Earlier this month, the White House announced that it would invest $1 billion to make more at-home COVID-19 tests available to Americans. That’s in addition to the $2 billion the Biden administration said in September it would allocate for at-home tests.
With millions of more at-home tests expected to be available in the coming months, a viewer texted the VERIFY team, asking about the accuracy of rapid at-home tests.
Are at-home COVID-19 rapid tests as accurate as rapid tests done at testing sites?
Yes, at-home COVID-19 rapid tests are as accurate as rapid tests done at testing sites.
WHAT WE FOUND
There are two types of COVID-19 tests that can be performed at home and have been authorized by the U.S. Food and Drug Administration (FDA).
One is a molecular test, more commonly known as a PCR (polymerase chain reaction) test. These tests detect the genetic material of the SARS-CoV-2 virus, according to the Mayo Clinic.
PCR tests, which are also available at testing sites, are highly accurate and considered the “gold standard,” said Dr. Saralyn Mark, the COVID-19 lead for the American Medical Women’s Association. However, an at-home PCR test requires a person to take a sample, mail it to a lab to be tested and wait several days for the results.
The other type of at-home test, which is the focus of the viewer question, is an antigen rapid test. The Mayo Clinic says antigen tests detect certain proteins in the SARS-CoV-2 virus.
The results of these tests can be provided in minutes as opposed to days. However, antigen rapid tests, both at home and provided in clinical settings, are less accurate than PCR tests, according to the Cleveland Clinic.
Mark says as the pandemic has continued, the accuracy of rapid antigen tests has improved to the point where accuracy levels are generally in the 80% to 90% range.
“Over time, these rapid tests have become a lot more accurate,” she said. “They’re certainly easy to do and the results can be returned relatively quickly.”
The FDA has a list of authorized at-home tests on its website.
One of the authorized at-home tests, the QuickVue At-Home OTC COVID-19 Test, gave a correct positive result 83% of the time compared to a PCR test and a correct negative result 99% of the time, according to a clinical study submitted to the FDA. The CareStart COVID-19 Antigen Home Test correctly provided a positive result at least 87% of the time and a correct negative result at least 98% of the time in a clinical study. The Flowflex COVID-19 Antigen Home Test, which the FDA authorized for emergency use on Oct. 4, gave a correct positive result 93% of the time and a correct negative result 100% of the time in a clinical study.
The FDA says most at-home antigen tests are authorized for serial testing – meaning a person gets tested more than once over the span of a few days. The Centers for Disease Control and Prevention (CDC) says this testing strategy helps ensure test results are accurate.
“By testing more frequently, you might detect COVID-19 more quickly and could reduce the spread of infection,” the CDC says.
Mark said antigen tests tend to be more accurate when done three to five days after being exposed to COVID-19. The test is also typically more accurate when a person is symptomatic because they likely have a higher viral load.
“The test may be extremely accurate if it's done perfectly in the right window of time,” she said.
Mark advised people to follow the instructions provided with at-home tests to ensure the most accurate result possible.
“The important point here is the test will only be as good as you obtain the samples,” she said. “So, if you are not sampling correctly, and you don’t have the sample process correctly, you may receive an inaccurate result.”
Nebraska Medicine says the rapid tests are useful, but they aren’t perfect. People can check with their doctor to determine if the results of their rapid at-home test need to be confirmed with a more accurate PCR test.