Computing antimicrobial use/antimicrobial resistance ratios: A novel way to assess inpatient antimicrobial utilization using current National Healthcare Safety Network metrics

Abstract

Background Current methods for benchmarking inpatient antimicrobial use (AU) could benefit from combining AU with antimicrobial resistance (AR) information to provide metrics benchmarked to microbiological data; this may yield more instructive and better risk‐adjusted measurements than AU and AR in isolation. Methods In this retrospective single‐center study, we computed facility‐wide AU/AR ratios from 2019 to 2020 for specific antimicrobial agents and corresponding AR events, and compared median monthly AU/AR ratios between March 2019 through December 2019 (pre‐COVID period) and March 2020 through December 2020 (COVID period). Aggregate AU was expressed as a ratio to aggregate AR events for antimicrobials that typically have activity against the AR organism and are frequently used to treat the AR organism in clinical practice. We also computed AU/AR ratios in our surgical intensive care unit in the pre‐COVID period. Results High‐median facility‐wide monthly AU/AR ratios were observed for intravenous vancomycin/methicillin‐resistant Staphylococcus aureus, with 130.0 in the pre‐COVID period and 121.3 in the COVID period (p =.520). Decreases in facility‐wide median monthly AU/AR ratios were observed between periods for meropenem/ESBL Enterobacterales (20.9 vs. 7.9, p < .001), linezolid/vancomycin‐resistant Enterococcus (48.5 vs. 15.8, p =.004), and daptomycin/vancomycin‐resistant Enterococcus (32.2 vs. 4.8, p = .002). Increases in facility‐wide median monthly AU/AR ratios were observed between periods for ceftazidime‐avibactam/carbapenem‐resistant Enterobacterales (0.0 vs. 3.2, p = .020) and ceftazidime‐avibactam/multidrug‐resistant Pseudomonas aeruginosa (0.0 vs. 4.0, p = .017). The AU/AR ratio for intravenous vancomycin/methicillin‐resistant S. aureus in the surgical intensive care unit was 191.5 in the pre‐COVID period. Conclusions AU/AR ratios may be used to supplement current AU and AR metrics. Future directions should include the development of more AU metrics benchmarked to microbiological information. AU metrics more specific to transplant infectious diseases should be developed.

Comparative antimicrobial use in coronavirus disease 2019 (COVID-19) and non–COVID-19 inpatients from 2019 to 2020: A multicenter ecological study

“…Empiric administration of vancomycin was likely driven by the same factors because prescribers often overestimate the occurrence of methicillin-resistant Staphylococcus aureus as a causative agent for infection in inpatient settings. 24 The administration of ceftriaxone and azithromycin to COVID-19 patients was likely driven by empiric coverage for community-acquired pneumonia. 11 Ceftriaxone and azithromycin administration was especially high in March 2020 in the setting of constrained testing capacity for SARS-CoV-2 at the onset of the pandemic, 25 likely leading healthcare providers to cover for bacterial infection given diagnostic uncertainty.…”

The CDC antimicrobial use measure is not ready for public reporting or value-based programs

“…This analysis may be possible with the requirement of submission to the Antimicrobial Resistance Option, and preliminary investigations into utilization of antimicrobial resistance data have been done. 8 However, any pay-for-performance initiative designed prior to its inclusion would be premature.…”