Epidemiology and disease burden of pediatric congenital anomalies of the kidney and urinary tract: a national cross-sectional study of hospitalized children in China.

Background: Congenital anomalies of the kidney and urinary tract (CAKUT) are among the most prevalent congenital malformations in children and a common cause of chronic kidney disease. There is currently limited documentation of the clinical epidemiology and disease burden of hospitalized CAKUT patients globally. This study reports the clinic-epidemiological characteristics and disease burden of hospitalized CAKUT children in China, and offers critical data to inform the diagnosis, treatment, and prevention of CAKUT.

Methods: From January 2016 to December 2022, hospitalized patients diagnosed with CAKUT were discharged from 33 provincial and municipal hospitals across China. Demographic and clinical data were collected for statistical analysis.

Results: A total of 33,621 children aged 0-18 years were hospitalized with a CAKUT diagnosis, accounting for 0.46% of the total pediatric hospitalizations during the study period. There was a male-to-female ratio of 1.88:1. The CAKUT hospitalization rate demonstrated an increasing trend from 2016 to 2022 (P < 0.001). Regional hospitalization rates were significantly higher in Eastern and Central China compared to Western and Northeastern China (P < 0.001). Most patients were diagnosed with hydronephrosis, with a hospitalization ratio of 1.28% (n = 9359). 18.00% of patients were diagnosed with multiple CAKUT. The incidence of urinary tract infections (UTIs) increased as the number of combined CAKUT conditions rose.

Conclusions: The most common CAKUT subtype is hydronephrosis. The disease spectrum of CAKUT was different in different age groups, which gradually evolved from hydronephrosis to duplex collection system and renal cystic disease. UTI, associated nonurinary congenital anomalies and low birth weight are the warning factors for CAKUT. The cost burden and fatality rate of CAKUT is low. Strengthening the management of CAKUT and appropriate intervention is expected to obtain a good prognosis and improve quality of life.