Discussion

During the SARS-CoV-2 omicron variant pandemic wave (December 2021–Feburary 2022), our point-prevalence study demonstrates that the use of antibiotics in COVID-19 pneumonia remained high. Our numbers are similar to those described in the early pandemic literature. ^{Reference Karaba, Jones and Helsel1–Reference Lansbury, Lim, Baskaran and Lim3} This finding is concerning because the rate of bacterial coinfection has been well characterized to be <10%. ^{Reference Karaba, Jones and Helsel1–Reference Lansbury, Lim, Baskaran and Lim3} What is even more concerning is that SARS-CoV-2 test results had no impact on antibiotic prescribing. We hypothesized that those with COVID-19 pneumonia would have received fewer antibiotics than those who tested negative; however, that hypothesis was not confirmed in this study. In fact, our data uniquely confirm that most antibiotics were prescribed or continued after the positive SARS-CoV-2 result. Although uncertainty during initial workup may warrant empiric antibiotics, especially in patients being admitted to the ICU, most patients in our cohort were admitted to general care.

Unsurprisingly, most patients did not receive respiratory cultures because national guidelines no longer recommend them because culture results rarely influence antibiotic therapy selection. ^{Reference Metlay, Waterer and Long5} However, these guidelines were published before the COVID-19 pandemic, and the risk of antibiotic overutilization in the face of diagnostic uncertainty in this population may necessitate reconsidering this recommendation. The rates of collection of inflammatory markers in COVID-19 patients, such as PCT, were similar in our cohort to the rates reported in the literature (60%). ^{Reference Fabre, Karaba and Amoah8} Procalcitonin ordering was associated with increased antibiotic use. We speculate that this may be due to selective use of PCT in cases of higher clinical suspicion of bacterial coinfection and/or the results of this diagnostic test in COVID-19 patients is being interpreted similarly to prepandemic evidence describing a level >0.25–0.5 ng/mL as consistent with bacterial pneumonia. ^{Reference Self, Balk and Grijalva6} The lack of evidence correlating elevated PCT and bacterial coinfection in COVID-19 pneumonia and the literature describing high values due to the inflammatory state from SARS-CoV-2 infection itself should be a focus of diagnostic stewardship moving forward. ^{Reference Fabre, Karaba and Amoah8,Reference Lippi and Plebani9}

Our study had several limitations. First, our survey was conducted in a short period, which likely limited participation by Vizient member hospitals. Although our study only included 11 hospitals, our results demonstrate similar practice patterns across geographic region and include statistically significant findings 252 patients. Second, sites that volunteered were primarily academic medical centers and university hospitals. Therefore, our results may not be generalizable to practices in community hospitals. Third, data were extracted at a single time point, so antibiotic duration and final culture results were not captured.

In conclusion, among acutely hospitalized patients evaluated for COVID-19 pneumonia during the SARS-CoV-2 omicron variant wave, antibiotic use in COVID-19 patients remained high. Noninvasive diagnostic testing with PCT, which has mixed results in the literature for use in guiding antibiotic prescribing in COVID-19 patients, was more common than collection of respiratory cultures and did not reduce antibiotic utilization. Antimicrobial and diagnostic stewardship should remain a top priority for patients admitted with COVID-19 to mitigate unnecessary antibiotic use.