Factors Associated with Antiviral Drug Use Among Commercially Insured Children at High Risk for Complications of Influenza

OBJECTIVES: To evaluate the prevalence of antiviral drug use in children in the US with influenza at high risk for complications and to identify factors associated with dispensing. STUDY DESIGN: We conducted a retrospective cohort study of outpatient visits for individuals < 18 years during the 2016-2020 influenza seasons using the Merative MarketScan Commercial Claims and Encounter database. High-risk status was defined using Infectious Disease Society of America definitions and included: age, specific comorbidities, pregnancy or postpartum status, and living in a long-term care facility. The primary outcome was antiviral (oseltamivir, zanamivir, baloxavir) dispensing within 2 days of influenza diagnosis. We determined clinical factors associated with antiviral dispensing using modified Poisson regression. RESULTS: A total of 372 372 influenza episodes were identified among 331 389 children at high risk for influenza complications and included in this study. The median (IQR) age was 4.0 years (2.0, 9.0). Overall, during 201 638 (54.1%) episodes of the influenza, antiviral treatment was dispensed. Factors associated with increased antiviral use included asthma, West and South US geographic regions, urgent care settings, and specific health insurance plans. Factors associated with decreased antiviral use include younger age, emergency department setting, Midwest and Northeast geographic regions, and health insurance plans. CONCLUSION: Despite national guidelines recommending that all children at high risk for influenza complications receive antiviral treatment, nearly half of these children at high-risk did not receive an antiviral in our study. We identify several factors associated with decreased antiviral treatment that may serve to inform future interventions aiming to improve the care of vulnerable children with influenza.