FDA Warns of COVID-19 Antigen Test False Positives as Report Flags Quidel on Accuracy

The U.S. Food and Drug Administration (FDA) has issued an advisory to clinical labs and healthcare providers about the potential for COVID-19 antigen tests from Abbott, BD, and Quidel to produce false positives after receiving reports from nursing communities and other settings, reports MedTech Dive . The alert urges users to follow the instructions, warning that false results can come from improper storage and reading them at the wrong time. The agency added that false positives could be an unavoidable outcome of using tests with specificities below 100 percent; if a test with 98 percent specificity is used to screen a population in which 10 percent of people are infected, two out of every 10 positive results will be false. The alert follows a New York Times report on a University of Arizona study citing concerns about the ability of a Quidel rapid antigen test to detect asymptomatic cases, which produced more false positives than positives verified by PCR tests.