920. Leveling Up: Evaluation of IV vs. PO Linezolid Utilization and Cost after an Antimicrobial Stewardship Program Revision of IV to PO Conversion Criteria within a Healthcare System

Abstract

Abstract Background Intravenous (IV) to oral (PO) conversion is specifically listed as a pharmacy-based intervention in the CDC’s Core Elements of an Antimicrobial Stewardship Program (ASP). Due to linezolid’s high PO availability and high IV cost, it is used as a marker for pharmacist-driven IV to PO conversion within our healthcare system, which remained low despite the existence of a pharmacist-driven IV to PO protocol. The system ASP implemented an intervention aimed at improving rates of IV to PO conversion of antimicrobials. Methods This retrospective, observational cohort was conducted within a healthcare system composed of 5 adult acute care facilities. The system ASP reviewed and revised the conversion eligibility criteria November 30, 2021 (Table 1). Education was conducted, and a compulsory computerized training module was assigned to every pharmacist in the system. Two follow-up emails reporting results were also sent to the system ASP pharmacy leaders during the post-intervention period, and leaders were encouraged to share results with their departments. The primary objective of this study was to determine if there was a difference in PO linezolid utilization reported as days of therapy per 1000 patient days (DOT/1000 PD) between the pre- and post-intervention periods. Secondary objectives included IV linezolid utilization and cost savings. Results The average DOT/1000 PD for PO linezolid in the pre-intervention period (February-November 2021) was 38.9 compared to 58.8 for the post-intervention period (December 2021-March 2022), p< 0.01 (Figure 1). This reflected an increase in the average percentage of PO use from 42.9 to 62.4% for the pre- and post-intervention periods, respectively (p< 0.01, Figure 2). Inversely, the average DOT/1000 PD for IV linezolid fell from 52.1 to 35.4 in the pre- and post-intervention periods, respectively (p< 0.01). A cost savings analysis revealed a monthly post-intervention savings of $7,091.34 with a projected total annual cost savings of $85,096.09 for the system. Conclusion An ASP intervention that revised criteria for IV to PO conversion, educated pharmacists, and tracked and reported results led to significantly more PO linezolid use and reduced overall cost in a large healthcare system. Disclosures Kerry O. Cleveland, MD, AbbVIe: Honoraria|Merck: Honoraria.