PROVIDENCE, R.I. (WPRI) — Researchers at the Cleveland Clinic are raising questions about the accuracy of a rapid coronavirus test which is being used at one of Rhode Island’s testing sites.
The researchers found a 14.8% rate of false negatives with the Abbott ID NOW system in tests of samples known to have COVID-19, according to NPR, which first reported the results.
Dr. Gary Procop, who led the research, told NPR the results led the prestigious hospital to stop using the Abbott ID NOW test on patients altogether. The doctor also said the hospital would stop using the DiaSorin Simplexa test, which they found had about a 10% rate of false negatives.
The Abbott test garnered a lot of excitement when it was first unveiled by President Donald Trump at a news conference in March, in part because it can provide results in minutes by placing the swab directly into the Abbott machine.
Other COVID-19 tests are sent to labs to be processed, and can take several days to get results.
Rhode Island’s testing capacity doubled overnight earlier this month with the introduction of the Abbott ID NOW test at the CVS drive-through testing site at Twin River Casino in Lincoln, where the health department has said about 1,000 tests can be done per day.
Another approximately 1,000 tests are done at other sites in Rhode Island including the state colleges, hospitals and respiratory clinics. Those tests use the traditional method of processing at a lab, while the CVS site is able to give patients’ their results while they wait in their cars.
Asked about the Cleveland study on Tuesday, R.I. Health Department Director Dr. Nicole Alexander-Scott said she was aware of the research, and emphasized that people with symptoms should stay home while sick — even if they test negative for COVID-19 — due to the possibility of a false negative.
“For all of the tests that we do on these specimens, it is most reliable and most accurate when it’s done on persons who have symptoms,” Alexander-Scott said. “That is a key, and that element decreases the risk of the false negative percentage.”
She added that the rapid tests from the CVS site were “verified” at the state’s health lab with “consistent results” when the tests were first rolled out. In a conference call with reporters after the briefing, she said there were fewer than 10 rapid tests from the CVS site that were re-tested at the state health lab. She did not provide an exact accuracy rate.
“It’s the best that we have,” Alexander-Scott said. “It’s an important way that we have been able to expand testing.”
Rhode Island has one of the highest testing rates in the country, and is the only state exceeding the per-capita threshold set by Harvard researchers when it comes to eventually reopening the economy.
Abbott has pushed back on the Cleveland Clinic research, arguing that the doctors used “viral transport media” to carry the samples, referring to a liquid commonly used to transport samples to labs.
“When the direct swab method is used, the test is performing as expected and we are confident in its performance,” the Abbott spokesperson said. She did not respond to a question about what the accuracy rate is with the direct swab method. (The test was authorized by the FDA in March for emergency use, but is not yet FDA approved.)
Abbott sent out a communication to customers on April 15 highlighting an issue with transporting the samples to lab for verification, saying it could lead to false negative results.
“ID NOW is designed for – and typically used within – urgent care clinics, physicians’ office labs, emergency departments, and retail settings,” the company statement said. “This means that patient samples (swabs) are collected and tested directly on the ID NOW instrument, near the patient and without the use of VTM.”
The spokesperson also pointed to an interview with a Northwestern doctor who said results improved at the hospital after physicians stopped carrying the samples up to the lab, instead running the tests directly in the emergency room.
Cleveland Clinic’s Dr. Procop told NPR the samples in his research were indeed stored in viral transport media before being tested, but he argued Abbott should release data proving that it has an accuracy rate higher than the 85% his study found.
“It is a risk that if you tell somebody they’re negative and they’re truly positive, that they will relax social distancing, not wear a face mask, et cetera, and could transmit the disease,” Procop told the radio network.
A spokesperson for the Cleveland Clinic said Dr. Procop was not immediately available for an interview with WPRI 12 because of an inundation of media requests. But she confirmed the numbers reported by NPR were accurate, adding that the hospital tested more than 200 specimens “head-to-head” among five different testing platforms.
The Abbott ID Now test had the highest false negative rate, followed by the DiaSorin Simplexa test. She said the less accurate tests could be used in areas with lower prevalence of the disease.