At-Home COVID-19 Test Comparable to Clinic Test, Study Finds

The Food and Drug Administration (FDA) relaxed restrictions on at-home COVID-19 testing this week, allowing companies to create and submit an emergency use authorization to enable people to test themselves at home.

"These types of tests will be a game-changer in our fight against COVID-19 and will be crucial as the nation looks toward reopening," FDA Commissioner Stephen Hahn said in a statement.

The announcement comes on the heels of a July 22 study that found at-home COVID-19 test kits had comparable results to COVID-19 tests conducted at a doctor’s office. The study, published in JAMA, recruited 185 people—mostly healthcare workers—who either visited a drive-through testing site or already had a positive test result for SARS-CoV-2, the virus that causes COVID-19. Of that group, 41 had positive test results from either a nasopharyngeal swab taken from a medical provider, a home self-collected mid-nasal swab, or both.

The researchers found that the sensitivity of at-home swabs was 80%, while the specificity was 98%. There were seven false negatives among those who used at-home testing, the researchers found, although these typically happened people waited an average of six days after symptom onset to take a test.

The study’s authors point out the advantages of at-home testing, including accessibility and the minimized need for personal protective equipment (PPE).

“This approach is safe and scalable in the pandemic setting, permitting widespread testing of symptomatic participants early in illness and the potential for prompt self-isolation and contract tracing,” the study’s authors wrote.

How Accurate Are At-Home Tests for COVID-19?

There are several at-home tests for COVID-19 on the market, and the effectiveness of each varies. In this particular study, the tests were about 80% accurate at detecting COVID-19 when someone had the virus. That’s comparable, but not quite as good, as tests that are performed by a medical provider. An article published in Mayo Clinic Proceedings says that tests performed by a medical provider are up to 90% accurate. 

How Does At-Home Testing for COVID-19 Work?

Participants in the JAMA study were asked to do a mid-nasal swab, which is different from the nasopharyngeal swab that is typically taken at a doctor’s office or drive-through clinic.

“Basically, it’s just how high into the nose the swab is pushed,” Susan Besser, MD, a primary care physician at Mercy Personal Physicians at Overlea in Maryland, tells Verywell. “A mid-nasal swab is just into the nose; the nasopharyngeal swab is much further back—to the very back of the nose where the passage connects with the throat.”

Using a mid-nasal swab is “essentially just like picking your nose with a Q-tip,” David Cutler, MD, a family medicine physician at Providence Saint John’s Health Center in Santa Monica, California, tells Verywell. “You go in an inch and rotate the swab three times against the inside of the nose."

With a mid-nasal swab, it’s important to insert the swab “at least far enough in to get it moist,” Cutler says.

While nasopharyngeal swabbing is the primary method of testing for COVID-19, the Centers for Disease Control and Prevention (CDC) says that mid-nasal swabs are effective as well. It’s not unusual for patients to do this on themselves; Cutler says he’ll have his patients perform a mid-nasal swab test in an exam room in his office on their own to avoid exposing himself and his co-workers to potential aerosols generated from the test. 

Once a swab is taken, it’s immediately placed into a sterile transport tube and shipped to a lab for testing. 

How Can You Test Yourself Accurately and Safely?

To get an accurate reading with an at-home test, Besser recommends swabbing both sides of your nose. “Try to get as far back as you can, without making yourself too uncomfortable,” she says.

And, while it’s not common for people to injure themselves while collecting a swab, Besser recommends going slow and being gentle when you do a nasal swab. “Don’t ram it in,” she says.

Once you take your swab, it’s important to make sure that the lid of the transport tube is on tight. “The virus will dry out on transport otherwise,” Cutler says. 

What Are the Limitations of At-Home Testing?

The JAMA study authors pointed out that there are limitations to at-home testing, including:

• Damage while in-transit. There is a possibility that the samples could be damaged or degraded during shipping before they can be tested
• The timing of when the test is taken. In this study, home samples were often taken a day after patients were tested by medical providers. During that time, the patients’ viral load could be lower, potentially making it more difficult to get an accurate reading. One study published in the Annals of Internal Medicine in May found that test timing is crucial to getting an accurate result, not matter what type of test you take, noting that testing within three days of symptom onset is crucial.
• The ability to get an accurate sample. In this study, many participants were healthcare workers and were familiar with how to accurately perform this type of test.

“A home-based strategy should be targeted toward individuals early in illness, when risk of transmission is highest and care seeking less likely,” researchers say.

Cutler is particularly concerned about the false negative results. Several people in this particular study received false negative results, and those people likely stopped isolating after they tested negative, potentially spreading the virus to others, he says. But, he says, this is an issue with testing through a medical provider, too.

“Even the best tests aren’t perfect. We already know we’re missing some of these cases,” Cutler says. 

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.