Validation of a Prognostic Calculator for Prediction of Early Vesicoureteral Reflux Resolution in Children

Purpose: Treatment of vesicoureteral reflux with observation or surgery is based on a number of clinical variables. We developed a prognostic calculator to predict spontaneous resolution using a computational model. External validation of the computational model is crucial for wide application in clinical practice. Materials and Methods: We reviewed the records of 82 Japanese children with primary vesicoureteral reflux with resolution status known at 2 years after diagnosis. Clinical data were input into the online prognostic calculator. Prognostic accuracy, positive predictive value and negative predictive value were calculated by comparing the predicted and actual clinical results. Clinical parameters were compared to determine the characteristics of cases in which the computational model failed to predict the reflux outcome. Results: The 2-year resolution rate was 49% (40 of 82 patients). Of the cases 42 (51%) were predicted to resolve and 40 (49%) not to resolve by the prognostic calculator. Overall accuracy of the prognostic calculator was 80.5%, with the prediction accurate in 66 patients and inaccurate in 16. Sensitivity for spontaneous resolution was 82.5% and specificity was 78.6%. Positive predictive value was 78.6% and negative predictive value was 82.5%. The ROC for this calculator was 0.793. Mean age in the 16 cases that were inaccurately predicted (4.96 years) was significantly higher than in the 66 that were accurately predicted (3.00, p <0.05). Conclusions: The prognostic calculator was 80.5% accurate at predicting reflux resolution and was more accurate in younger children. This calculator can be widely applied for many patients with reflux.