Sample Size, Power, and Risk of Misclassification in Pediatric Urology Hospital Rankings.

PURPOSE We investigated 2019 and 2020 U.S. News & World Report methodologies of assessing pediatric urology surgical revision rates for distal hypospadias, pyeloplasty, and ureteral reimplantation to evaluate statistical power and misclassification risks. MATERIALS AND METHODS Median annual volumes of distal hypospadias, pyeloplasty, and ureteral reimplantation procedures by hospital from 2016 to 2018 were calculated using the Pediatric Health Information System® database. U.S. News & World Report 2019 and 2020 methodologies were assessed to calculate power required to detect differences between hospitals and risk of hospital misclassifications. RESULTS Median (IQR) annual hospital procedure volume was 72 (43-97) for distal hypospadias procedures, 19 (9-34) for pyeloplasties, and 35 (19-50) for ureteral reimplantations. Based on 2019 methodology, in order to achieve 80% power 764 cases/hospital are required to distinguish between a 1% vs 3% surgical revision rate, 1,500 cases/hospital are required to distinguish between a 3% vs 5% revision rate, and 282 cases/hospital are required to distinguish between a 1% vs 5% revision rate. Based on 2020 methodology, 98.0% of hospitals do not have adequate ureteral reimplantation volume to achieve full points even when reporting no revisions; similarly, 66.0% do not have adequate pyeloplasty volume, and 10.9% do not have adequate distal hypospadias volume. Risks of misclassification exceed 50% in several instances among hospitals reporting distal hypospadias and pyeloplasty revisions using both 2019 and 2020 methodology. CONCLUSIONS Based on median-volume hospitals, current U.S. News & World Report methods for classifying revision rates for distal hypospadias, pyeloplasty, and ureteral reimplantation have insufficient power and are at high risk for misclassification.