FDA recommends more robust testing of pulse oximeters to avoid bias in people with dark skin tone

The Food and Drug Administration on Monday bolstered its recommendations for pulse oximeter testing following public uproar over how inaccurate readings led to different medical care for patients of color during the pandemic.

Minnesota medtech companies have said they were working on boosting clinical trial diversity and oximeter accuracy before the long-awaited release of the FDA’s draft document. The new guidelines increase the minimum size of the testing pool of participants for oximeters receiving the agency’s clearance from 10 to 150, and say at least 25% of trial participants should have dark skin tone instead of just 15%.

Studies have found pulse oximeters miss three times as many cases of low-oxygen levels in Black patients as in white patients. That disparity caused an outcry during the early days of the COVID pandemic because pulse oximetry data helped determine who received care, including hospitalization.

The new guidance recommends companies test the devices in patients with wider ranges of skin tones, including from three subgroups of the 10 levels in the subjective Monk Skin Tone scale. The guidance affects several types of the device, including those for the ear and more common clamplike fingertip pulse oximeters shining bright light through the blood, measuring how it reflects and scatters light while subtracting signals not involving the pulse.

The guidance is not final and is open to comments and suggestions for 60 days. It also not does address oximeters marketed as “health and wellness” devices, which typically are cheaper than FDA-cleared pulse oximeters and are sold over-the-counter. Some have criticized the lack of regulation for accuracy surrounding these devices.

CEO John Hastings of Plymouth’s Nonin Medical, which launched the fingertip pulse oximeter in 1995, said the company is “encouraged to see the proposed guidance from the FDA and share the agency’s commitment to improving the performance of pulse oximeters across all skin types.”

He said health and wellness pulse oximeters need to be regulated, too.

“In addition to the updated guidance on FDA-cleared pulse oximeters, we believe there is a need for performance regulation of Health & Wellness-grade oximeters which constitute the vast majority of the consumer market and have shown to demonstrate concerning accuracy for dark-skinned patients,” Hastings said via email.

Medtronic, which is run from offices in Fridley and sells oximeters largely used in medical settings, said the company looks forward to participating in the open-comment period and contributing to final guidance on pulse oximetry.

“We are pleased to see progress with the issuing of the new draft guidance for pulse oximetry. We are also proud to say that this important work is already underway at Medtronic, including a multifaceted approach to achieving equitable care in pulse oximetry for all patients,” an email from the company said.

One year into the pandemic, the FDA issued a safety communication to note pulse oximeters can return inaccurate results because of elements including skin pigmentation.

A 2023 study in the American Journal of Epidemiology found pulse oximetry systemically overestimated oxygen levels in Black individuals compared with white individuals. That meant Black patients had a lower chance of getting dexamethasone, supplemental oxygen or a hospital admission.

In additional to recommending companies assess trial participants using the Monk scale, the agency said manufacturers should also assess participants using an objective, math-based process called colorimetry to find a second metric of skin color.

Hastings said Nonin has “long prioritized accuracy and equity, helping to ensure our devices deliver accurate results across diverse patients” as a leader in pulse oximetry.

Previously, Medtronic hired third-party firms to carry out pulse oximeter testing, an executive recently told the Minnesota Star Tribune. Medtronic said it has been conducting a clinical study using the Monk Scale in its new Clinical Physiology Lab located in Denver.

“This clinical research is vital to bridge gaps in health care, improve the science behind medical technology, and advance Medtronic’s health-equity initiatives,” a form for prospective research participants of the lab says.

Health care publication STAT had previously reported FDA officials had been saying for months that the agency would publish its draft recommendations by Sept. 30.

Rachel Brummert, a patient advocate who served as the consumer representative to an FDA panel last February discussing the proposed guidance changes, said in an email to the Star Tribune last week the agency “must act more expeditiously to avoid further patient harm.”

An FDA spokesperson said in a statement last week the agency had been “working diligently” to update its 2013 final guidance and was committed to issuing new draft recommendations “as expeditiously as possible.”