Effectiveness of Oseltamivir in Hospitalized Children With Laboratory-Confirmed Influenza, 2014-2023
Kacie Rytlewski1, Angela Dunn2, Alissa O'Halloran3
1Department of Pediatrics, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora.
Insights
Oseltamivir treatment significantly reduced intensive care unit (ICU) admissions and hospital length of stay (LOS) in children hospitalized with influenza. These findings support national guidelines recommending prompt antiviral therapy for pediatric flu patients.
Area of Science:
- Pediatric Infectious Diseases
- Antiviral Therapeutics
- Public Health Surveillance
Background:
- National guidelines recommend prompt antiviral treatment for hospitalized children with influenza.
- Recent trends show a decline in oseltamivir use for pediatric influenza hospitalizations.
- Previous studies on oseltamivir effectiveness in children have limitations including bias and incomplete data.
Purpose of the Study:
- To evaluate the association between oseltamivir receipt and the risk of intensive care unit (ICU) admission.
- To assess the impact of oseltamivir on hospital length of stay (LOS) in pediatric influenza cases.
- To provide evidence supporting or refuting current treatment recommendations.
Main Methods:
- A cohort study utilizing data from the Influenza Hospitalization Surveillance Network (FluSurv-NET) across 13 US states.
- Inclusion of laboratory-confirmed influenza hospitalizations in children under 18 years with documented symptom onset dates (2014-2023, excluding 2020-2021).
- Analysis employed adjusted Cox proportional hazard models with oseltamivir receipt as a time-dependent exposure to determine primary (ICU admission) and secondary (LOS) outcomes.
Main Results:
- The study included 6044 children for ICU analysis and 7103 for LOS analysis; 70.2% and 80.9% received oseltamivir, respectively.
- Oseltamivir treatment was associated with a 31% reduction in the hazard of ICU admission (aHR, 0.69; 95% CI, 0.60-0.80).
- Oseltamivir treatment also significantly shortened hospital LOS (aHR, 1.13; 95% CI, 1.06-1.21).
Conclusions:
- Oseltamivir treatment in hospitalized children with influenza is associated with significantly lower rates of ICU admission.
- The findings confirm that oseltamivir effectively reduces hospital length of stay for pediatric influenza patients.
- Results strongly support current national recommendations for early administration of oseltamivir in children with suspected or confirmed influenza.
Importance:
National organizations recommend antiviral treatment for hospitalized children with influenza; however, use in this setting has recently declined. Studies of oseltamivir effectiveness in children are limited by misclassification bias, unknown symptom onset date, and incomplete capture of antiviral use prior to admission.
Objective:
To assess the association between oseltamivir receipt and intensive care unit (ICU) admission and hospital length of stay (LOS) among pediatric influenza-associated hospitalizations.
Design, Setting, And Participants:
This cohort study used data that were obtained from the Influenza Hospitalization Surveillance Network (FluSurv-NET), which conducts US population-based surveillance for laboratory-confirmed influenza hospitalizations for all ages across 13 states. The study data include seasons 2014 to 2015 through 2022 to 2023, excluding 2020 to 2021. Participants included children aged younger than 18 years who were hospitalized with laboratory-confirmed influenza and for whom a respiratory symptom onset date was available. These data were analyzed from October 2024 through May 2026.
Exposures:
Oseltamivir receipt as a time-dependent exposure.
Main Outcome(S) And Measure(S):
The primary outcome was time from symptom onset to ICU admission. Secondary outcome was time from admission to discharge (LOS). Adjusted Cox proportional hazard models (aHR) with oseltamivir receipt as a time-dependent exposure were used.
Results:
After exclusions, 6044 influenza cases were included in the primary ICU analysis, of whom 4240 (70.2%) received oseltamivir, and 7103 cases were included in the secondary LOS analysis, of whom 5746 (80.9%) received oseltamivir. In the ICU analysis, the median (IQR) age was 3 (1-7) years, 3382 (56%) were male and 3721 (44%) were female, and 2937 (49%) had 1 or more medical comorbidity-the most common of which was asthma in 1547 children (26%). In adjusted models, compared with untreated children, oseltamivir treatment reduced the hazard of ICU admission (aHR, 0.69; 95% CI, 0.60-0.80) and shortened LOS (analyzed as hazard of hospital discharge; aHR, 1.13; 95% CI, 1.06-1.21).
Conclusions And Relevance:
In this cohort of children hospitalized with influenza, oseltamivir treatment was significantly associated with a reduced risk of ICU admission by 31% and decreased hospital LOS. These findings demonstrate the benefits of oseltamivir receipt and support current national recommendations for oseltamivir treatment as soon as possible in children hospitalized with suspected or laboratory-confirmed influenza.
Related Concept Videos
01:27Influenza
01:25Inhibitors Of Virion Release