MP55-04 REVISITING THE ROLE OF GENDER ON EARLY DIAGNOSED PRIMARY VESICOURETERAL REFLUX IN INFANTS WITH PRENATAL HYDRONEPHROSIS

characterize the inter-rater reliability of VUR grade and UDR in children with VUR. METHODS: Voiding cystourethrograms (VCUG) of 20 pediatric patients (31 VUR-affected kidneys) were independently reviewed by four pediatric urologists in a blinded fashion. For each renal unit, grade was assigned according to the standardized international scale. UDR was calculated by dividing the largest ureteral diameter within the false pelvis by the distance between the L1-L3 vertebral bodies. The mean grade and mean UDR was calculated for each affected kidney. Correlation within each rater was determined using a Pearson’s correlation coefficient. Reliability of VUR grade and UDR was calculated using intraclass correlation coefficients (ICC) using a two-way ANOVA model interrater agreement. RESULTS: VUR grade (ICC 1⁄4 0.87, 95% CI 1⁄4 0.78-0.93) and UDR (ICC 1⁄4 0.95, 95% CI 1⁄4 0.92-0.97) were reliably measured by four independent raters. While UDR and grade were equally reliable measures, UDR had a tighter confidence interval. For each rater, grade and UDR were well-correlated (r 1⁄4 0.73-0.84; p <0.0001). In the upper ranges of measurements, grade was more variable than UDR [Figure]. Using an empirical threshold, the increased variability with grade may lead to significantly more differences in clinical decision-making among physicians (p 1⁄4 0.022). CONCLUSIONS: UDR has good inter-rater reliability among pediatric urologists. There was significantly more clinically relevant variability with grade than with UDR. Our study demonstrates that UDR is a more objective and reliable measure than grade, and may be a useful adjunct in clinical decision making and categorizing VUR.