US Pediatric Hospitalizations Complicated by Acute Kidney Injury and Dialysis From 1997 to 2022

There are limited data describing longitudinal trends of acute kidney injury (AKI) and AKI requiring dialysis (AKI-D) in children, adolescents, and young adults in the United States.

To define national trends in pediatric hospitalizations with a diagnosis of AKI or AKI-D between 1997 and 2022.

This retrospective cohort study included data from the Healthcare Cost and Utilization Project Kids' Inpatient Database (KID), a population-based sampling of hospitalizations to pediatric units or children's hospitals, published every 3 years between 1997 and 2022. Hospitalizations for uncomplicated births, among patients with end-stage kidney disease (ESKD), and among patients with history of kidney transplant were excluded. Data were analyzed from June 2025 to February 2026.

AKI was identified using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) for the 1997 to 2012 KID releases and International Statistical Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) for the 2016 to 2022 KID releases. Use of dialysis during hospitalization was assessed using ICD-9-CM and ICD-10-CM procedure codes.

Weighted data were used to estimate national yearly incidence totals and rates of AKI and AKI-D.

The KID included 26 357 519 discharges from 1997 to 2022, 24 344 876 of which were included in the final analysis (estimated mean age, 6.9 [95% CI, 6.8-6.9] years; weighted 46.9% male). Using weighted data, an estimated 253 138 hospitalizations were complicated by AKI overall. The weighted yearly incidence of AKI and AKI-D increased from 6318 cases/y and 981 cases/y, respectively, in 1997 to 63 923 cases/y and 2075 cases/y, respectively, in 2022. AKI hospitalizations per 10 000 discharges increased from 15.7 (95% CI, 14.3-17.1) in 1997 to 168.7 (95% CI, 156.9-181.0) in 2022. Rates of AKI-D increased from 2.4 (95% CI, 2.0-3.0) to 5.5 (95% CI, 4.8-6.2) per 10 000. The mortality rate of hospitalizations with AKI decreased from 1814 to 643 per 10 000 between 2003 and 2022.

In this retrospective study of the KID, the absolute number and rate of pediatric hospitalizations complicated by AKI and AKI-D increased between 1997 to 2022. Factors contributing to the substantial growth may include improved definitions and recognition of AKI, inclusion of a growing number of older and medically complex youth at high risk for AKI, and optimized diagnosis documentation. Given our understanding of the long-term impact of AKI, it is important to assess for preventable causes and to optimize care of those with AKI and AKI-D.