"For COVID" or "With COVID": Classification of SARS-CoV-2 Hospitalizations in Children.

OBJECTIVES:Pediatric hospitalization rates are used as a marker of coronavirus disease 2019 (COVID-19) disease severity in children but may be inflated by the detection of mild or asymptomatic infection via universal screening. We aimed to classify COVID-19 hospitalizations using an existing and novel approach and to assess the interrater reliability of both approaches.METHODS:This retrospective cohort study characterized severity of illness and likelihood of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection as the cause of hospitalization in pediatric patients <18 years of age. Subjects had positive SARS-CoV-2 nasopharyngeal testing or were diagnosed with multisystem inflammatory syndrome in children and were hospitalized between May 10, 2020 (when universal screening of all admissions began) and February 10, 2021, at a university-based, quaternary care children's hospital in Northern California. Hospitalizations were categorized as either likely or unlikely to be caused by SARS-CoV-2 (novel approach), and disease severity was categorized according to previously published classification of disease severity.RESULTS:Of 117 hospitalizations, 46 (39.3%) were asymptomatic, 33 (28.2%) had mild to moderate disease, 9 (7.7%) had severe illness, and 15 (12.8%) had critical illness (weighted κ: 0.82). A total of 14 (12%) patients had multisystem inflammatory syndrome in children. A total of 53 (45%) admissions were categorized as unlikely to be caused by SARS-CoV-2 (κ: 0.78).CONCLUSIONS:Although COVID-19 has considerable associated morbidity and mortality in children, reported hospitalization rates likely lead to overestimation of the true disease burden.