(190) Trends in Antiviral Use for Influenza Among Children in the US Between 2010-2019

Publication Number: 1235

Background: Young children and those with co-morbidities are at high risk for complications from influenza infections, such as pneumonia, meningitis, and hospitalization. Treatment with influenza antivirals reduces duration of illness and influenza complications. Yet, the rate of prescribing among children, and especially high-risk children, is unknown.

Objectives: To describe the trends in antiviral use in the pediatric population across nine influenza seasons (2010-2019) in the US.

Methods: Using IBM MarketScan commercial claims data from July 2010 through June 2019, we identified influenza antiviral drug (Oseltamivir, Zanamivir, Peramivir, and Baloxavir) dispensings in children ( < 18 years). Among children dispensed an antiviral we measured age, presence of an influenza diagnosis (within past 2days), and comorbidities (presence of AHRQ Chronic Condition Indicator, CCI, within preceding 365 days). For each influenza season, we calculated the rate of antiviral dispensing among all children enrolled in the database and compared the dispensing rates among seasons calculating rate ratios and using the 2010-2011 season as reference. Finally, we contrasted rates of antiviral dispensing with rates of influenza reported by surveillance systems.

Results: We identified 1,359,527 influenza antiviral dispensings over the period from July 2010 through June 2019. The mean age was 8.8 years (SD=4.6) with 29.1% ≤5 years. From these dispensings, 29.8% had an influenza diagnosis corresponding with the dispensing. Oseltamivir was the most common antiviral (99.8% of dispensings). Among those dispensed an antiviral, 27.9% had at least one comorbidity diagnosis (CCI). The most common disease categories from the CCI were respiratory disease (16.1%), mental disorders (7.2%) and nervous system disorders (5.5%). The seasonal rate of antiviral dispensing ranged from 548 per 100,000 children in the 2011-2012 season to 4957 per 100,000 children in the 2017-2018 season. In comparison to the 2010-2011 season, the rate ratio of influenza antiviral dispensing was 0.33 (95% CI 0.33-0.33) in '11-'12, 1.84 (1.83-1.85) in '12-'13, 0.81 (0.81-0.82) in '13-'14, 2.31 (2.30-2.33) in '14-'15, 0.86 (0.85-0.87) in '15-'16, 1.82 (1.81-1.83) in '16-'17, 3.13 (3.11-3.15) in '17-'18 and 2.72 (2.70-2.73) in '18-'19 . This variation coincides with the influenza diagnosis reported by the Centers for Disease Control and Prevention.

Conclusions: We observed marked variation in antiviral dispensings for US children over our study period with higher rates of dispensing in more recent years. Further studies are required to understand the factors affecting prescribing of antivirals for influenza.