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Oxygen deficiencies may be behind Covid-19’s toll on people of color

“It’s really shocking that the FDA only had until 2021 to issue a warning,” said Uche Blackstock, an emergency medicine physician and executive director of Advancing Health Equity. “And even last year with that alert, they didn’t even mention racial bias, race or racism in it.”

The problem raises broader concerns about bias as the technology becomes more embedded in health care, and the ability of government to challenge it through regulation and oversight. Experts warn that disparities in outcomes between racial groups could worsen if the technology doesn’t work for all patients.

Researchers identified problems with pulse oximeters years ago, with small studies suggesting inaccurate readings in people of color. 1990, 2005 and 2007.

The Covid-19 pandemic has brought renewed attention to the devices, which usually come in the form of sensors at the patient’s fingertips.

Michael Sjoding, a pulmonologist and critical care physician at the University of Michigan, conducted The study was published in December 2020 in the New England Journal of Medicine, which showed that black patients were about three times more likely than white patients to have undetected low blood oxygen levels between January and July 2020, as well as in 2014 and 2015. More than one in 10 black patients with an oxygen saturation reading between 92 and 96 percent on a pulse oximeter actually had a level below 88 percent when measured by a blood test.

Normal levels range from 95 to 100 percent, and levels below 88 percent are considered dangerous.

Experts also say the problem points to the need to update the guidelines to compensate for the problem, as well as to diversify clinical trials.

The effect on care is real, Sjoding said. “This level of difference, if recognized and identified, would change the way we care for the patient,” he explained. “You would give the patient more oxygen or potentially give the patient a different treatment.”

known and unknown

Experts say the imperfections are the result of how light is absorbed by different skin tones. Pulse oximeters work by shining light on a person’s skin and monitoring how much bounces back, said Achuta Kadambi, an engineering professor at the University of California, Los Angeles.

Darker skin reflects less signal than lighter skin, which can distort pulse oximeter readings, he said. Kadambi, who has darker skin, faced similar problems with automatic soap dispensers, which also rely on light to activate.

“The laws of physics are against dark objects involving the skin,” Kadambi said, adding that algorithms are one way to fix the problem.

But the study results so far have limitations because they were not all differentiated by oximeter type, said Amira Mohamed, a professor at the Albert Einstein College of Medicine. He also noted that generalizing by race can also be difficult.

“There are different types of black people,” Muhammad said. “I’m black myself, and that doesn’t mean it’s going to work on me like it’s going to work on, say, my husband, who is a dark-skinned black man.”

Mohamed also says that the current research was mostly done on people with white skin, and that future studies should focus on people who are more likely to be affected.

Potential solutions

Current FDA guidance It is recommended that manufacturers’ studies include at least 10 people and “at least 2 darkly pigmented subjects” or 15 percent of the total group.

Some experts argue that the FDA needs this pool to be larger.

“Basically, you don’t have enough information about the accuracy of a device if you only test it on two people,” Sjoding said.

More specific guidance from the FDA on oximeters is warranted, said Ashraf Fawzi, a professor of medicine at Johns Hopkins University and lead author of the book. The May study was published in JAMA Internal Medicine found that providers overestimated the severity of illness and delayed treatment for black and Hispanic Covid-19 patients.

Faster action by the agency would be helpful, Fauzi added. The FDA should consider adding a warning label to the devices, said Kimani Toussaint, an engineering professor at Brown University who is working on a potential fix.

Some experts, like Blackstock, argue that oximeters should be taken off the market. Others, like Muhammad, say much more research is needed before conclusions can be drawn.

“If we’re worried about someone’s breathing or someone’s oxygen level, it’s not safe to rely entirely on a pulse oximeter, and we always need to confirm that,” Muhammad said.

And fixing the problem in the devices themselves can be difficult.

An FDA spokeswoman said it is trying to expand the available data on the problem

Funding for a prospective clinical trial to inform any change in recommendation. He hopes the study can sort out the “sometimes conflicting data that includes non-public information” that manufacturers have provided.

Meanwhile, researchers at Brown University are working on using a single wavelength of light to bypass the skin. Research in healthy patients is in its early stages and has seen results similar to commercial devices. Inaccuracies are more common in sicker patients, said researcher Rutendo Jakachira, who works with Toussaint.

Scientists are also looking at using sound as a potential replacement for light as a new way to read blood oxygen levels.

A variety of clinical trials

As technology plays an ever-increasing role in health care, experts say clinical trials, in which people of color have long been underrepresented, need to be overhauled.

Legislators are busy. The House passed last month FDA medical product user fee legislation that included language aimed at enhancing diversity in clinical trials.

Adrian Aguilera, head of the Digital Health Equity and Access Lab at the University of California, Berkeley, said that in the absence of diverse participants, the trial results do not necessarily reflect what will happen in the real world.

Trials are traditionally conducted in person, requiring participants to come to the site, which can create barriers for people with low incomes or people with inflexible jobs. lawyers You want to use telehealth Attracting a wider range of participants.

Companies should avoid “helicopter” research and instead spend time building relationships with community organizations and people on the ground, Aguilera said.

“An example of this situation with the pulse oximeter is that if you don’t think about bias and racism in the first place and you’re not intentional about it, it’s going to be embedded in the technology,” Blackstock said.

Oxygen deficiencies may be behind Covid-19’s toll on people of color

Source link Oxygen deficiencies may be behind Covid-19’s toll on people of color

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