Patients who experience acute kidney disease (AKD) after acute kidney injury (AKI) have a higher long-term mortality risk compared with those who experience AKD without AKI, according to a Chinese study.

The finding is based on a study of 71,041 inpatients. Of these, AKI developed in 11,518 (16.2%) and AKD developed in 10,203 (14.4%). In addition, 5623 (7.9%) met both AKI and AKD criteria, 4580 (6.4%) experienced AKD without AKI, and 5895 (8.3%) recovered from AKI within 7 days.

Compared with patients who did not have kidney disease, patients with AKI followed by AKD had a significant 4.5-fold increased risk for death in adjusted analyses, Lingyu Xu, MD, of the Affiliated Hospital of Qingdao University in Qingdao, China, and colleagues reported in Clinical Kidney Journal. Those with AKD but no AKI had a significant 2.3-fold increased risk. Patients who had AKI and recovered had a significant 1.2-fold increased risk.

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Mortality risk increased with AKI and AKD stage. Compared with patients with no kidney disease, patients with AKI stage 1, 2, and 3 had a significant 2.1-, 4.3-, and 5.8-fold increased risk for death, respectively, in adjusted analyses. Patients with AKD stage 1, 2, and 3 had a significant 1.6-, 2.9- and 5.1-fold increased risk for death, respectively.

The study also found that AKI and AKD predicted development of de novo chronic kidney disease (CKD). Compared with patients who had no kidney disease, those who had AKI and recovered had a significant 1.6-fold increased risk for de novo CKD. Patients with AKD but no AKI and those with AKD following AKI had a significant 2.2- and 2.5-fold increased risk for de novo CKD, respectively.

Despite its limitations, the study “stands as the pioneering investigation that compares the long-term prognosis of three distinct renal functional trajectories following kidney injury,” the authors wrote. “The criteria for both AKI and AKD demonstrated robust associations with overall mortality and de novo CKD. The AKD criterion provides a more accurate prediction of CKD than the AKI criterion.”

The investigators diagnosed AKI and AKD based on the Acute Disease Quality Initiative Criteria 2017.


Xu L, Li C, Li N, et al. Incidence and prognosis of acute kidney injury and acute kidney disease among 71,041 inpatients. Clin Kidney J. Published online August 25, 2023. doi:10.1093/ckj/sfad208