Unexpectedly high rate of unrecognized acute kidney injury and its trend over the past 14 years

Acute kidney injury (AKI) is a frequent yet often overlooked complication. This study examines the incidence, unrecognized rate, and outcomes of AKI in adults at a large public Chinese hospital from 2010 to 2023. AKI rates were calculated, and outcomes were assessed using follow-up records. Multivariate logistic regression identified risk factors for unrecognized AKI. Among 2,790,540 patients, 5,080 met the AKI criteria, with an overall incidence of 0.18% (0.78% in hospitalizations, 0.05% in outpatients). The unrecognized AKI was 76.3%. In this group, 75% were stage 1, 16.7% stage 2, and 8.3% stage 3. Orthopedics had the highest unrecognized rate (94.5%) and ICUs the lowest (55.77%). Unrecognition of AKI improved from 90.3% in 2010-2011 to 70.2% in 2022-2023. AKI stage progression was linked to poorer survival. Patients with recognized AKI recovered faster than those with unrecognized AKI (8.0 vs. 9.0 days, p < 0.001). The mean follow-up time was 15.8 days, with similar rates at 28 and 90 days post-AKI for both groups. Risk factors for unrecognized AKI included lower AKI stage, baseline creatinine, absence of shock/heart disease/hypertension, and non-nephrology/surgery admissions. Non-nephrology physicians' unfamiliarity with AKI guidelines may contribute to low awareness. Improved early detection and monitoring in high-risk groups are needed.