Factors Associated With Nonprescription of Oseltamivir for Infant Influenza Over 9 Seasons.

Abstract

Background: The Centers for Disease Control and Prevention (CDC) recommends oseltamivir phosphate for children <2 years old with confirmed or suspected influenza as they are at high risk for complications. We analyzed infant characteristics associated with nonprescription of oseltamivir over 9 years.

Methods: We conducted a retrospective electronic health record (EHR) review of infants <12 months old born between January 1, 2012 and December 31, 2019 within the University of Pittsburgh Medical Center health system in Southwestern Pennsylvania who had >2 well-child visits during their first year. Infants with a confirmed positive test for influenza were included in the analysis. Factors associated with infant oseltamivir nonprescription were assessed using multivariable logistic regression.

Results: Of 457 infants with confirmed influenza, 86% were prescribed oseltamivir. The proportion of infants prescribed oseltamivir increased from an average of 64.6% during the 2012-2016 influenza seasons to 90.4% during the 2016-2020 influenza seasons. Infants were more likely to not be prescribed oseltamivir if they experienced >2 days of influenza symptoms (odds ratio (OR): 9.4, 95% CI: 4.8, 18.7, P < .001), were diagnosed during the 2012-2016 influenza seasons (OR: 4.2, 95% CI: 1.8, 9.5, P < .001), tested positive for influenza via a multiplex/reverse transcriptase polymerase chain reaction test (OR: 6.7, 95% CI: 2.7, 16.3, P < .001; OR: 2.7, 95% CI: 1.1, 7.1; P = .04), or did not have a fever at point-of-care (OR: 2.3, 95% CI: 1.2, 4.6, P = .01).

Conclusion: Adherence to CDC influenza antiviral treatment guidelines for infants is high and improved over time. However, the provision of targeted education to providers may further improve oseltamivir prescribing practices for high-risk children <12 months of age.