We aimed to determine whether benchmarking antimicrobial use (AU) to antimicrobial resistance (AR) using select AU/AR ratios is more informative than AU metrics in isolation.

We retrospectively measured AU (antimicrobial therapy days per 1,000 days present) and AU/AR ratios (specific antimicrobial therapy days per corresponding AR event) in two hospitals during 2020 through 2022. We then had antimicrobial stewardship committee members evaluate each AU and corresponding AU/AR value and indicate whether they believed it represented potential overuse, appropriate use, or potential underuse of the antimicrobials, or whether they could not provide an assessment.

Two acute-care hospitals.

Hospitalized patients.

In semi-annual facility-wide analyses, echinocandins had a median AU/AR ratio of 658.5 therapy days per fluconazole-resistant Candida event in Hospital A, IV vancomycin had a median AU/AR ratio of 114.9 and 108.2 therapy days per methicillin-resistant Staphylococcus aureus event in Hospital A and B, respectively, and linezolid had a median AU/AR ratio of 33.8 and 88.0 therapy days per vancomycin-resistant Enterococcus event in Hospital A and B, respectively. When AU and AU/AR values were evaluated by stewardship committees, more respondents were able to assess antimicrobial use based on AU/AR values compared to AU values. Based on AU/AR ratios, most respondents identified potential overuse of echinocandins and IV vancomycin in Hospital A, and potential overuse of linezolid and IV vancomycin in Hospital B.

Select AU/AR ratios provided informative metrics to antimicrobial stewardship personnel, which can be used to motivate audits of antimicrobial administration to determine appropriateness.

To evaluate postoperative outcomes among patients undergoing colon surgery who receive perioperative prophylaxis with ertapenem compared to other antibiotic regimens.

Multicenter retrospective cohort study among adults undergoing colon surgery in seven hospitals across three health systems from 1/1/2010 to 9/1/2015.

Generalized linear mixed logistic regression models were applied to assess differential odds of select outcomes among patients who received perioperative prophylaxis with ertapenem compared to other regimens. Postoperative outcomes of interest included surgical site infection (SSI), Clostridioides difficile infection (CDI) and clinical culture positivity for carbapenem-resistant Enterobacteraciae (CRE). Inverse probability weights were applied to account for differing covariate distributions across ertapenem and non-ertapenem groups.

A total of 2,109 patients were included for analysis. The odds of postoperative SSI was 1.56 times higher among individuals who received ertapenem than among those receiving other perioperative antimicrobial prophylaxis regimens in our cohort (46 [3.5%] vs 20 [2.5%]; IPW-weighted OR 1.56, [95% CI, 1.08–2.26], P = .02). No statistically significant differences in odds of postoperative CDI (24 [1.8%] vs 16 [2.0%]; IPW-weighted OR 1.07 [95% CI, .68–1.68], P = .78) were observed between patients who received ertapenem prophylaxis compared to other regimens. Clinical CRE culture positivity was rare in both groups (.2%–.5%) and did not differ statistically.

Ertapenem use for perioperative prophylaxis was associated with increased odds of SSI among patients undergoing colon surgery in our study population, though no differences in CDI or clinical CRE culture positivity were identified. Further study and replication of these findings are needed.

We sought to determine whether increased antimicrobial use (AU) at the onset of the coronavirus disease 2019 (COVID-19) pandemic was driven by greater AU in COVID-19 patients only, or whether AU also increased in non–COVID-19 patients.

In this retrospective observational ecological study from 2019 to 2020, we stratified inpatients by COVID-19 status and determined relative percentage differences in median monthly AU in COVID-19 patients versus non–COVID-19 patients during the COVID-19 period (March–December 2020) and the pre–COVID-19 period (March–December 2019). We also determined relative percentage differences in median monthly AU in non–COVID-19 patients during the COVID-19 period versus the pre–COVID-19 period. Statistical significance was assessed using Wilcoxon signed-rank tests.

The study was conducted in 3 acute-care hospitals in Chicago, Illinois.

Hospitalized patients.

Facility-wide AU for broad-spectrum antibacterial agents predominantly used for hospital-onset infections was significantly greater in COVID-19 patients versus non–COVID-19 patients during the COVID-19 period (with relative increases of 73%, 66%, and 91% for hospitals A, B, and C, respectively), and during the pre–COVID-19 period (with relative increases of 52%, 64%, and 66% for hospitals A, B, and C, respectively). In contrast, facility-wide AU for all antibacterial agents was significantly lower in non–COVID-19 patients during the COVID-19 period versus the pre–COVID-19 period (with relative decreases of 8%, 7%, and 8% in hospitals A, B, and C, respectively).

AU for broad-spectrum antimicrobials was greater in COVID-19 patients compared to non–COVID-19 patients at the onset of the pandemic. AU for all antibacterial agents in non–COVID-19 patients decreased in the COVID-19 period compared to the pre–COVID-19 period.