Risk Stratification for Vancomycin-Associated Acute Kidney Injury in Chinese Adult Inpatients: A Multicenter Retrospective Cohort Study

Purpose: Vancomycin-associated acute kidney injury (VA-AKI) remains a major safety concern during treatment of serious infections. We aimed to identify a clinically relevant vancomycin trough threshold associated with VA-AKI and to define factors associated with renal injury in Chinese adult inpatients. Patients and Methods: We conducted a multicenter retrospective cohort study of 2230 Chinese adult inpatients treated with intravenous vancomycin between 2016 and 2025. VA-AKI was defined according to Kidney Disease: Improving Global Outcomes criteria. Receiver operating characteristic analysis was used to identify the trough threshold associated with VA-AKI, and multivariable logistic regression was performed to assess factors independently associated with VA-AKI. Results: VA-AKI occurred in 493/2230 patients (22.1%). The trough concentration most closely associated with VA-AKI was 15.9 mg/L (AUC 0.64). Compared with troughs 20 mg/L were associated with progressively higher AKI risk. Factors independently associated with VA-AKI included contrast exposure, concomitant piperacillin-tazobactam or cephalosporin therapy, critical illness, treatment duration ≥14 days, cardiac dysfunction, and baseline renal impairment. VA-AKI was also associated with worse outcomes, including higher 60-day mortality (16% vs 4%) and greater dialysis requirement (6% vs 2%). Conclusion: In this large multicenter cohort, VA-AKI occurred in approximately one in five Chinese adult inpatients receiving vancomycin. A vancomycin trough concentration of approximately 15.9 mg/L may serve as a practical threshold for early AKI risk stratification, particularly in clinical settings where AUC-guided monitoring is not routinely available. Closer renal surveillance may be warranted in patients with additional treatment-related or clinical risk factors.