*Disclaimer: Much of this content is now outdated. It was developed early in the pandemic to communicate the basics of COVID-19 testing when the main question we were being asked was “should I get an antibody test or a molecular test?” Back then, we had access to antibody or PCR tests. The distinction of antigen versus PCR or NAAT did not become relevant until months later when additional assays for SARS-CoV-2 became available.
blog posts about COVID-19
Interpreting results
Step by step explanation of how to calculate positive and negative predictive values, which provide the likelihood that a positive result is a true positive, or a negative is a true negative
Mary McQuilkin, NP, MPH 