A Reanalysis of the RIVUR Trial Using a Risk Classification System

Abstract

Purpose: The RIVUR (Randomized Intervention for Children with Vesicoureteral Reflux) trial showed a 50% decrease in the risk of urinary tract infection recurrence in children with reflux receiving continuous antibiotic prophylaxis. We reanalyzed the RIVUR data with the purpose of using a risk classification system to identify children who are more likely to benefit from continuous antibiotic prophylaxis.

Materials and methods: Data from 607 children enrolled in the RIVUR trial were obtained from the National Institute of Diabetes and Digestive and Kidney Diseases Central Repository and analyzed. We stratified these children into low and high risk categories. The proportion of children and risk of urinary tract infection recurrence in the stratified treatment groups were compared.

Results: Of the children 385 (63.9%) were stratified into the low risk and 217 (36.1%) into the high risk category. The proportions of children with urinary tract infection recurrence were not significantly different in the low risk category between the placebo and continuous antibiotic prophylaxis groups (p = 0.151), while urinary tract infection recurrence was significantly higher in the placebo group (31.5% vs 11.4%, p = 0.001) for high risk children. Furthermore, high risk children on placebo had a 3.7-fold increased risk of urinary tract infection recurrence during 2 years of followup compared to those on continuous antibiotic prophylaxis.

Conclusions: Although the RIVUR trial concluded that children with vesicoureteral reflux benefit from continuous antibiotic prophylaxis, our reanalysis of the data demonstrates that high risk children benefit more, with a number needed to treat of 5 compared to 18 in low risk children. The clinical implications of these findings suggest a need to refine current indications for continuous antibiotic prophylaxis in children with reflux, supporting a shift toward a "selective" risk based approach for management.

Keywords: anti-bacterial agents; infection; risk; vesico-ureteral reflux.