IN-DEPTH: Reliability & accuracy of at-home COVID-19 tests

Posted at 11:01 PM, Sep 30, 2021
and last updated 2021-10-01 09:07:57-04

Over a year and a half into the pandemic we're still navigating through day-to-day life with COVID-19.

Some things getting a little more manageable, like access to testing. The days of waiting in line for hours to get a COVID-19 test are behind us.

At home COVID-19 testing has quickly gained popularity, lightening the load for labs already processing thousands of Coronavirus tests, but just how accurate are those tests?

Mckenzie Solo, a social worker who works in the foster care system, said at home rapid tests have completely changed the workflow for the better.

"I have contact with children who have high medical needs or newborn children," Solo said. "There have been weeks where I test you know, five or six times and there's been weeks where I don't test at all because I've been, you know, four out of the five days of the week I was in the office or doing paperwork at home."

Solo said before rapid at-home COVID tests, the caseload for some workers increased especially when they were exposed or had to wait for lab results to come in. Since she has such close contact with kids, she believes it's better to be safe than sorry.

"We were taking on workloads that are already huge and just piling way more on top of it so it has been like extremely helpful having those rapid tests," Solo said. "Just being able to you know swab and go. If you're clear, you can continue as normal if you're not, then you can get somebody to cover you but it's much less often that we need to cover each other now."

Most often, Solo gets her at-home test from local pharmacies but no matter how or when you take your coronavirus test, there are two different types. The Antigen test looks for protein that makes up the virus, and the PCR test amplifies nucleic acids within the virus.

"There are a lot of benefits to being able to test at home even though the tests are not the most sensitive of tests," said Dr. Ari Rao, chief medical officer and senior VP of pathology and lab medicine with Baylor Scott & White. "In these nucleic acid tests, we actually go through a process where that whole reaction amplifies the number of nucleic acids that we see."

Rao said the PCR is proven to be more accurate, but that there are times that antigen tests could come in handy if a person thinks they are asymptomatic or have symptoms. To accommodate for the lower sensitivity rate of the antigen test, Rao said to take the test multiple times.

"You test yourself today, you're negative, come back in 36 hours test yourself again, and then [take] maybe a third test," said Rao. "And say [in] 48 to 72 hours ... all three tests show that you're negative, then it's highly likely that you're really negative.

We also have rapid nucleic acid-based test, PCR tests as well ... one of the tests gives you in about 30 minutes. The other test takes about an hour. So those are also rapid, but the most common rapid tests that are available is the antigen test."

Rao said the rapid antigen tests are known to have false negatives; it's a fact Solo knows so she takes extra precautions every day.

"It's just kind of finding that balance between like 'yes, this test is one thing,' but it doesn't mean ... I'm negative so I can just you know, not wear my mask and not sanitize and just go about my day like normal," said Solo.

Rao encourages folks who are going to take those at-home tests to read all directions thoroughly just to make sure you're getting the most accurate result.