While fatality was fortunately rare, complications including hospitalization, hypoxemia and pneumonia were more frequent in children and adolescents either diagnosed or hospitalized with COVID-19 than with seasonal influenza. Furthermore, labored breathing, loss of smell and gastrointestinal issues were more prevalent symptoms for younger people inflicted with COVID-19 than with influenza.

These findings, along with that of significant treatment heterogeneity for children/adolescents hospitalized with COVID-19, were presented in the study “30-day outcomes of Children and Adolescents with COVID-19: An International Experience,” published May 28 by Pediatrics.

Early in the pandemic, opinions around the COVID-19 impact on children and adolescents ranged from it being no more than the common flu to fear of its potential impact on lesser-developed immune systems. This OHDSI global network study compared the real-world observational data of more than 242,000 children/adolescents diagnosed and nearly 10,000 hospitalized with COVID-19 to more than 2,000,000 diagnosed with influenza across five countries (France, Germany, South Korea, Spain, United States) to provide a clearer picture of its impact.

Asthma and obesity were the most common baseline comorbidities — a common finding in disease prevalence among a general pediatric population — in the studied databases, but there was a higher prevalence of rare conditions, including congenital malformation/s, neurodevelopmental disorders, and heart disease, among those hospitalized with COVID-19. Pediatric patients with COVID-19 also showed higher rates of labored breathing, loss of smell and gastrointestinal symptoms than those presenting with influenza, which could help improve early diagnosis of COVID-19 among this population.

Adjunctive therapies were the most common treatment options in children/adolescents, though there was global heterogeneity on which particular therapies were used (systemic corticosteroids and famotidine were most common). The most common 30-day complications for hospitalized children/adolescents with COVID-19 were hypoxemia and pneumonia, both of which occurred at a higher rate than hospitalized influenza patients.

There was limited knowledge of the COVID-19 impact on children/adolescents around the world during the first half of 2020, when the OHDSI community collaborated on the CHARYBDIS Project. Findings at the time ranged from a 5.7 % hospitalization rate to another that reported a 63% hospitalization rate. There was a need for reliable evidence on the demographics, comorbidities, symptoms, in-hospital treatments, and health outcomes among children/adolescents to inform clinical decision-making.

“This study addressed critical questions that were weighing down on both the healthcare community and the general population — how was COVID-19 impacting our youngest population,” said study lead Talita Duarte-Salles, PhD, an epidemiologist at IDIAP Jordi Gol. “While some claimed that COVID-19 was no different than the flu early last year, the real-world evidence we generated through open science showed something quite different. It was relieving to see that fatality was rare, but clearly both complications and symptoms showed the COVID-19 was no flu in children and adolescents.”

The study was developed and executed by the OHDSI (Observational Health Data Sciences and Informatics) community, a multi-stakeholder, interdisciplinary network that collaborates globally to bring out the value of health data through open science and large-scale analytics. This study resulted from the CHARYBDIS Project, which set out to:

1) Describe the baseline demographics, clinical characteristics, treatments, symptoms and outcomes of interest among individuals with COVID-19 overall and stratified by sex, age and specific comorbidities

2) Describe characteristics and outcomes of influenza patients between September 2017 and April 2018 compared to the COVID-19 population

This project has resulted in several published studies, including ones on general COVID-19 phenotyping, patients with autoimmune disease, and use of repurposed and adjunctive drug therapies. Several others are undergoing peer review and have been posted to a preprint server; OHDSI’s work on COVID-19 can be found here.

“Generating reliable evidence that can inform clinical decision-making for children and adolescents was so important, and it doesn’t happen without collaboration and the foundation of open-source tools and practices developed for years in this network,” Duarte-Salles said. “It was truly inspiring the way our OHDSI community rallied together globally in the face of this unprecedented pandemic and collaborated together.”