Study: Blood oxygen detection device gives Black people inaccurate readings more often

A medical device that measures oxygen blood levels is more likely to give misleading or inaccurate results to Black patients, according to research published Thursday in the New England Journal of Medicine.

Researchers analyzed data from thousands of adult patients who received supplemental oxygen at the University of Michigan Hospital in Ann Arbor, comparing the data to that of 37,000 patients at about 200 other hospitals’ intensive care units.

The finger-worn pulse oximeter, they found, was more likely to return inaccurate results for Black users based on comparisons of the data to a test that takes arterial blood samples.

“In the University of Michigan cohort, among the patients who had an oxygen saturation of 92 to 96 percent on pulse oximetry, an arterial oxygen saturation of less than 88 percent was found in 88 of 749 arterial blood gas measurements in Black patients and in 99 of 2,778 measurements in white patients,” the study stated.

The devices are likely in wider use in recent months due to the coronavirus pandemic, the study notes. The research suggests Black Americans, who have been disproportionately affected by the pandemic, may also be at heightened risk of low blood oxygen in health care settings that rely on the devices to triage patients.

The devices shine a red light through the user’s fingertip, and for those with darker skin, the device may give misleading readings, Michael Sjoding, a pulmonologist who was the study’s lead author, told NPR.

The errors, he said, occur about three times as often in Black patients.

The inaccurate readings are “not happening a lot, but if you think of how often these measurements are taken, if it’s wrong 12 percent of the time, I worry that could be really impactful,” he said.