Influenza antivirals underused in high-risk outpatients
New research findings from five recent influenza seasons showed that influenza antivirals were underused in outpatients at a high risk for influenza-related complications who could have benefited from early treatment.
Writing in Clinical Infectious Diseases, researchers said just 15% of high-risk outpatients with acute respiratory illness (ARI) who presented early to care during the study period were prescribed an antiviral medication, including 37% of those with laboratory-confirmed influenza.
The CDC recommends annual influenza vaccination for everyone aged 6 months and older and early antiviral treatment in cases of suspected or confirmed influenza in patients at higher risk for complications.
The researchers analyzed antiviral prescriptions and clinical data for high-risk outpatients aged at least 6 months with an ARI who were enrolled in the U.S. Influenza Vaccine Effectiveness Network during five influenzas seasons from 2011-2012 to 2015-2016. Using the CDC guidelines for antiviral treatment, they considered a patient at high risk for influenza-associated complications if they were aged younger than 2 years, aged 65 years or older, were pregnant or had evidence of a specific chronic underlying health condition.
Among 4,861 high-risk patients who presented within 2 days of symptom onset, 15% were prescribed an antiviral medication, according to the study. Of the 1,292 high-risk patients with influenza infections confirmed via rRT-PCR who showed up early, 37% received an antiviral prescription.
The researchers found that just 40% of high-risk outpatients with laboratory-confirmed influenza presented to care within 2 days — older adults were the least likely to show up early and the most likely to present after 4 days. Modeling showed that patients who presented early or had a positive influenza test result were more than four times likelier to receive a prescription for antivirals. Presence of a fever — which was not reported in 25% of patients — made the patient three times more likely to receive a prescription.
“Many viruses can cause an ARI, which may partially explain why providers are hesitant to treat for influenza among patients with ARI-associated symptoms,” the researchers wrote. “Also, sensitive diagnostic assays, such as those based on nucleic acid detection, are expensive and infrequently used in outpatient settings.”
They said efforts are needed to increase appropriate prescribing of antivirals to reduce influenza-associated complications. – by Gerard Gallagher
Disclosures: Please see the study for all authors’ relevant financial disclosures.