Assessment of urinary tract dilation grading amongst pediatric urologists

Abstract

Introduction: The Urinary Tract Dilation (UTD) system was created to address variability in hydronephrosis grading. It is unknown if or how pediatric urologists are integrating this newer system into practice.

Objective: We sought to evaluate the current use of hydronephrosis grading systems, inter-rater reliability (IRR) for individual systems, and management preferences based on degree of hydronephrosis.

Study design: A survey was emailed to the Societies for Pediatric Urology listserv. Questions addressed familiarity/preference for various grading systems and respondent confidence in interpretation of hydronephrosis. Three clinical vignettes asked respondents to grade hydronephrosis using their system of choice and report further imaging they would obtain. Descriptive statistics were calculated, and IRR was calculated using a linear-weighted modified Fleiss' kappa test.

Results: Response rate was 43% (n = 138). The majority of respondents used Society for Fetal Urology (SFU) (70%) or UTD (19%) systems. Most favored SFU (58%) or UTD (34%) systems for a unified system. Confidence in own interpretation was higher than confidence in radiologists' reads (median 4.4 vs 3.6, p < 0.001). IRR was substantial for UTD (κ0.68 [0.64-0.71]) and moderate for SFU (κ0.60 [0.52-0.76]). There was notable heterogeneity regarding follow-up imaging for cases. There was no difference in requested follow-up studies between SFU and UTD systems, except for fewer voiding cystourethrogram (VCUG) requests for Case 3 with UTD (28% vs 4%, p = 0.02).

Conclusion: Most pediatric urologists still use SFU rather than the UTD system. There was slightly higher IRR with the UTD system. There was substantial variability in follow-up imaging not related to grading system, except with low grade hydronephrosis.

Keywords: Hydronephrosis; Pediatric; Urinary tract dilation (UTD).