Risk Factors and Prediction of Acute Kidney Injury in Hospitalized Urology Patients: A Retrospective Cohort Study

Background/Objectives: Acute kidney injury (AKI) is a clinically important complication among hospitalized urology patients. However, data from general urology inpatient populations remain limited. We aimed to assess AKI frequency in a monitored urology inpatient cohort, identify associated predictors, and develop an exploratory admission-based risk stratification model. Methods: We conducted a retrospective observational cohort study of adults admitted to a tertiary urology ward between June 2023 and May 2024 who had at least two serum creatinine measurements during hospitalization. AKI was defined according to Kidney Disease: Improving Global Outcomes (KDIGO) serum creatinine criteria. Demographic, clinical, laboratory, and procedural data were analyzed. Multivariable logistic regression identified factors associated with AKI and was used to construct a reduced exploratory admission-based risk model. Results: Among 196 monitored patients, 67 (34.2%) developed AKI during hospitalization, and 82.1% had KDIGO Stage 1 AKI. Higher admission serum creatinine, hypertension, nephrolithiasis, and ureteral interventions were independently associated with AKI. AKI was also associated with longer hospitalization (6.4 ± 4.2 vs. 5.1 ± 3.2 days, p = 0.044). The reduced exploratory model identified low-, intermediate-, and high-risk groups with progressively increasing AKI incidence (7.7%, 32.3%, and 76%, respectively; AUC = 0.76). Conclusions: In this monitored cohort, AKI was frequent and associated with admission characteristics and prolonged hospitalization. These findings support targeted renal monitoring in higher-risk patients. The admission-based risk model is exploratory and requires validation in prospective multicenter cohorts before clinical implementation.