. Subgroup analysis revealed bladder and bowel dysfunction was a significant risk factor more pronounced in low grade (I to III) vesicoureteral reflux (OR 2.8, p = 0.018). The estimation model was applied for prospective validation, which demonstrated predicted vs actual 2-year breakthrough urinary tract infection rates of 19% vs 21%. Stratifying the patients into 3 risk groups based on parameters in the risk model showed 2-year risk for breakthrough urinary tract infection was 8.6%, 26.0% and 62.5% in the low, intermediate and high risk groups, respectively.
  
  
  CONCLUSIONS
  This proposed risk stratification and probability model allows prediction of 2-year risk of patient breakthrough urinary tract infection to better inform parents of possible outcomes and treatment strategies.
authors.affiliation: Department of Urology, Children's Hospital of Orange County, Orange, California.
authors.forename: Guy
authors.initials: G
authors.lastname: Hidas
authors.affiliation: School of Medicine, University of California, Irvine, Irvine, California.
authors.forename: John
authors.initials: J
authors.lastname: Billimek
authors.affiliation: Department of Urology, Children's Hospital of Orange County, Orange, California.
authors.forename: Alexander
authors.initials: A
authors.lastname: Nam
authors.affiliation: Department of Urology, Children's Hospital of Orange County, Orange, California.
authors.forename: Tandis
authors.initials: T
authors.lastname: Soltani
authors.affiliation: Department of Urology, Children's Hospital of Orange County, Orange, California.
authors.forename: Maryellen S
authors.initials: MS
authors.lastname: Kelly
authors.affiliation: Department of Urology, Children's Hospital of Orange County, Orange, California.
authors.forename: Blake
authors.initials: B
authors.lastname: Selby
authors.affiliation: Department of Urology, Children's Hospital of Orange County, Orange, California.
authors.forename: Crystal
authors.initials: C
authors.lastname: Dorgalli
authors.affiliation: Department of Urology, Children's Hospital of Orange County, Orange, California.
authors.forename: Elias
authors.initials: E
authors.lastname: Wehbi
authors.affiliation: Department of Urology, Children's Hospital of Orange County, Orange, California.
authors.forename: Irene
authors.initials: I
authors.lastname: McAleer
authors.affiliation: Department of Urology, Children's Hospital of Orange County, Orange, California.
authors.forename: Gordon
authors.initials: G
authors.lastname: McLorie
authors.affiliation: School of Medicine, University of California, Irvine, Irvine, California.
authors.forename: Sheldon
authors.initials: S
authors.lastname: Greenfield
authors.affiliation: School of Medicine, University of California, Irvine, Irvine, California.
authors.forename: Sherrie H
authors.initials: SH
authors.lastname: Kaplan
authors.affiliation: Department of Urology, Children's Hospital of Orange County, Orange, California. Electronic address: aekhoury@uci.edu.
authors.forename: Antoine E
authors.initials: AE
authors.lastname: Khoury
mesh_terms: D002140:California / Q000453:epidemiology; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D016482:Urinalysis; D014552:Urinary Tract Infections / Q000150:complications* / Q000652:urine; D014718:Vesico-Ureteral Reflux / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology
keywords: risk assessment; urinary tract infections; vesico-ureteral reflux