Patients who experience acute kidney injury (AKI) during hospitalization are at a higher risk of readmission and mortality after discharge, suggests a study of almost one million people published online April 27, 2023 in the American Journal of Kidney Diseases.¹ These observations were noted regardless of the presence of chronic kidney disease.

This study retrospectively compared data of 471,176 hospitalized with acute kidney injury (AKI) between January 2007 and September 2020 to examine the outcomes post-hospitalization. Data was sourced from a national claims database. They were compared to matched 471,176 patients hospitalized without AKI. The outcomes selected for the study included all-cause and selected-cause rehospitalizations and mortality 90 and 365 days after index hospitalization.

Analysis of data showed that within 90 days of discharge after the initial hospitalization for AKI, the risk of re-hospitalization due to any cause was increased by 62% with hazard ratio (HR) of 1.62. The risk of all-cause mortality was increased 266% (HR 2.66). The most common reasons for re-hospitalizations were end-stage renal disease (HR 6.21), sepsis (HR 2.62), heart failure (HR 2.81) and pneumonia (HR 1.47), myocardial infarction (HR 1.48). Similar trends were observed after one-year post-discharge, when the odds of re-hospitalization increased by nearly 60% and the risk of mortality increased 2-folds (HR 2.11). These observations were independent of pre-existing renal disease.

These findings highlight the increased risk of adverse events necessitating re-hospitalization in patients with AKI within 3 months and one year after discharge from the index hospitalization. Hence, these patients should be closely monitored after discharge with timely interventions, if required, to prevent such adverse outcomes in the future.

Reference

1. Schulman IH, et al. Readmission and mortality after hospitalization with acute kidney injury. Am J Kidney Dis. 2023 Apr 19:S0272-6386(23)00067-7. doi: 10.1053/j.ajkd.2022.12.008.