Number of positive and negative samples is defined as per the diagnostic criteria. Kappa (κ) / [Agreement Criteria]: ≤ 20 / [Poor]; 21–40 / [Fair]; 41–60 / [Moderate]; 61–80 / [Substantial] and 81–100
To investigate the concordance of results across four immunoassays targeting different antigens for sera collected at the beginning of the SARS-CoV-2 pandemic in the United States.
