Vancomycin Safety Monitoring Using an Electronic Health Record Database

BACKGROUND: Measures of antimicrobial safety are important for antimicrobial stewardship programs (ASP) and health-system quality. Vancomycin (VAN) is a frequently used antibiotic in the inpatient setting, and its most common serious adverse effect, acute kidney injury (AKI), can be identified reliably from laboratory data within the electronic health record (EHR). Our ASP reviews monthly AKI in VAN-treated patients, excluding prior kidney disease, as a metric for harm. EHR-derived rates of AKI were selected as a metric for health system quality and safety reporting. METHODS: IRB-exempt cross-sectional study using aggregate data in a 4-hospital health system. We used interrupted time series methods to compare AKI before and after implementation of a simplified vancomycin dosing strategy: pre- 11/15 to 4/16, post- 5/16 to 4/17. Primary endpoint: number of patients per month with AKI, defined as an increase in serum creatinine of at least 0.5 mg/dL or 50% of baseline. Denominator: number of vancomycin days of therapy (DOT) per 1000-patient-days. Rate of AKI in the total hospitalized population was used for context. RESULTS: There were 10453 orders for vancomycin across the study period (3634 pre, 6819 post). The average rate of AKI in patients receiving vancomycin was 10.6% pre, 8.9% post, while AKI rate in the total hospitalized population was 7.26% across the study period. After implementation of simplified VAN dosing policy, AKI per VAN DOT/1000 patient-days decreased from 0.46 to 0.40 (Figure 1). The median (IQR) vancomycin levels were: 16.7 μg/mL (16.2–17.1) pre, 15.8 (15.3–16.6) post. CONCLUSION: EHR-based measures of antibiotic-related harm are promising tool for ASPs to measure impact patient outcomes. We observed reduced AKI in VAN treated patients, improving safety with a simplified VAN dosing strategy. DISCLOSURES: S. L. Davis, Allergan: Grant Investigator and Scientific Advisor, Consulting fee and Research grant; Merck: Grant Investigator and Scientific Advisor, Consulting fee and Research grant