If a test is inaccurate, is it still worth using?

Nursing homes and other healthcare professionals around the country are asking themselves this question after the federal government late last week effectively forced Nevada to resume its antigen, or point-of-care (POC), testing in nursing homes. The state had halted the program due to the high incidence of false positive results, which emerged from two tests.

“While we welcome the opportunity to discuss your concerns with those two tests, the U.S. Department of Health and Human Services will take appropriate steps if you do not cease the improper unilateral prohibition,” Brett Giroir, M.D., of the Department of Health and Human Services said in a noticeably peeved letter dated Oct. 8 to Nevada officials.

The state shut down the antigen testing after finding that 39 positive antigen tests later yielded 23 negative results when confirming polymerase chain reaction (PCR) tests were undertaken. A bit troubling, isn’t it?

Yet Giroir argued in his letter that false positives occur with any test, including the gold-standard PCR variety, and that frequent POC results are still better than infrequent or long wait times associated with PCR tests. He also noted that low prevalence and incidence of COVID-19 in a community may result in higher rates of false positive tests.

To better hedge against inaccurate test results, facilities should use the POC tests as backup in certain cases, Giroir said. These cases include presumptive negative tests among symptomatic individuals, and positive results among asymptomatic individuals in facilities without outbreaks. Page 4 of Giroir’s letter includes a Centers for Disease Control and Prevention chart of possible eventualities.

Most would agree that the federal government deserves praise for last summer’s ambitious POC testing initiative, but the program, evidenced by the testing accuracy concerns, had some flaws. Still, the fact remains that there is limited weaponry against the novel coronavirus. If POC testing truly is better than nothing, facilities need to find a way to use it. If they can receive clear-cut guidance on how best to utilize it going forward, all the better.  

Liza Berger is Senior Editor of McKnight’s Long-Term Care News. Follow her @LizaBerger19.