Clinical outcomes and healthcare utilization of hospitalized children with influenza versus COVID-19.

Abstract

Background: Influenza and coronavirus disease 2019 (COVID-19) are major causes of pediatric respiratory illness with overlapping clinical features but potentially differing impacts on healthcare utilization and outcomes.

Purpose: To compare the clinical presentations, healthcare resource utilization, and outcomes of children hospitalized with influenza and COVID-19 and address the gaps in pediatric data from Southeast Asia.

Methods: This retrospective observational study included children aged ≤12 years hospitalized with laboratoryconfirmed influenza or COVID-19 at a tertiary hospital in Malaysia between May 1, 2022, and May 1, 2023. Patients with viral or bacterial coinfections were excluded. Influenza A and B cases were collectively analyzed. The patients' demographic data, clinical presentation, resource utilization, and outcomes were also evaluated. Propensity score matching (PSM) was performed to balance the cohorts for age, sex, ethnicity, and comorbidities. Outcomes were compared using standardized mean differences (SMDs).

Results: A total of 299 patients were included (influenza, n=177; COVID-19, n=122). Patients with influenza were older (median, 3.6 years vs. 1.8 years; P<0.001) and more likely to have fever, cough, and rhinorrhea. COVID-19 patients presented earlier in the illness (median, 2 days vs. 4 days; P<0.001). After PSM, 102 patients were included in each group. Patients with influenza required greater healthcare resource use, including intravenous fluids (60.8% vs. 43.1%; SMD=0.36), empirical antibiotics (40.2% vs. 12.7%; SMD=0.66), respiratory support (40.2% vs. 26.5%, SMD= 0.29), pediatric intensive care unit admission (10.8% vs. 2.9%; SMD=0.32), and longer duration of oxygen therapy (SMD=0.93).

Conclusion: Children hospitalized for influenza demonstrated higher clinical severity and greater healthcare resource utilization than those hospitalized for COVID-19. These findings highlight the burden of influenza and inform hospital resource planning during periods of viral circulation.