SALT LAKE CITY — The Utah Department of Health announced Sunday that state-run COVID-19 testing sites will pause the use of rapid antigen tests starting Monday after an analysis of tests results pointed to potential flaws in the rapid tests.

Epidemiologists analyzed data after questioning the performance of the GenBody rapid tests offered at the testing sites. The health department found that more than half of nearly 18,000 Utahns tested with both a GenBody and PCR tests had different results on the same day.

While a negative rapid test is unreliable, the department found that positive rapid tests are "extremely reliable," according to a statement from the health department.

"While rapid antigen tests are known to be less likely to identify a positive individual, the difference identified in this analysis was higher than expected," officials stated.

Another analysis of people who received both a PCR test and a BinaxNow rapid antigen test found the BinaxNow tests perform better — less than a third of those with a negative rapid test also got a positive PCR test.

While the BinaxNow tests seem more reliable, the department said there is a nationwide shortage of the tests, adding that if the supplies of the test return to normal the state could bring back the use of rapid tests at their sites.

The department will offer at-home tests to anyone who gets a PCR test but needs rapid results, according to a press release.

Utah health officials also recommend that people who received a rapid antigen test between Feb. 2-6 at a state-operated testing site get re-tested with a PCR test or request an at-home test from one of the sites.