How the COVID-19 Pandemic Affected Hospital Antimicrobial Use

Antimicrobial stewardship is an ongoing global effort to use antibiotics sparingly and intentionally to inhibit harmful pathogens from developing resistance. During the COVID-19 pandemic, however, hospitals were understandably more focused on keeping patients from developing severe or fatal disease than they were with limiting antibiotics.

One study, presented at the Society for Healthcare Epidemiology of America Conference 2022 (SHEA), examined antibiotic use patterns at an academic medical center in Richmond, Virginia before and after the COVID-19 pandemic. Additionally, the investigators analyzed the impact of the pandemic on proportional consumption of carbapenems (PoCC).

Carbapenems are highly effective antibiotics, used as the last line of defense against gram-negative bacteria and carefully rationed to prevent pathogens from developing resistance to them as well. In this study, PoCC represented meropenem use relative to use of narrower spectrum anti-pseudomonal agents cefepime and piperacillin-tazobactam.

The study ran from September 2018-August 2021; antimicrobial use data were evaluated using days of therapy (DOT) per 1000 patient days (PD). This timeline included 18 months of data before and after the Richmond academic medical center recorded its first COVID-19 admission in March 2020. The investigators performed mean comparisons with Welch 2-sample t-tests, utilizing Bonferonni’s corrections for multiple comparisons to determine significance with an initial baseline alpha of 0.05.

Presented by Michael Stevens, MD, MPH, the results found significant increases in cefepime, piperacillin-tazobactam, ceftriaxone, and azithromycin usage after the outbreak of COVID-19. There was a significant decrease in the PoCC metric, indicating fewer carbapenems were prescribed during the pandemic. There was no notable change in levofloxacin or meropenem usage.

The investigators concluded that the COVID-19 pandemic was associated with significant changes in their institution’s antimicrobial use patterns. In particular, a statistically significant increase in bacterial community acquired pneumonia-focused antibiotics was noted. They hypothesized that the PoCC decrease was driven by increases in cefepime and piperacillin-tazobactam utilization, while meropenem utilization remained relatively constant. “This highlights the importance of looking at normalized antibiotic consumption data, and not relative use data alone,” the study authors wrote.

The study, “Antimicrobial Use Patterns During the COVID-19 Pandemic at an Academic Medical Center,” was presented on April 12 during the Society for Healthcare Epidemiology of America Conference 2022 (SHEA).