In January, the US Food and Drug Administration (FDA) unveiled draft guidance for pulse oximeter performance testing. The release of the guidance was welcome news among health care professionals, as it addresses known accuracy issues with these devices when used on patients with darker skin tones.

CHEST has been advocating for updated guidance for many years. Aaron Baugh, MD, who has been integral to those efforts, recently spoke with the CHEST Physician® publication about the draft guidance, including the many positive changes he believes are reason to be happy.
Dr. Baugh, Assistant Professor, School of Medicine, University of California, San Francisco, is a member of the CHEST Health Equity Task Force and previously presented a statement to the FDA on pulse oximeter accuracy and limitations. Continue reading for his insights on the new guidance.
CHEST Physician: This is pretty exciting. I know this is something CHEST has been working on for some time. So let’s talk about the draft guidance. Does it address everything you had hoped? What are your first thoughts?
Dr. Baugh: There are a lot of things to be happy about in the new draft guidance. If you look at the prior guidelines, they recommended very small sample sizes; they used only healthy volunteers and ideal conditions. And, of course, there was the infamous clause regarding diverse participants. The previous guidance recommended only three individuals or 15% of participants—whichever was larger—have dark or darkly pigmented skin, but they didn’t define that. With sample sizes so small that three participants could represent 15% or more of the study population, conclusions were statistically uninterpretable. Boosting the recommended total sample size to at least 150 participants means all subgroups will be adequately powered to give interpretable results.
There’s going to be a sea change.
First, the new guidelines recommend much larger sample sizes of at least 150 people, and they are stratified so a certain number of participants must be within different skin tone ranges. They define skin tone by both subjective—such as the Monk scale—and objective—such as calculation of individual typology angle—measures. And the minimum participation of patients with darker skin is now 20% to 25%—a huge increase.
They’ve also incorporated a lot of new information about how to test these devices in nonideal conditions—when there’s motion or in low perfusion situations. Is the device as accurate in the 70% to 80% range as it is in the 90% to 100% range?
There are so many things to be excited about; a lot of things CHEST has advocated for.
CHEST Physician: Are there things missing that you would still like to see?
Dr. Baugh: Something I would like to see elevated more is guidance surrounding conditions such as hemoglobinopathies and jaundice. We know such conditions can affect the accuracy of these measurements. While the guidance acknowledges this, it doesn’t offer recommendations for how we should be testing these devices in anyone other than healthy individuals. That could help us quantify how much certain conditions affect accuracy.
CHEST Physician: Comments on the draft guidance are being accepted until March 10. Do you foresee CHEST raising this—or other—concerns?
Dr. Baugh: CHEST has played a large role in getting us here, and I think we intend to continue being involved in this process and seeing how we can help the FDA produce the best possible recommendations. It’s much like published research. Our journals receive really great submissions, and the comments and peer review make them even stronger.
CHEST Physician: As you said, CHEST has played a large role in advocating for updating this guidance, and you’ve been involved throughout that process. For those unaware, tell us a little about CHEST’s advocacy efforts in this space.
Dr. Baugh: As you may know, CHEST was founded by a patient, which is unique among professional medical associations. If you look at the hierarchy of who holds influence in the health care system, patients are way down at the bottom. But our founder, Murray Kornfeld, believed he could bring something to the conversation. He believed that if you elevate the voices of the less powerful, it will make things better for everyone.
The bias in pulse oximetry caused by prior faulty guidelines is one of those issues that most adversely affects underserved communities. They are underrepresented in medicine. If you were mapping influence or power, this is a group you might put at the bottom of the ladder.
CHEST, however, was founded on this belief that we can elevate their voice and that it will make things better for everyone. And I think this new guidance demonstrates this. It’s a beautiful example of how giving voice to those with limited influence can improve things for everyone.
More specifically, we were privileged to be invited by the FDA to give testimony and feedback as they were developing this draft. We’re proud to have helped generate ideas for how to design studies that will create a sound basis of evidence. All of the direct advocacy, congressional hearings, and other efforts have all come together.
CHEST Physician: Is there anything else CHEST Physician readers should know?
Dr. Baugh: I think beyond making pulse oximetry devices more accurate, we also have to inspire public confidence—especially after trust has been broken, as it has been in this case. Our members see this when they’re interacting with their patients.
Part of what we addressed in our testimony was the need to separate the issue of race from the issue of skin tone. We need to assess them separately. I love that the guidance offers advisory statements that can be put on these products after they’re approved that will hopefully help to rebuild and sustain public trust.