The Los Angeles Post

FDA: Repeat at-home tests to avoid false negatives

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The Food and Drug Administration (FDA) issued guidance on Thursday recommending that people testing themselves for COVID-19 at home take a repeat test within 48 hours to rule out a potential false negative.

  • In its guidance, the FDA noted that at-home tests are less likely to detect the coronavirus than PCR lab tests. This inaccuracy is more likely to occur early in the infection in people who display no symptoms.
  • “Currently, all at-home COVID-19 antigen tests are FDA-authorized for repeat, or serial use. This means people should use multiple tests over a certain time period, such as 2-3 days, especially when the people using the tests don’t have COVID-19 symptoms,” the FDA said.

People should keep multiple tests on hand for the purpose of this new guidance, the agency said. Most over-the-counter, at-home COVID-19 tests are sold in multipacks.

 

The guidance:

  • The FDA recommended that people take one initial test if they suspect they may be infected or exposed to COVID-19. If they test negative and have some symptoms, then they should test again 48 hours after the first test. If the second test is still negative, a laboratory molecular-based test should be considered.
  • If a person has no COVID-19 symptoms but believes they have been exposed to the virus, the FDA said they should also test themselves a second time, also 48 hours after their first at-home test. If the second test is negative, they should take an additional third test another 48 hours afterward.

If any of these at-home tests come back positive, then the individual likely has COVID-19 and should follow guidance from the Centers for Disease Control and Prevention.