Introduction: Influenza is a common and potentially serious disease in children. This retrospective cohort study examined the incidence of complications and associated risk factors in this population, and the effects of antiviral treatment.
Methods: Data for children aged ≤17 years with a clinical diagnosis of influenza (ICD-9-CM codes 487.xx or 488.xx) during the 2006-2010 influenza seasons (including the 2009-2010 pandemic season) were obtained from US insurance claims databases. Unconditional logistic regression was used to evaluate the effect of antiviral treatment on the incidence of complications and healthcare resource utilization during the 30 days post the index influenza diagnosis. A sub-analysis in children aged <1 year was performed.
Results: Antiviral treatment was used in 315,128 (39.53%) of 797,284 cases. The risk of complications was higher in children with pre-existing conditions, e.g., asthma (odds ratio [OR] = 1.86) or cystic fibrosis (OR = 1.67) than otherwise healthy children. Antiviral treatment reduced the 30-day risk of complications, hospitalization, emergency department visits, and ≥2 outpatient visits versus no treatment (ORs = 0.76, 0.69, 0.76, and 0.81, respectively); 30-day risks were further reduced by early treatment (within 2 days of diagnosis). The sub-analysis included 19,666 children aged <1 year; 7.38% received antiviral treatment during the pre-pandemic seasons and 33.00% during the pandemic season. Findings were similar to the main analyses; however, healthcare resource utilization was only significantly reduced by early treatment.
Conclusions: Antiviral treatment is associated with reduced risk of complications and healthcare resource utilization in children of all ages with influenza, especially when initiated early.