Factors Associated With Severe Illness in Patients Aged <21 Years Hospitalized for COVID-19

Hosp Pediatr. 2022 Sep 1;12(9):760-783. doi: 10.1542/hpeds.2022-006613.


Objectives: To describe coronavirus disease 2019 (COVID-19)-related pediatric hospitalizations during a period of B.1.617.2 (Δ) variant predominance and to determine age-specific factors associated with severe illness.

Methods: We abstracted data from medical charts to conduct a cross-sectional study of patients aged <21 years hospitalized at 6 United States children's hospitals from July to August 2021 for COVID-19 or with an incidental positive severe acute respiratory syndrome coronavirus 2 test. Among patients with COVID-19, we assessed factors associated with severe illness by calculating age-stratified prevalence ratios (PR). We defined severe illness as receiving high-flow nasal cannula, positive airway pressure, or invasive mechanical ventilation.

Results: Of 947 hospitalized patients, 759 (80.1%) had COVID-19, of whom 287 (37.8%) had severe illness. Factors associated with severe illness included coinfection with respiratory syncytial virus (RSV) (PR 3.64) and bacteria (PR 1.88) in infants; RSV coinfection in patients aged 1 to 4 years (PR 1.96); and obesity in patients aged 5 to 11 (PR 2.20) and 12 to 17 years (PR 2.48). Having ≥2 underlying medical conditions was associated with severe illness in patients aged <1 (PR 1.82), 5 to 11 (PR 3.72), and 12 to 17 years (PR 3.19).

Conclusions: Among patients hospitalized for COVID-19, factors associated with severe illness included RSV coinfection in those aged <5 years, obesity in those aged 5 to 17 years, and other underlying conditions for all age groups <18 years. These findings can inform pediatric practice, risk communication, and prevention strategies, including vaccination against COVID-19.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • COVID-19* / epidemiology
  • COVID-19* / therapy
  • Child
  • Coinfection*
  • Cross-Sectional Studies
  • Hospitalization
  • Humans
  • Infant
  • Obesity
  • Respiratory Syncytial Virus Infections* / epidemiology
  • SARS-CoV-2
  • United States / epidemiology

Supplementary concepts

  • SARS-CoV-2 variants