News and Updates

Researchers Adjust Antibody Tests to Improve Study Data Quality

July 28, 2020 

An important part of the research process is making the best decisions possible at each stage and continually making changes as more and better information becomes available. Learning about the novel coronavirus is real-time discovery.

Because COVID-19 antibody tests are relatively new, they must undergo a review process to confirm that they work and that their results are statistically “valid.” Tests are measured by sensitivity and specificity. Sensitivity is a measure of how well a test finds antibodies in someone who has been infected. Specificity is a measure of how accurate the test is at confirming negative results. 

The antibody tests we have been using as part of the COVID-19 Community Research Partnership have undergone 3 separate reviews: 1 by Wake Forest Baptist Health, 1 by LabCorp, and 1 by the National Cancer Institute (NCI), at the request of the Food and Drug Administration (FDA). 

In the first 2 reviews, the test sensitivity was 90% and test specificity was 100%.  This meant that the test identified antibodies in 9 out of 10 samples from patients known to have COVID-19 and did not identify any antibodies in samples that had been collected and saved from before COVID-19 existed (no false positives).  

In the third review, test sensitivity showed 93% for one type of antibodies (IgM) and 77% for the other type (IgG), meaning there were a larger number of false negative tests. Test specificity was 97.5% for IgM and 100% for IgG. 

Although the test we have been using performed well on the first 2 reviews and the average of the 3 reviews showed overall good performance, the third review raised concerns that the test may not be sensitive enough (too many false negatives).  As a result and because we continually want to improve the quality of our data, we have changed our antibody tests.