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

characterize the inter-rater reliabilityof VUR gradeand 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, gradewas assigned according to the standardized international scale. UDR was calculated by dividing the largest ureteral diameter within the false pelvisby the distance between the L1-L3 vertebral bodies. The mean gradeand mean UDR was calculated for each affected kidney. Correlation within each rater was determined using a Pearson’s correlation coefficient. Reliability of VUR gradeand 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 gradewere equally reliable measures, UDR had a tighter confidence interval. For each rater, gradeand UDR were well-correlated (r 1⁄4 0.73-0.84; p <0.0001). In the upper ranges of measurements, gradewas more variable than UDR [Figure]. Using an empirical threshold, the increased variability with grademay lead to significantly more differences in clinical decision-making among physicians (p 1⁄4 0.022). CONCLUSIONS: UDR has good inter-rater reliabilityamong pediatric urologists. There was significantly more clinically relevant variability with gradethan 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.