An epidemiological study of multisystem inflammatory syndrome in children (MIS-C) and young adults among COVID-19-positive patients - data from National Inpatient Sample database.

During the pandemic of COVID-19, a novel atypical set of clinical findings was seen among several children with recent or current exposure to the virus. It was termed the "multisystem inflammatory syndrome in children" (MIS-C). Our study used the 2021 National Inpatient Sample to study the associations of sex, race, and age with the incidence of MIS-C among COVID-19-positive children. Out of 69,440 COVID-19-positive children, 2,790 (4.0%) reported MIS-C. The incidence of MIS-C was highest among those aged 8 years old (17,130 MIS-C cases per 100,000 COVID-19 patients), Asian or Pacific Islanders (API) (5,346 MIS-C per 100,000 COVID-19 cases), and males (4,734 cases per 100,000 COVID-19 cases). Furthermore, 7.9% of MIS-C cases met the classification of Kawasaki disease.