Background: Recent population-based data are limited regarding influenza-associated hospitalizations in U.S. children.

Methods: We identified children <18 years hospitalized with laboratory-confirmed influenza during 2010-2019 seasons through CDC´s Influenza Hospitalization Surveillance Network. Adjusted hospitalization and in-hospital mortality rates were calculated, and multivariable logistic regression was conducted to evaluate risk factors for pneumonia, intensive care unit (ICU) admission, mechanical ventilation, and death.

Results: Over 9 seasons, adjusted influenza-associated hospitalization incidence rates ranged from 10-375 per 100,000 persons each season and were highest among infants <6 months. Rates decreased with increasing age. The highest in-hospital mortality rates were observed in children <6 months (0.73 per 100,000 persons). Over time, antiviral treatment significantly increased from 56% to 85% (P < .001) and influenza vaccination rates increased from 33% to 44% (P = .003). Among the 13,235 hospitalized children, 2,676 (20%) of hospitalized children were admitted to the ICU, 2,262 (17%) had pneumonia, 690 (5%) required mechanical ventilation, and 72 (0.5%) died during hospitalization. As compared with those <6 months of age, hospitalized children ≥13 years had higher odds of pneumonia (adjusted odds ratios [aOR], 2.7; 95% confidence interval [CI], 2.1-3.4), ICU admission (aOR, 1.6; 95% CI, 1.3-1.9), mechanical ventilation (aOR, 1.6; 95% CI, 1.1-2.2), and death (aOR, 3.3; 95% CI, 1.2-9.3).

Conclusions: Hospitalization and death rates were greatest in younger children at the population level. Among hospitalized children, however, older children had a higher risk of severe outcomes. Continued efforts to prevent and attenuate influenza in children are needed.