SAN FRANCISCO, Calif. (KRON) – While the FDA says at-home coronavirus tests may be less sensitive to the omicron variant, doctors and researchers here in the Bay Area say that’s not necessarily the case.
They say the at-home antigen tests are still an important tool and produce mostly accurate results.
As at-home COVID-19 antigen tests fly off the shelves at your local stores, some people are now questioning their accuracy in detecting the omicron variant.
Some doubts have been raised after the FDA put out this report on Tuesday writing: “Early data suggest that antigen tests do detect the omicron variant but may have reduced sensitivity.”
“FDA didn’t do any favors to anybody today by reporting out sensitivity. What they should’ve been reporting out is negative predictive value which is a different cut when you array this in a two-by-two table when you have a negative test how sure can you be that it’s negative, truly negative and the answer is when there’s 45 cases per 100,000 in San Francisco for example, the vast majority, 99% are going to be true negatives,” Dr. George Rutherford said.
Professor of epidemiology at UCSF, Dr. George Rutherford, disagrees with how the FDA put out this information saying the antigen tests are performing well with detecting true negative cases.
“FDA’s giving you a different statistic which you know you’d like to think would perform better but given the relatively low rate of disease, it’s performing quite well,” Dr. Rutherford said.
However, Dr. Rutherford reiterates what we already know about the at-home tests, that timing is crucial and the PCR molecular tests are the most accurate option.
“There are some timing issues with it, if you do it too early it’s not going to pick it up. That’s not a fault of the test. It’s just the timing of it,” Dr. Rutherford said.
If using the at-home rapid tests, Dr. Rutherford says you can count on accurate results as long as you test twice, a couple of days apart.