Frequency of Antibiotic Overtreatment and Associated Harms in Patients Presenting With Suspected Sepsis to the Emergency Department: A Retrospective Cohort Study.

Background: Treatment guidelines recommend rapidly treating all patients with suspected sepsis with broad-spectrum antibiotics. This may contribute to antibiotic overuse. We quantified the incidence of antibiotic overtreatment and possible antibiotic-associated harms among patients with suspected sepsis.

Methods: We reviewed the medical records of 600 adults treated for suspected sepsis with anti-methicillin-resistant Staphylococcus aureus and/or antipseudomonal β-lactam antibiotics in the emergency departments of 7 hospitals, 2019-2022, to assess their post hoc likelihood of infection, whether narrower antibiotics would have sufficed in retrospect, and possible antibiotic-associated complications. We used generalized estimating equations to assess associations between likelihood of infection and hospital mortality.

Results: Of 600 patients, 411 (68.5%) had definite (48.0%) or probable (20.5%) bacterial infection and 189 (31.5%) had possible but less likely (18.3%) or definitely no (13.2%) bacterial infection. Among patients with definite/probable bacterial infection, 325 of 411 (79.1%) received antibiotics that were overly broad in retrospect. Potential antibiotic-associated complications developed in 104 of 600 (17.3%) patients within 90 days, most commonly new infection or colonization with organisms resistant to first-line agents (48/600 [8.0%]). Mortality was higher for patients with less likely/definitely no bacterial infection versus definite/probable bacterial infections (9.0% vs 4.9%; adjusted odds ratio [aOR], 2.25 [95% confidence interval{CI}, 1.70-2.98]), but antibiotic-associated complication rates were similar (14.8% vs 18.5%; aOR, 0.79 [95% CI, .60-1.05]).

Conclusions: Among 600 patients treated with broad-spectrum antibiotics for possible sepsis, 1 in 3 most likely did not have a bacterial infection, 4 in 5 of those with bacterial infections were treated with regimens that were broader than necessary in retrospect, and 1 in 6 developed antibiotic-associated complications.