Abbott (NYSE:ABT) said today that its ID NOW COVID-19 test works better on specimens collected soon after patients begin showing symptoms.
The test’s performance has drawn fire from federal officials in recent weeks, including a recent FDA warning that the ID NOW test may return false-negative results. The agency granted the test an emergency use authorization (EUA) on March 27 and said it is now investigating whether false-negative results could be due to the types of swabs used or the type of viral transport media.
Abbott began advising customers in mid-April that ID NOW is a rapid test that was not designed for use with viral transport media. The company also recommended using dry nasal swabs to collect samples.
Today, the company announced an interim analysis of an ongoing clinical study at five urgent care clinics in New Jersey, Tennessee, Louisiana, Texas and South Carolina. The analysis shows the test produces results that are largely comparable to to those performed on lab-based molecular polymerase chain reaction (PCR) instruments.
Specifically, the urgent care clinic study shows ID NOW’s positive test results agree with those produced by PCR instruments ≥94.7% of the time (indicating sensitivity), and its negative test results show a ≥98.6% negative agreement (specificity) when compared to two different lab-based PCR reference methods, the company said in a news release.
In 256 subjects enrolled to date in the urgent care clinic study, ID NOW has identified 29 of 29 positive samples (100% positive agreement) and 226 of 227 negative samples (99.6% negative agreement) when compared to a commonly used lab-based molecular PCR assay (the Roche Cobas SARS-CoV-2 assay). In these subjects, the mean number of days from symptom onset is 4.1 days with 90% of subjects tested within 7 days post-symptom onset, when patients typically show up for care, Abbott noted.
ID NOW has also demonstrated 94.7% positive agreement and 98.6% negative agreement compared to the Centers for Disease Control (CDC) 2019-Novel Coronavirus (COVID-19) real-time RT-PCR diagnostic panel. In comparison, Roche has demonstrated 95.0% positive agreement and 98.7% negative agreement when compared to the CDC assay.
This is one of the first studies conducted on the ID NOW COVID-19 test in a real-world setting as it is intended to be used, compared with other studies that have used banked or retained samples, according to Abbott.
Data from this, as well as two other Abbott-sponsored studies — one by The Everett Clinic in Washington and an ongoing study of hospitalized and nursing home patients — suggest ID NOW performs best in patients tested soon after developing symptoms, when they are most likely to go for care, according to Abbott. In these studies, ID NOW was used as intended with variations in patient populations based on the number of days a patient was tested after first experiencing symptoms, the company said.
The Everett Clinic study involved 955 subjects (763 symptomatic and 192 asymptomatic) and showed 91.3% positive agreement and 100% negative agreement.
The ongoing study of hospitalized and nursing home patients tested with late symptom onset shows ≥83.3% positive agreement and ≥96.5% negative agreement when compared to Hologic’s Panther Fusion SARS-CoV-2 test. ID NOW has shown 85.7% positive agreement and 97.6% negative agreement compared to the CDC assay, while the Hologic assay has demonstrated 91.8% positive agreement and 98.2% negative agreement when compared to the CDC assay, according to Abbott.
In an interim analysis of the hospital and nursing home study, the mean number of days from symptom onset is 12.2 days with more than 68% presenting with ≥8 days post-symptom onset. In comparison, the Everett study mean was 9.7 days post-symptom onset and the urgent care clinic at 4.1 days post-symptom onset.
Data from these studies suggest ID NOW performs best in people tested earlier after they first begin experiencing symptoms, according to Abbott. This is consistent with a recent study published in the Annals of Internal Medicine, in which researchers from the Johns Hopkins School of Public Health found that even the most sensitive lab-based molecular tests can have false negatives when viral load levels are ramping down and patients may no longer be infectious.
Abbott said it will report full results from these studies when the studies and analyses are completed.
“We’re pleased that 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 Dr. Philip Ginsburg, senior medical director, infectious disease, for Rapid Diagnostics at Abbott. “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.
“These new interim results reflect what we’re hearing from hundreds of our customers, which is that they’re seeing results with positive rates from ID NOW that are at, or above, their local COVID-19 infection rates,” Ginsburg added. “This tells us that ID NOW is performing comparable to molecular laboratory tests in detecting the virus.”
