When Can You Trust At-Home COVID-19 Tests?

The general consensus among independent experts is that these tests only make sense in very specific circumstances.  

MIAMI LAKES, FLORIDA – JULY 22: Dr. Jacqueline Delmont, Chief Medical Officer of SOMOS Community Care, uses a nasal swab to test Eddie Mena for COVID-19 in a medical tent at a testing site locate at the Miami Lakes Youth Center on July 22, 2020 in Miami Lakes, Florida. Testing is being provided by doctors from New York City associated with SOMOS Community Care, as the state of Florida experiences a surge in coronavirus cases. Joe Raedle/Getty Images

Last month, the pharmaceutical company Moderna announced the results of a new study of its COVID-19 vaccine. While it worked well on the new strain of the virus initially found in the UK, the company said that it would likely need to develop a new variation of its vaccine to effectively combat the mutated strain initially found in South Africa. The entirety of the pandemic has been a race against time—a race that governments continue to lose.

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As the U.S. death toll reaches 442,000, more than the entire population of Minneapolis, President Joe Biden is focused on ramping up the lagging distribution of the various vaccines now available. But to slow the spread of the virus and begin to approach normalcy, the country is also in desperate need of improved and more robust testing options. Complications abound here, too.

The new tests are all meant to be administered at home. These tests fall into two categories: mail-in tests and self-administered rapid tests. There are at least four mail-in tests already on the market. Some of the biggest players in the space include Everywell, Quest Diagnostics, empowerDx and Labcorp. At least two companies will soon have at-home rapid tests available to consumers: Australia-based Ellume, and Lucira Health. Another major player in the space, Abbott Pharmaceuticals, just launched their at-home test which is now available for purchase.

How The Tests Work

The Abbott test connects to an app that the company developed with eMed, an at-home testing company. Approved by the FDA through an Emergency Use Authorization in December, the app—dubbed NAVICA—vets the patient’s eligibility for a test. If they’re met, the company ships users a test.

Once the test arrives, patients connect with a medical professional who will walk them through the process. The results are determined through a test card included in the kit. Users add an extraction reagent and a nasal swab is taken from each nostril to the card and fold it. Abbott says patients will get results in 15 minutes and expects to deliver 30 million of these tests in the first quarter of the year.

Ellume will operate in a similar way, but with an extension added to smartphones. Also approved by EUA in December, patients use a nasal swab, a dropper, processing fluid to test for COVID-19. The analyzer connected via Bluetooth which connects to an app. The company asserts users will have results within 15 minutes. It’s not clear exactly when Ellume will be available to consumers. “Ellume is in the process of determining a phased roll-out plan with the goal of mobilizing tests as quickly as possible,” a company spokesperson tells Observer.

Lucira Health will soon come out with a molecular test kit that they assert will come up with results in 30 minutes. This test received an FDA Emergency Use Authorization in November. It uses a nasal swab and a device that will alert users with the results, which are indicated by blinking lights. This test is not yet on the market but the company hopes to have it available in the coming months.

See Also: A Third At-Home Coronavirus Test Was Just Approved. Here’s How to Get One.

Everywell’s test is analyzed in a lab. A patient, once approved for a test, is mailed a self-administered via a nasal swab. Consumers must swab the front of the nostril about 1 inch deep. This test is a PCR test. Users must mail their collection to their labs; results come within 24-48 hours. Quest Diagnostics, LabCorp, and empowerDX have comparable products.

When Do The Tests Work?

While these companies assert high accuracy rates, independent physicians who spoke to Observer approach these tests with a level of skepticism. In particular, they have concerns over accuracy specifically for asymptomatic people.

“One of the things that I found the most striking reading through the Emergency Use Authorization [EUA] for a lot of these tests is that they were trialed only on symptomatic patients,” said Dr. Valerie Fitzhugh, Associate Professor, and Interim Chair for the Department of Pathology at Rutgers University. “The issue that I see since there haven’t been as many trials on asymptomatic patients is how accurate can the test be on someone who has no symptoms?”

Dr. Edward Hoffer, Associate Professor of Medicine at Harvard Medical School, echoes Fitzhugh’s sentiment. “The quick tests do have a place in our armamentarium and one of the concerns is about the accuracy because most of them have been approved based on very small studies,” he tells Observer.

The FDA’s Healthcare Provider fact sheet for the Labcorp At Home COVID-19 test validates Fitzhugh’s concerns. “Asymptomatic people infected with COVID-19 may not shed enough virus to reach the limit of detection of the test, giving a false negative result,” the HCP sheet says.

Abbott also acknowledged that continued study is needed for asymptomatic people.

“Other independent third-party studies have identified that higher CT (cycle threshold) counts are correlated with a lack of infectiousness, and a rapid antigen test with high performance at a CT count of 33 or below is able to detect the virus in people who are infectious. Abbott continues to study the BinaxNOW COVID-19 Ag Card, including in asymptomatic people,” the company said in a release in December regarding its EUA.

“We are not seeing the EUA’s get cleared on asymptomatic patients because it is really challenging to do a study like that and get enough people into your bucket to have a robust enough data set to submit,” Dr. Amanda Harrington, Associate Professor and Vice-Chair for Clinical Pathology at Loyola University Chicago tells Observer.

See Also: Airlines and Supermarkets Try to Save COVID-19 Testing From Its Disaster State

Meanwhile the FDA, in the EUA, points out that this antigen test, like antigen tests in general, has an increased risk of false-negative results. “Antigen tests are very specific for COVID-19, but are not as sensitive as molecular PCR tests. This means that there is a higher chance of false negatives than with many molecular tests. Positive results from antigen tests, while generally highly accurate, may be subject to false-positive results especially in areas where there are fewer infections,” the EUA reads.

“Part of why we need some healthy skepticism is because the average consumer may not understand the differences between those tests,” Dr. Harrington says. “We know PCR may perform better than antigen but the consumer may not understand the difference between a negative on one test and a negative on another. I worry that they see a negative as a negative and they see that as a license that you are now free to move about.”

As a result, the general consensus among independent experts is that these tests only make sense in very specific circumstances.

“The at-home tests should be a bridge for certain regions of the country that are possibly more rural and they don’t have, within a few mile radius, facilities to go to for testing and for assessment,” Dr. Alexander Salerno, primary care physician at Salerno Medical Associates, who has treated thousands COVID-19 patients to date, tells Observer. “That would be the limited scope I could see of value.”

The pharmaceutical companies acknowledged that challenge while simultaneously pointing that, to an extent, these tests take some burden off of overwhelmed hospitals especially in hard-hit areas or regions without a major medical center.

“An at-home test is useful if where you live does not have readily available testing, or you are asymptomatic and your local testing facilities require multiple symptoms to get a test. In general, home testing helps avoid spread and reduce the burden on strained medical facilities,” Sean Parsons, CEO and Founder of Ellume tells Observer.

Abbott expressed a similar sentiment.

“Our goal for an at-home test was to both increase access to testing and support people’s confidence in testing at home. The eMed offering could also remove some of the obstacles that individuals, governments and organizations face when looking to provide or perform testing,” Dr. Mary Rodgers, principal scientist in Abbott’s diagnostics business, tells Observer. “These include mobility issues for people with disabilities or who may not have a reliable form of transportation, inconvenient testing windows for people who work non-traditional hours or have childcare or eldercare responsibilities.”

Still, the tests do remove a huge burden from the breaking backs of healthcare providers and hospitals. “The authorization of a COVID-19 at-home collection kit that can be used with multiple tests at multiple labs not only provides increased patient access to tests, but also protects others from potential exposure,” Dr. Jeffrey Shuren, director FDA’s Center for Devices and Radiological Health, said in a statement in response to the Everywell test.

One of the challenges leaves room for human error with additional variables that can be avoided if tests are administered directly by doctors. “The effectiveness of the person following the instructions and getting a proper specimen,” Dr. Salerno says.

“These are the kind of things you have to follow to the letter to get as accurate results as possible,” Dr. Fitzhugh adds.

When Should You Use Them? And How?

Elected leaders have provided confusing information that often undermines the science. As the Center For Public Integrity reported in November, the Trump White House pushed governors around the country to use rapid tests like the Abbott test for asymptomatic people. This was despite concerns from both scientists and state-level public health officials.

Abbott itself says these tests need to be studied further with asymptomatic people.

“I always worry that these tests are misused or misinterpreted. We know that they’re not perfect. I am concerned that people think a negative is a negative,” Dr. Harrington says. “We’ve seen too many cases where someone tested negative in the morning and went about their business and they just didn’t know they were presymptomatic below that threshold. This is a tool that is positive and can be really effective.”

“If you are symptomatic and you do an at-home test and test negative for COVID you need to actually confirm it with another test,” Dr. Fitzhugh says, adding that “a positive test gives you a very good probability that you have COVID but a negative test doesn’t exclude it.”

Abbott admits more studies need to be done on the at-home tests’ ability to find the virus in asymptomatic people. Everywell is trying to circumvent those problems.

“We’ve invested a lot of time, resources, and effort into educating regular people at home properly,” Dr. Frank Ong, Chief Medical Officer for Everywell tells Observer. They’ve had a lot of practice teaching testing literacy. Everywell creates tests for a wide range of issues including fertility, colon cancer, and STDs among others.

Then there is the human factor, including elected officials who disregard science, consumer testing literacy, and how people react to good news versus bad news.

“This is a good step in the right direction. Is it perfect? No, but perfection is the enemy of good,” Dr. Hoffer says.

When Can You Trust At-Home COVID-19 Tests?