PEDIATRIC UROLOGY

Prediction of Vesicoureteral Reflux after a First Febrile Urinary Tract Infection in Children: Validation of a Clinical Decision Rule
Leroy S, Marc E, Adamsbaum C, Gendrel D, Breart G, Chalumeau M
Clinical Epidemiology Unit, Department of Paediatrics, Saint-Vincent-de-Paul Hospital, AP-HP, Universite Paris V, Paris, France
Arch Dis Child. 2006; 91: 241-4

• Aims: To test the reproducibility of a highly sensitive clinical decision rule proposed to predict vesicoureteral reflux (VUR) after a first febrile urinary tract infection in children. This rule combines clinical (family history of uropathology, male gender, young age), biological (raised C reactive protein), and radiological (urinary tract dilation on renal ultrasound) predictors in a score, and provides 100% sensitivity.
• Methods: A retrospective hospital based cohort study included all children, 1 month to 4 years old, with a first febrile urinary tract infection. The sensitivities and specificities of the rule at the two previously proposed score thresholds (< or =0 and < or =5) to predict respectively, all-grade or grade > or =3 VUR, were calculated.
• Results: A total of 149 children were included. VUR prevalence was 25%. The rule yielded 100% sensitivity and 3% specificity for all-grade VUR, and 93% sensitivity and 13% specificity for grade > or =3 VUR. Some methodological weaknesses explain this lack of reproducibility.
• Conclusions: The reproducibility of the previously proposed decision rule was poor and its potential contribution to clinical management of children with febrile urinary tract infection seems to be modest.
  
  
• Editorial Comment
  The authors attempt to validate a previously proposed decision-rule that can be used to decide when to obtain a VCUG in children who have had a first febrile UTI. This is potentially valuable, as any method of limiting the number of catheterized studies in young children would be beneficial. The proposed decision-rule takes into account the age, gender, family history, C-reactive protein and dilation noted on ultrasound. These are all clinically relevant features of the child presenting with a febrile UTI.
  Unfortunately, the current study population did not support the use of the decision-rule. In order not to miss a positive VCUG, only 3 of the 143 patients would have been excluded. Nineteen could have been excluded if the clinician would be willing to miss 8% of the refluxing patients, including 1 of the 14 with at least grade 3/5 reflux. Moreover, it is well known that VCUGs themselves are only about 80% sensitive. Hence, the reported analysis is likely an overly positive estimate of the benefits of the decision-rule.
  Hanging over this study is the possibility (that this author does not agree with) that diagnosing reflux, is itself of no value. Some have proposed giving temporary prophylactic antibiotics to all patients with febrile UTIs. Others have suggested that prophylactic antibiotics themselves are of no value; if so, why bother diagnosing reflux? In clinical practice, most clinicians still want to diagnose reflux. Therefore, a decision-rule like the one proposed would be of great value. At this time, unfortunately, none exists.

Dr. Barry A. Kogan
Chief and Professor of Urology and Pediatrics
Albany Medical College
Albany, New York, USA