25 attorneys general implore FDA to improve pulse oximetry tech for darker skin

Attorneys general representing half of the U.S. and Washington, D.C., are calling on the FDA to step up its ongoing efforts to eliminate racial biases from pulse oximetry readers.

Last November, the regulator convened a meeting of its medical devices advisory committee to delve into the technological issues that can cause pulse oximeters to deliver inaccurate results for people with darker skin tones, and come up with new recommendations surrounding the regulation and usage of the devices for medtech makers, doctors and patients.

Exactly one year later, on Nov. 1 of this year, a cadre of 25 attorneys general signed a letter penned by California’s Rob Bonta asking the FDA to put the findings discussed at the meeting into action.

A spate of studies published in recent years describe how many widely used, FDA-cleared pulse oximeters have a habit of producing inaccurate results for many nonwhite patients.

Because fingertip-worn pulse oximeters work by sending light beams through the skin to measure the amount of oxygen in the blood, according to the researchers, any devices not developed and tested on a variety of skin tones will inevitably have trouble calculating the amount of light that passes through darker skin and can therefore potentially display oxygen saturation numbers that are higher than a patient’s actual O2.

Those inaccuracies mean that many BIPOC patients—who already face a variety of other race-based inequities in accessing healthcare—may experience life-threatening delays in receiving necessary care. One 2020 study, for example, found that Black patients were almost three times more likely than white patients to experience “hidden hypoxemia” that wasn’t spotted by a pulse oximeter.

These inequities were further exacerbated by the COVID-19 pandemic since pulse oximetry has been a crucial tool in monitoring the health of patients hospitalized with the coronavirus. Another study in 2022 concluded that Black and Hispanic patients experienced statistically significant delays in receiving needed COVID therapies, including supplemental oxygen.

In their letter (PDF), the attorneys general call on the FDA to “act with urgency to address the inaccuracy of pulse oximetry when used on people with darker-toned skin.”

The letter cites new data doubling down on the findings that faulty pulse oximeters contributed to delays in COVID care for nonwhite patients, while also highlighting growing concerns about the use of the technology elsewhere: Pulse oximetry is not only a crucial tool in maternal and newborn care, but it’s also being added into new predictive diagnostics, so failing to rectify the technology’s current issues “could end up reproducing health disparities based on race.”

The state lawyers offered six proposals for the FDA to enact immediately. They include a requirement for all pulse ox makers to include labels on their products about the potential race-based inaccuracies and a suggestion that the FDA send a letter to all healthcare providers describing the technology’s risks and updated usage guidelines. They also asked the agency to speed up its review and public release of the proposed recommendations from last year’s advisory committee meeting and to finalize new rules that would require clinical trials of medical devices—including but not limited to pulse oximeters—to be “demographically representative.”

In addition to those “urgent actions,” the signers also asked the FDA to support research and development efforts regarding how both new and existing pulse oximetry devices can be made more racially equitable.

“In this moment, our country faces multiple epidemiological and other public health, safety, and national security threats,” they concluded in the letter. “The accuracy of diagnostic devices to ensure timely and potentially lifesaving access to healthcare should not be one of them.”