Doctors warn about false negatives when taking at-home COVID-19 tests

Posted at 8:37 AM, Dec 30, 2021
and last updated 2021-12-30 08:57:02-05

(WXYZ) — At-home COVID-19 testing kits have been hard to find, but if you do get your hands on one, the FDA says at-home tests can detect the Omicron variant but it may not be as sensitive to it. This means, there's more room for false negatives.

So as you get ready to watch the ball drop or pop the champagne, doctors are urging people not to immediately assume your negative at-home covid test means you’re in the clear.

“The problem with the at-home tests is that the false negativity rate is about 20%,” Medical Director of Community Health at Beaumont Grosse Pointe Dr. Asha Shajahan said.

She says roughly 2 out of every 10 negative at-home test results is actually positive. When it comes to the Omicron variant, that number may be even higher.

“Just going by one home test, since the false-negative rate is so high, it could falsy mislead you to believing you’re negative when actually you are positive,” Dr. Shajahan said.

According to the state health department, there are now at least 75 confirmed cases of Omicron in Michigan.

The country’s top infectious disease expert Dr. Anthony Fauci still encourages the use of at-home tests.

“In some of the tests, there appears to be somewhat of a diminution, not a disappearance, but a diminution of the sensitivity,” Dr. Fauci said.

Dr. Shajahan says at-home tests are more accurate when you’re symptomatic and are used over multiple days. That’s because these tests measure for antigens.

“The antigen test is actually testing your immune response to the virus and it’s a one-time immune response that it’s testing whereas the molecular test, which is what the PCR test is, does viral replication, so it tests it multiple times so it's more accurate of a test,” she said.

Doctors advise anyone not trying to risk infecting other this New Year's to get a PCR test. Dr. Fauci also says if your NYE plans involve a big party to maybe rethink that and scale it down.