Impact of a monthly antimicrobial stewardship quality assurance tool for elevated vancomycin levels

We sought to determine the value of an audit-and-feedback monitoring method in facilitating meaningful practice changes to improve vancomycin dosing and monitoring.

Retrospective, multicenter, before-and-after implementation observational quality assurance initiative.

The study was conducted in 7 not-for-profit, acute-care hospitals within a health system in southern Florida.

The preimplementation period (September 1, 2019, through August 31, 2020) was compared to the postimplementation period (September 1, 2020, through May 31, 2022). All vancomycin serum-level results were screened for inclusion. The primary end point was the rate of fallout, defined as vancomycin serum level ≥25 µg/mL with acute kidney injury (AKI) and off-protocol dosing and monitoring. Secondary end points included the rate of fallout with respect to AKI severity, rate of vancomycin serum levels ≥25 µg/mL, and average number of serum-level evaluations per unique vancomycin patient.

In total, 27,611 vancomycin levels were analyzed from 13,910 unique patients. There were 2,209 vancomycin serum levels ≥25 µg/mL (8%) among 1,652 unique patients (11.9%). AKI was identified in 379 unique patients (23%) with a vancomycin levels ≥25 µg/mL. In total, 60 fallouts (35.2%) occurred in the 12-month preimplementation period (∼5 per month) and 41 fallouts (19.6%) occurred in the 21-month postimplementation period (∼2 per month; P = .0006). Failure was the most common AKI severity in both periods (risk: 35% vs 24.3%, P = .25; injury: 28.3% vs 19.5%, P = .30; failure: 36.7% vs 56%, P = .053). Overall, the number of evaluations of vancomycin serum levels per unique patient remained consistent throughout both periods (2 vs 2; P = .53).

Implementation of a monthly quality assurance tool for elevated outlier vancomycin levels can improve dosing and monitoring practices resulting in enhanced patient safety.