LAUSR

PURPOSE Chronic kidney disease affects 25-50% of patients with spina bifida. Guidelines recommend kidney function surveillance in these patients, but practice patterns are unknown. Variations in kidney function surveillance were assessed across patients with spina bifida, with the hypothesis that the treating clinic and spina bifida type would be associated with kidney function surveillance. MATERIALS AND METHODS A retrospective cohort study was conducted from 2013-2018 within the National Spina Bifida Patient Registry in the United States. Follow-up was anchored at the 2013 visit. Participants with either an outcome event within 2 years of follow-up or >2 years of follow-up without an outcome event were included. Primary outcome was kidney function surveillance, defined as at least one renal ultrasound and serum creatinine within 2 years of follow-up. Primary exposures were clinic and spina bifida type, which were analyzed with covariates including sociodemographic and clinical characteristics in logistic regression models for their association with the outcome. Sensitivity analyses were performed using different kidney function surveillance definitions. RESULTS Of 8351 total patients, 5445 were included, with median 3.0 years' follow-up. Across 23 treating clinics, kidney function surveillance rates averaged 62% (range 6-100%). In multivariable models, kidney function surveillance was associated with clinic, younger age, functional lesion level, non-ambulatory status, and prior bladder augmentation. Treating clinic remained a significant predictor of kidney function surveillance in all sensitivity analyses. CONCLUSIONS Within the National Spina Bifida Patient Registry, wide variation exists in practice of kidney function surveillance across treating clinics, despite adjustment for key patient characteristics.