Rapid Tests for Coronavirus Raise Concerns Over Accuracy

by Marco Cáceres

Published June 28, 2020 | Business, Pharma

On Mar. 27, 2020, the U.S. Food and Drug Administration (FDA) issued Emergency Use Authorization (EUA) to pharmaceutical and medical devices company Abbott Laboratories, Inc. of Abbott Park, Illinois for a rapid diagnostic test for the SARS-CoV-2 virus known as ID NOW.^{1 2 3} “We know how important it is to get point-of-care tests out in the field quickly. These tests that can give results quickly can be a game changer in diagnosing COVID-19,” FDA commissioner Steve Hahn said.¹

Abbott’s ID NOW test is a portable device that weighs 6.6 pounds and is about the size of a toaster. At the time it was granted the EUA, Abbott had approximately  18,000 ID NOW devices in the United States and the company said it planned to manufacture more so that it could provide 50,000 tests per day. According to Abbott, ID NOW can deliver “positive results in as little as five minutes and negative results in 13 minutes.”^{1 2 3}
“The COVID-19 pandemic will be fought on multiple fronts, and a portable molecular test that offers results in minutes adds to the broad range of diagnostic solutions needed to combat this virus,” Abbott president and CEO Robert Ford said. “With rapid testing on ID NOW, healthcare providers can perform molecular point-of-care testing outside the traditional four walls of a hospital in outbreak hotspots.”^{2 3}
The FDA also granted SARS-CoV-2 rapid test EUAs to Cepheid, Inc. of Sunnyvale, California for its Xpert Xpress test and Mesa Biotech, Inc. of San Diego, CA for its Accula test .^{1 2 4 5 6}
The idea behind the increased reliance on rapid tests is that enables significantly more coronavirus testing of the population. Not only do these tests allow results to be available within half an hour, they can be administered in a wider variety of health care settings, including doctor’s offices. The more traditional tests for SARS-CoV-2 that are sent off to labs for evaluation take between 24 to 48 hours to obtain results.⁷

Rapid Tests May Provide False Sense of Security

The rapid tests are faster and more convenient. Joe Petrosino, PhD, chair of molecular virology and microbiology at Baylor College of Medicine, compares to going to eat at a “fast food chain” or a “gourmet restaurant.”⁷
The problem with the rapid tests, however, is that they’re not nearly as reliable as the tests sent to labs for processing. While most of the PCR (polymerase chain reaction) lab tests that take a couple of days to evaluate are more than 90 percent accurate, the rapid tests can be less than 80 percent accurate.⁷
The relative inaccuracy of the rapid tests means that these tests may be giving people who get them a false sense of security.
Dr. Petrosino cautioned:

I don’t think there’s a lot of awareness about the differences between rapid tests and the more traditional lab, send it out, 24 to 48 hour results type tests. It’s very important to know the difference. If you go to a rapid clinic and come out with a negative result, you think you’re okay and you could be exposing and putting a lot of individuals at risk.⁷

“There’s no way I would be comfortable missing two out of 10 patients,” said Susan Whittier, PhD, director of clinical microbiology at NewYork-Presbyterian/Columbia University Medical Center.⁸

FDA Warns of Inaccuracy of Abbott’s Rapid Test

On May 14, 2020, the FDA issued a warning to the public regarding the inaccuracy of Abbott’s ID NOW test. The warning began: “Today, the U.S. Food and Drug Administration is alerting the public to early data that suggest potential inaccurate results from using the Abbott ID NOW point-of-care test to diagnose COVID-19. Specifically, the test may return false negative results.”^{9 10}
“We are still evaluating the information about inaccurate results and are in direct communications with Abbott about this important issue. We will continue to study the data available and are working with the company to create additional mechanisms for studying the test,” said Tim Stenzel, MD, PhD of the FDA’s Center for Devices and Radiological Health.^{9 10}
In a study conducted by researchers at New York University, the ID NOW test missed more than 48 percent of the SARS-CoV-2 samples found to be positive by Cepheid’s Xpert Xpress test. Based on this finding, ID NOW may be missing about half of the positive cases of the virus.¹¹
A total of 3.7 million ID NOW tests have reportedly been delivered to all 50 states in the country.¹²

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