Years of research have highlighted a troubling issue: pulse oximeters, the small, fingertip devices that estimate blood oxygen levels, often produce less accurate readings for individuals with darker skin tones. In response, the US Food and Drug Administration (FDA) is stepping forward with new draft guidance aimed at improving the reliability and fairness of these medical devices.
Pulse oximeters gained widespread use during the COVID-19 pandemic, both over-the-counter and in clinical settings. However, studies have repeatedly shown that for people with darker skin, these devices can overestimate blood oxygen levels. This discrepancy can lead to delayed or inadequate treatment, particularly for critical illnesses.
On Monday, the FDA announced recommendations for manufacturers to address these disparities. Among the proposals is a requirement to include a diverse group of at least 150 participants in clinical testing, ensuring that at least 25% represent different skin tone groups as defined by the Monk Skin Tone scale. The FDA also suggests prominently warning users in device instructions about the potential for varying accuracy based on skin pigmentation.
Dr. Michelle Tarver, from the FDA’s Center for Devices and Radiological Health, emphasized the importance of these guidelines: “Our draft recommendations are grounded in the best available science to address concerns about device performance disparities.”
The proposal invites public comment over the next 60 days before being finalized. Importantly, it covers medical-grade pulse oximeters but not over-the-counter models often sold for wellness purposes.
Pulse oximeters work by shining light through the skin to measure blood color—bright red for oxygen-rich blood and darker hues for oxygen-deficient blood. However, darker skin pigmentation can interfere with light absorption, leading to less reliable readings. This issue has been known since the 1980s, with recent studies adding urgency to the matter.
For instance, one study of over 3,000 ICU patients found that Black, Hispanic, and Asian individuals received less oxygen therapy compared to White patients due to inaccurate pulse oximeter readings. Another analysis during the COVID-19 pandemic revealed that pulse oximeters overestimated oxygen levels in patients of color by up to 1.7%, potentially delaying life-saving treatments.
While the FDA’s guidance is voluntary, experts like Dr. Theodore Iwashyna from Johns Hopkins University argue for stronger enforcement to ensure compliance. “Without enforcement, it’s unclear why these recommendations would lead to better devices or care,” he noted.
The agency has also proposed creating a public webpage listing pulse oximeters that meet its new guidelines. While this is a step forward, concerns remain about whether the guidance will apply to widely available over-the-counter models.
Public health advocates, such as Harvard’s Carmel Shachar, see potential in the FDA’s approach. By incentivizing compliance through labeling and public recognition, the FDA hopes to encourage manufacturers to produce more equitable devices. Still, experts caution that safety standards must reflect actual patient needs rather than what existing devices can achieve.
As the FDA seeks public input, the hope is that these measures will lead to meaningful changes in the design and use of pulse oximeters, ensuring more equitable healthcare for all.