The Country's Top Doctors Are Pushing for "Less Accurate" COVID Tests
According to these top doctors, faster, less accurate antigen tests for COVID are a worthwhile trade-off.
You've likely heard by now that coronavirus testing is so backed up, it's taking one to two weeks for people to get their results back. Not only is this frustrating for those wondering if they're sick, but it's also a public health issue, as potentially contagious people could be assuming they're fine and going about their regular business. Now, two of the country's top doctors are advocating for some immediate course correction when it comes to coronavirus testing. These experts are pushing for a new approach that prioritizes a higher volume of testing with speedier results over accuracy. "We have to start accepting less accurate, widespread testing," the director of the Center for Health Policy and Professionalism Research, Aaron Carroll, MD, wrote in a new op-ed for The New York Times. "More is sometimes better than perfect."
At the beginning of the pandemic, experts' first instinct was to employ tests with the most accuracy, which led to PCR tests being the most widely used. These tests are done through a nasal swab and usually takes one to 7 days to get results, according to the Food & Drug Administration (FDA). The other kind of tests, antigen tests, can be done via saliva, even by people at home. And they take under an hour to get results, the FDA says.
While antigen tests are cheaper and faster, they're less accurate than PCR tests—but not by much. Experts say they are 93 percent accurate compared to the PCR test's 99 percent accuracy, according to a recent Today report.
So, why recommend antigen tests suddenly? Well, many public health officials say test results that don't come back within 48 hours don't serve their purpose. "If you don't know if that person gets the results back at a period of time that's reasonable—24 hours, 48 hours at the most—when you get to six or seven days, that kind of really mitigates against getting a good tracing and a good isolation," Anthony Fauci, MD, said in a recent appearance on CNN.
So, according to Carroll and Ashish Jha, MD, director of the Harvard Global Health Institute (HGHI), the slightly increased accuracy of PCR tests is not worth the problems delayed test results are causing.
In his Times op-ed, Carroll compares America's approach to masks to the COVID-19 testing issues. When masks first became a suggested precaution, the public zeroed in on N95 masks because they are considered the most effective. However, not everyone could access them and the Centers for Disease Control and Prevention (CDC) actually started discouraging the American public from buying N95 masks so that the supply could be reserved for those on the frontlines. N95 masks are known to block 95 percent of potentially contaminated particles (hence their name), while standard homemade double-layer cotton masks block up to 80 percent of particles.
Carroll points out that having everyone wearing less effective masks is more beneficial than having a small portion of people wearing highly effective masks. So, he says this is the same logic we should apply to testing. If the majority of people have access to inexpensive, rapid testing, that's more useful than a smaller group of people taking tests and waiting over a week for results.
Similarly, in an op-ed for Time, Jha says, "The way forward is not a perfect test, but one offering rapid results." According to Jha, PCR tests are too expensive and slow to be of much practical use. In his mind, the solution to this issue is antigen tests that could be taken frequently at home. "Imagine spitting on a special strip of paper every morning and being told two minutes later whether you were positive for COVID-19," says Jha.
Some have argued that it would be irresponsible to rely on testing that could miss a significant number of positive cases. However, Jha says that the frequency and speed antigen tests afford offset that concern. "The PCR tests are currently slowing laboratories to a crawl. If everyone took an antigen test today—even identifying only 50 percent of the positives—we would still identify 50 percent of all current infections in the country—five times more than the 10 percent of cases we are likely currently identifying because we are testing so few people," writes Jha.
When it comes to the debate between accuracy and speed, both Jha and Carroll heartily advocate for the latter. "By putting a premium on the accuracy of tests, we fail to test a majority of people with COVID-19," Jha writes. "These built in delays actually undermine our ability to timely identify cases which is the key purpose for widespread testing." And for another group of experts pushing back against the most common COVID-19 test out there, check out The Surprising Reason Behind the Most Recent Major CDC Guideline Change.