Lower plasma calcium associated with COVID-19, but not with disease severity: a two-centre retrospective cohort study.

Background: Previous studies indicate hypocalcaemia as a potential diagnostic and prognostic marker of corona-virus disease 2019 (COVID-19). Our aim was to investigate these relations in more detail in a large test cohort and an independent validation cohort.

Methods: We retrospectively included 2792 COVID-19 suspected patients that presented to the emergency department (ED) of two hospitals.