'False sense of security.' Why some doctors won't order coronavirus antibody tests for patients

The Trump administration and other leaders around the world have proposed Covid-19 antibody tests, which can detect past infections, as a stopgap solution to reopening society until a vaccine is developed.

But even as labs are offering antibody tests, some patients have found themselves unable to obtain a physician's referral. We asked doctors to unpack that reluctance.

Craig Cooper's profession as a high-end jewelry broker requires him to travel beyond the Seattle area on a regular basis. He estimates that he flies 150,000 miles each year.

For his clients — who often write checks in the quintuple digits — photographs won't do, he said. They want to see his products in person.

Cooper had traveled to several major U.S. cities, including New York, around the time the nation's coronavirus outbreak began. Given his travels, he figured he'd be an ideal candidate for getting a Covid-19 antibody test — also called a serology test — when he heard about the University of Washington Virology Lab's capacity to run them.

"As I move out into the world, I want to do it with some sense of ethics," Cooper said. "I need to be able to tell clients, 'This is what I have done to ensure your safety.' If I don't address their needs, I'm going to lose their income. And that is to the tune of millions of dollars a year."

But his Kaiser Permanente provider denied his request for an antibody test referral, citing uncertainty about how to interpret the results. Some doctors are uneasy about how to explain Covid-19 antibody test results to patients — and so they've opted not to make those referrals.

For example, if someone at a nursing home that had an outbreak got a positive result, a doctor could tell that person with confidence that they probably did have the coronavirus. And if someone got a negative test result after living in an underground bunker since February, a doctor would be confident in telling them that they likely didn't have the virus.

But those situations are outliers. Most people have reduced their social activity, but still go grocery shopping, ride the bus, or live with someone who is an essential worker. Limited diagnostic testing supplies and contact tracing means health experts don't know the extent to which coronavirus lurks in Washington state.

There's also a concern among physicians that patients may test positive for coronavirus antibodies, and then forgo social distancing, wearing masks, and frequent hand-washing.

"We're all worried that people are going to take this as a license to not take every possible precaution, and to give people a false sense of security," said Dr. Elisabeth Poorman, a physician at the University of Washington's Kent-Des Moines clinic.

While conventional wisdom suggests the presence of Covid-19 antibodies would offer some protection against reinfection, scientists have pointed to knowledge gaps about how high those antibody levels must be to do so, or how long they'll remain in a person's blood. Moreover, the presence of antibodies doesn't necessarily mean that someone isn't still capable of infecting others.

Read: Covid-19 immunity permits for Washingtonians? 'We're not quite there'

Doctors might also have reservations about referring patients for antibody tests because of the potential professional ramifications, Poorman said.

"In America, a physician is fully responsible for all of the tests, medications, and orders that she places," she said.

"Unfortunately, because we have that system, that can tend to be very punishing to individual physicians. They have to be comfortable ordering the test and interpreting the results. So I think it's totally their prerogative if they want to do that."

Scientists at the University of Washington are using a Covid-19 antibody test manufactured by the Illinois-based Abbott Laboratories, Inc. The UW Virology Lab has endorsed the test as being more accurate than other tests on the market, citing a 100% sensitivity rate (the rate at which samples with antibodies are accurately identified) and a 99.6% specificity rate (the rate at which samples without antibodies are accurately identified).

The sensitivity and specificity rates of an antibody test are intrinsic to the test itself, Poorman said. But just because the test itself is highly accurate, doesn't mean interpreting the results is clear-cut.

Read: Yes, Covid-19 antibody tests are really available in Seattle. But patients have been told otherwise

Despite the murkiness surrounding antibody test results, Poorman sees value in conducting them.

"For public health reasons, it's really great that we're doing this antibody test because it helps us get a better sense of how many people have been infected," Poorman said. "What's the mortality rate? What's your likelihood to recover?"

However, she said, "for the individual patient, it may not be as helpful right now," considering social distancing strategies are believed to be successfully mitigating the spread of coronavirus in Washington.

Nevertheless, Poorman said she orders the Abbott antibody test for her patients who request it; she estimates she's made about a dozen referrals so far.

For his part, Craig Cooper, the jeweler, said he understands if the research surrounding Covid-19 antibodies isn't complete. Regardless of any antibody test results, he said he would still practice social distancing, wear a mask, and wash his hands frequently.

He said he's bothered by the inconsistency from provider to provider when it comes to willingness to order the test. Being self-employed, his Kaiser plan was the only health care coverage available to him through the state this year.

"In this pandemic, anyone who is doing anything at all that is from the health community, it should all be treated the same," Cooper said.

He also raised concerns about how fluctuating public health recommendations — such as the shift in guidance on wearing face masks since the start of the pandemic — might lead to missed opportunities to have taken certain precautions.

"We're all going to be putting ourselves back into the world sooner or later," Cooper said. "Since my trip that I took to New York two months ago, nothing is going to have changed, except everyone sitting on the airplane is going to be wearing a mask."

However, Dr. Poorman said it's important to understand that public health guidance is in flux because science is inherently dynamic.

"I don't make the same recommendations that my colleagues made 30 years ago, because I have the benefit of 30 years of data," she said. "Does that mean they didn't know what they were doing? No — they were responding appropriately to the information that they had."