FDA raised concerns Monday about an increased rate of false positives associated with a BD test for the novel coronavirus.
In a letter to healthcare professionals, the agency said 3% of results in one study run by the company were false positives. BD received emergency use authorization from FDA in April following a study that found the test concurred with expected results 100% of the time.
- FDA's alert concerning reagents for the BD Max System is the first time during the public health emergency that FDA has issued a public letter to healthcare providers about the accuracy of a specific company's test for the coronavirus.
BD said in April it based its COVID-19 molecular diagnostic on the Centers for Disease Control and Prevention test, which faced its own problems early in the coronavirus outbreak. The work resulted in a test designed to run on the thousands of BD Max units installed at hospital laboratories and other sites around the world, delivering results within three hours.
With each BD Max unit being able to analyze hundreds of samples a day, the EUA set the stage for a significant scaling up in COVID-19 testing capacity. In May, BD said its current footprint supported the production of 1 million tests per month.
Now, FDA has raised concerns that some of those tests may deliver false positives, leading providers to erroneously believe some patients are infected with the coronavirus. The agency told healthcare professionals to treat positive results from tests using the BD reagents as “presumptive” and consider confirming findings using a different authorized coronavirus diagnostic.
BD in an email statement to MedTech Dive said it has received reports of elevated rates of potential false positive results from certain customers experiencing the issue when using the the company's SARS-CoV-2 reagents for the BD MAX system. The company said it has approached FDA and provided options for improving the performance of the BD SARS-CoV-2, including information required to support the changes.
While the FDA letter to healthcare professionals is the first of its kind in response to the COVID-19 crisis, it is part of a series of alerts issued by the agency regarding the accuracy of coronavirus tests.
For instance, FDA put out a statement in May about the accuracy of Abbott’s ID NOW test. In that case, FDA responded to a study that linked ID NOW to a higher rate of false negatives than rival COVID-19 tests with a statement about “potential inaccurate results.” Abbott changed its sample collection and handling instructions and agreed to conduct postmarket studies to address the concerns about the rate of false negatives.
FDA has also previously sent a letter to healthcare professionals recommending against the use of certain antibody tests, and issued a similar notice about safety risks associated with the use of some molecular transport media.
The letter regarding BD's reagents comes on the heels of a positive development for the company. On Monday, FDA granted an EUA to a BD antigen test designed to deliver results within 15 minutes at the point of care, making it only the second such diagnostic to receive a nod from the agency. A Quidel test claimed the antigen category's first EUA in May and also delivers results in 15 minutes.
Both molecular and antigen tests are capable of diagnosing active coronavirus infections. But while FDA considers molecular tests quite accurate, the agency says healthcare providers may consider ordering a molecular test following an antigen test to confirm its results.