TOPLINE

Among adults hospitalized with influenza who presented to US emergency departments (EDs) over 10 years, about 14% did not receive antiviral treatment in the ED despite guidelines recommending immediate therapy for all hospitalized patients. The treatment rate was 91% in 2020 but dropped to 73% in 2021; in 2025, it rose to 85%, the lower end of pre-pandemic levels (85%-91%).

METHODOLOGY

• Researchers used electronic health record data aggregated in Epic Cosmos to conduct a retrospective cohort study of hospitalized adults with influenza who presented to EDs during 2016-2025.
• The study included 483,459 hospitalized adults with influenza: 85.35% were older than 50 years, and approximately 2.55% died.
• Influenza was identified using diagnostic codes or laboratory results that confirmed influenza A or B.
• Researchers assessed the proportion of hospitalized adults with influenza who received antiviral therapy in the ED.
• They also examined the demographic and clinical differences between the treated and untreated patients and trends in treatment over time.

TAKEAWAY

• Antivirals were initiated in the ED for 86.25% of patients, and nearly all of them (98.99%) received oseltamivir.
• The treatment rate remained between 85.14% and 91.08% during 2016-2020, fell sharply to 72.70% in 2021, and then rose gradually to 85.11% in 2025.
• Compared with younger adults (aged 18-30 years), older adults aged 40-50 years and 78-85 years had higher odds of receiving antiviral therapy (odds ratio [OR], 1.23; 95% CI, 1.17-1.29 and OR, 1.54; 95% CI, 1.48-1.61, respectively).
• The odds of receiving antiviral treatment were lower for patients hospitalized in the South (OR, 0.95; 95% CI, 0.93-0.97) and West (OR, 0.78; 95% CI, 0.76-0.80) than for those hospitalized in the Northeast. Treatment rates were moderately correlated with the proportion of hospitalized patients in the ED who had influenza (Pearson correlation coefficient, 0.59).

IN PRACTICE

"The proportion of patients receiving antivirals significantly dropped during the COVID-19 pandemic and has not returned to pre-pandemic levels. Given the increase in ED boarding, urgent interventions are needed to boost antiviral initiation in the ED for hospitalized patients with influenza," the authors wrote.

SOURCE

The study was led by Kevin G. Buell, MBBS, MS, Rush University Medical Center, Chicago. It was published online on September 26, 2026, in The Journal of Emergency Medicine.

LIMITATIONS

Because the study relied on aggregated Epic Cosmos data that lacked comorbidity and illness severity variables, risk-adjusted analyses were not possible. The database covers only the health systems on the Epic platform, which may limit generalizability to other systems. Identifying patients through diagnostic codes may have caused those whose records were incomplete or those who skewed the cohort toward more severe disease to be missed. Owing to its descriptive design, the study could not establish causality.

DISCLOSURES

No specific funding was reported for this study. The authors reported having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.