Though the test initially drew ‘raves’ from Trump administration, the FDA now suggests negative results should be confirmed with an additional ‘high-sensitivity authorized SARS-CoV-2 molecular test’
This spring, as the United States attempted to jump-start a national response to the SARS-CoV-2 coronavirus pandemic, the Trump administration heralded Abbott Laboratories’ five-minute test for COVID-19 as a major breakthrough. But even as the federal Food and Drug Administration (FDA) issued dozens of Emergency Use Authorizations (EUAs) to quickly get COVID-19 diagnostic tests into clinical use, the accuracy of some of those tests came into question—including Abbott’s ID NOW COVID-19 rapid molecular test.
The continuing controversy over Abbott’s ID NOW COVID-19 test shows how the national spotlight can be a double-edged sword, bringing both widespread favorable attention to a breakthrough technology, followed by heightened public scrutiny if deficiencies emerge. At the same time, from the first news stories about the Abbott ID NOW COVID-19 test, pathologists and clinical laboratory managers understood that this test always had certain performance parameters, as is true of every diagnostic test.
“Everybody was raving about it,” a former administration official, speaking on the condition of anonymity to discuss internal deliberations, said of ID NOW in an interview with Kaiser Health News (KHN). “It’s an amazing test, but it has limitations which are now being better understood.”
FDA Warns Public about Inaccurate Test Results
On May 14, the FDA issued a public warning about the point-of-care test’s accuracy after receiving 15 “adverse event reports” indicating some patients were receiving “false negative results.”
The FDA’s public alert followed a New York University (NYU) study, published in the Journal of Clinical Microbiology, titled, “Performance of Abbott ID Now COVID-19 Rapid Nucleic Acid Amplification Test Using Nasopharyngeal Swabs Transported in Viral Transport Media and Dry Nasal Swabs in a New York City Academic Institution,” which compared Abbott’s ID NOW COVID-19 test results to those from the Cepheid Xpert Xpress SARS-CoV-2 rapid near-patient test, which NYU had already been using in its laboratory.
“Regardless of method of collection and sample type, Abbott ID NOW COVID-19 had negative results in a third of the samples that tested positive by Cepheid Xpert Xpress when using nasopharyngeal swabs in viral transport media and 45% when using dry nasal swabs,” the NYU study authors stated.
Abbott Rebuts Criticism
In a statement following the FDA’s warning, Abbott said, “We’re seeing studies being conducted to understand the role of ID NOW in ways that it was not designed to be used. In particular, the NYU study results are not consistent with other studies. While we’ve seen a few studies with sensitivity performance percentages in the 80s, we’ve also seen other studies with sensitivity at or above 90%, and one as high as 94%.
“While we understand no test is perfect, test outcomes depend on a number of factors including patient selection, specimen type, collection, handling, storage, transport and conformity to the way the test was designed to be run. ID NOW is intended to be used near the patient with a direct swab test method,” Abbott’s statement added, noting the company would be “further clarifying our product information to provide better guidance” and “reinforcing proper sample collection and handling instructions.”
Then, on May 21, Abbott issued another statement highlighting an interim analysis of an ongoing multisite clinical study demonstrating ID NOW COVID-19 test performance is ≥94.7% in positive agreement (sensitivity) and ≥98.6% negative agreement (specificity) when compared to two different lab-based molecular PCR reference methods.
“We’re pleased ID NOW is delivering on what it was designed to do—quickly detect the virus in people who need to know now if they’re infected,” said Philip Ginsburg, MD, SAIM, Senior Medical Director, Infectious Disease, Rapid Diagnostics at Abbott, in the statement. “This is great news for people who are experiencing symptoms and want to take action before they infect others, reducing the spread of infection in society.”
Nonetheless, KHN reported on June 22 that the FDA had “received a total of 106 reports of adverse events for the Abbott test, a staggering increase. The agency has not received a single adverse event report for any other point-of-care tests meant to diagnose COVID-19.”
Second Comparison Study Results for Abbott’s ID NOW
Susan Whittier, PhD, Director of Clinical Microbiology at New York-Presbyterian/Columbia University Medical Center, co-authored a study, published in Science Direct, titled, “ Comparison of Cepheid Xpert Xpress and Abbott ID NOW to Roche cobas for the Rapid Detection of SARS-CoV-2,” which compared Abbott ID NOW and rival Cepheid Xpert Xpress SARS CoV-2 to the Roche cobas SARS-CoV-2 assay for samples with low, medium, and high viral concentrations.
The Abbott ID NOW test correctly identified 74% of positive samples. In comparison, Cepheid’s Xpert Xpress SARS CoV-2 test correctly identified 99% of positives. Negative agreement was 100% and 92.0% for ID NOW and Xpert, respectively.
The FDA’s testing policy for clinical laboratories and commercial manufacturers recommends diagnostic tests correctly identify at least 95% of positive samples. However, KHN pointed out, a senior FDA official in late May said coronavirus tests that were administered outside lab settings would be considered useful in fighting the pandemic even if they miss 20% of positive cases.
“There’s no way I would be comfortable missing two out of 10 patients,” Whittier told KHN.
Abbott ID-NOW’s Role in the Global Fight to Stop COVID-19
However, in the FDA’s initial public warning, Tim Stenzel, MD, PhD, Director of the Office of In Vitro Diagnostics and Radiological Health, part of the FDA’s Center for Devices and Radiological Health, said, “This test can still be used and can correctly identify many positive cases in minutes. Negative results may need to be confirmed with a high-sensitivity authorized molecular test.”
Abbott’s ID NOW COVID-19 test is promoted as delivering positive test results in five minutes and negative results in about 13 minutes. On its website and in news releases, Abbott maintains its test “performs best in patients tested earlier post symptom onset.”
In a July 17 statement, Abbott said, “ We have shipped 5.3 million of our rapid ID NOW tests to all 50 states, Washington DC, Puerto Rico and the Pacific Islands. The majority of these tests have been sent to outbreak hotspots and we’ve asked that customers prioritize frontline healthcare workers and first responders.”
It is common for a new diagnostic instrument and a new clinical laboratory test to be continually improved after initial launch. Thus, the performance of such devices at the time they are given clearance from the FDA to be used in clinical care can be much improved several months or years later.
Given the importance of a reliable point-of-care SARS-CoV-2 test during the pandemic, it can be assumed that Abbott Laboratories is working closely with its medical laboratory customers specifically to improve the accuracy, reliability, and reproducibility of both the instrument and the test kit.
—Andrea Downing Peck