LetsGetChecked’s at-home Coronavirus (COVID-19) Test was recently put to the test by the Food and Drug Administration (FDA) - the United States Federal Agency responsible for ensuring the safety and security of a wide range of crucial products such as drugs, biological products, and medical devices.
FDA’s SARS-Cov2 reference panel strived towards comparing the analytical and clinical performance of a wide range of different tests - 81 to be exact. The FDA provided labs and manufacturers of COVID-19 tests a reference panel with the ultimate goal of helping healthcare providers and consumers compare and contrast the range of tests available on the market - with overall performance and sensitivity in mind.
How the FDA reference panel process worked
LetsGetChecked received the FDA Emergency Use Authorization for their COVID-19 home test in May 2020. The FDA delivered five tubes that contained both a heat-inactivated SARS-CoV-2 strain and a heat-inactivated MERS-CoV strain. The latter strain is included to ensure the test can differentiate between similar viruses - quite a common issue that can sometimes lead to a ‘false positive’ result. The concentration of viral particles in the tubes was only known by the FDA, and each participating lab used their test to measure the concentration and submitted their data to the FDA for review.
How the results were categorized
The FDA’S reference panel results were split into three different categories - the three different types of diagnostic tests seen to reliably indicate the presence or absence of the current SARS-CoV-2 infection.
The three distinct test categories examined by the FDA included:
Swabs in transport media: These include upper nasal (nasopharyngeal), lower nasal, and/or throat swabs (oropharyngeal) that are transported to the laboratory for testing in transport media (solutions of buffers to preserve bacteria during transport). This was the largest category with 76 different tests examined.
Direct swabs: These refer to upper nasal (nasopharyngeal), lower nasal, and/or throat swabs (oropharyngeal) that are transported to the laboratory for testing without being submerged in liquid. There were two tests in this particular category.
Saliva tests: In this test, the patient’s saliva is tested - there were three tests in this category.
As established by the FDA’s reference panel, the LoD (limit of detection) of the saliva tests and dry swabs are orders of magnitude higher than swab tests - this means that there must be more virus present for the saliva and dry swab test to be detected as positive.
Where LetsGetChecked ranked
The LetsGetChecked at-home Coronavirus test features a nasal swab and so was categorized in the first category - ‘swabs in transport media’; the largest categories out of three.
LetsGetChecked’s test ranked highest for both lower nasal swab tests, and take-home tests and came in 10th overall out of a total of 81 tests from all three categories.
Tests are ranked by their LoD, which is a measure of test (analytic) sensitivity. A low limit of detection is ideal - this means a test can detect even the smallest amount of the virus, it also means there is a smaller risk of a false negative result.
More information on the results can be found here.
Developers for a total of 165 FDA authorized tests currently available on the market were contacted to participate in the reference panel, but for various reasons, all were not able to participate. For this reason, not all tests available on the market are included in the results of this FDA reference panel.