How Did Race Get Into Lung Testing?

You'll start off by breathing normally. After a few normal breaths, I'll tell you to take a really full breath in.

It's a Friday afternoon at Moffitt Long Hospital in San Francisco, and a first-year medical student is learning how to perform a basic breathing test. He sits in an enclosed glass cubicle about the size of a phone booth, and puts his mouth around a plastic tube, and breathes in and out.

On this one, full breath in. In and in bloop.

Thank you.

This one's so much better already. A lot faster.

The spirometer helps doctors diagnose and treat most lung diseases, including asthma, COPD, and cystic fibrosis. It also helps determine who may be eligible for a lung transplant.

AA. Really good job.

Moffitt Long Hospital in San Francisco, where this breathing test was performed, is also where doctor Aaron Baugh is on staff.

I am an assistant professor of medicine at the University of California, San Francisco, and my specialty is pulmonary and critical care medicine.

Aaron Baugh first learned how to use a spirometer about 15 years ago when he was in medical school. That's also where he was taught that black people have smaller lungs than white people. His professors explained that it came down to evolution and body proportions.

They would say, well, people that live near the equator tend to have generally longer limbs and a shorter trunk. So that would mean then a smaller chest cavity and smaller lungs to go inside that smaller chest.

Aaron was taught that since black people have smaller lungs, they naturally breathe in less air.

So when you're looking at lung function, you have to take this into account and you have to correct for it.

Here's how the correction works. The spirometer has a medical equation built into it. When a patient breathes into the machine, their lung capacity is compared to what is considered normal for their age, gender, and race. For black patients, that normal range was set 10 to 15% lower than for white patients. Doctors believe that a race correction made the test more accurate.

It's not something that is problematic. It's not something that was caused by anything about their life or their treatment or anything. It's just the state of nature.

At the time, Aaron didn't question the idea of tailoring treatment for different races. As a black man himself, he was concerned by the health disparities between African Americans and other racial groups. So if biology was one of the reasons why black people have more lung disease, Aaron agreed with using a race correctly.

black patients have fourth health outcomes. And so I was really happy to hear like, wow, they've really done some research and they've thought this out. They are recognizing these important differences and then letting the differences guide the way we treat people and that is gonna be a positive thing.

That's what Aaron thought until one day in 2019. Aaron's boss reached out to him with something urgent to discuss. He told Aaron about an article in the New York Times. It was part of the 1619 Project, an initiative to examine the legacy of slavery. And in the article, the author called out the spirometer, saying it was a racist test.

They were saying that spirometry or the way that we measure lung function is inherently biased, is fundamentally wrong.

The article said that in the nineteenth century, doctors in the US used the spirometer to validate their theory that African American lungs were inferior. And that the race correction in modern lung tests was a legacy of this racist idea. But Aaron and his boss disagreed. They felt that the author of the article, who was not a doctor, didn't understand the biology.

We thought, oh, well this article lacks a lot of context because yes, no one's defending these people from the eighteen hundreds, but things have advanced a lot and we have a lot of science that backs up what we do now. So if only they understood.

They discussed how to respond. Aaron's boss asked him to investigate.

The thought was, well, we're all scientists, so what we should do is put our money where our mouth is. We can do an updated study and we can re-look at this question. And that way we're gonna demonstrate why this layman in the New York Times is so mistaken about their understanding of lung function, and we're really gonna show that recognizing that All these racial differences are all natural is the best thing for patient care.

Aaron and his colleagues set up a study to analyze the accuracy of the spirometer test. Was using race correction more accurate as they believed? Or would removing race from the equation lead to better diagnosis? They studied 2,500 patients from 10 hospitals around the country and measured their lung function in multiple ways.

We looked at things like how far you can walk in six minutes, we looked at their self reported symptoms, and we looked at things like the average thickness of their airway wall,

This was in the spring of 2020. COVID was wreaking havoc in the U.S., especially in black and brown communities. As a critical care pulmonologist, Aaron Ball was spending long shifts in the ICU and finding time for his study in between. Early one morning after an overnight shift at the hospital, Aaron returned home to his apartment and changed into his pajamas. Pacing around his kitchen, he decided to finally review the study data.

The computer's loading. The statistical program is going through. Bam. And it said, the difference is the race neutral is way better than the race base. And I was like, wait a minute, what? And I pressed the wrong button, what happened?

Aaron ran the numbers again. Same result. But he still didn't believe it.

I'm tired. I'm gonna close this computer. I'm gonna take a nap. I'm gonna get up and do it. So then the third time I wake up, open it up, double check everything, and then hit run. And again, big difference in favor of the race neutral. And it's like, oh my goodness, like I I think we have something here.

The study showed the black patients were much sicker than their spirometry tests reported. Race correction was actually masking the severity of their lung disease.

It was just kind of a big O moment. That was not what we expected to find now, right? It's a scary moment and it's an exciting moment. It's scary because everything you've been doing is wrong.

This is the race equation, a special series from the New England Journal of Medicine. I'm Rachel Gottbaum. In this series, we're investigating why race is programmed into medical equations that help doctors diagnose and treat disease. How did the idea that black bodies are biologically different from white bodies? Гетто практиці, а вот секунси.

In our first episode, we told the story of how medical students and the Black Lives Matter movement finally forced hospitals to stop using race in kidney function tests because it was preventing black patients from getting life-saving treatment. But we also learned that there are many more of these race-specific diagnostic tools that are still being used today, like the spirometer. Here's pulmonologist Aaron Baugh.

This is not a small test. It is used in diagnosis of lung disease and It is used for job hiring, disability assignments. It is used in consideration of different specialized medical treatments and therapies. So it can touch people in a lot of important ways if you're doing this wrong.

It took Dr. Aaron Baugh time to digest the results of his study. He was horrified that the test he and other doctors had relied on for years was actually hiding lung disease in black patients. Now he began to understand why those patients were often sicker and ended up in the hospital more than his white patients, even though their spirometry results appeared normal.

When I thought about my actual practice in the patients, I was seeing the outcomes were so much worse. coming to the hospital with a respiratory illness or having pneumonia or when I go into the room and talk to the patient, I may be getting a very different picture than what those numbers were telling me.

He needed to understand how a test that distorted the results for Black patients could have become a standard diagnostic tool in American medicine.

That pointed me to the work of a brown historian named Lundy Braun.

I'm

Lundy Brown. I have been for about 40 years a professor of pathology and laboratory medicine and Africana studies at Brown University.

I interviewed Lundy Braun before her death in 2024. She told me that one morning in 1999, she was reading the newspaper when a story caught her eye.

I was sitting down at the kitchen table and I saw this article in the paper about the lungs of black people being smaller than the lungs of white people.

The article was about a lawsuit. Shipyard and steel workers in Baltimore were suing an insulation manufacturer for exposure to asbestos. The workers claimed they'd become sick breathing in the toxic particles. The company wanted to block black workers from the lawsuit, arguing that since they biologically had lower lung function, they weren't actually sick. They said this idea was backed by science and the American Thoracic Society, but none of this made sense to Lundy Braun.

I was taken aback, if not totally shocked. by this notion and I wondered where it came from.

To Lundy, the argument by the company seemed racist. The white workers were entitled to compensation for damage to their lungs, but not the black workers? How could that be?

It really m was infuriating. Then I thought I'm just gonna look at this as dispassionately as possible. Because it can't be true.

Ultimately, a judge dismissed the company's claim, and the black workers were allowed to sue. But Lundy wanted to understand why the country's leading pulmonologists were backing a theory that contended black lungs were naturally smaller than white lungs.

So I approached a good friend of mine who was an occupational physician. And asked him about it. And he said, Yes. The consensus in medicine was that the lungs of black people differed from the lungs of white people, that they were smaller. And that was built into the medical evidence. That's how people were trained.

At the time, Lundie Braun was part of a race, medicine, and social justice group at Harvard, and she brought in the newspaper article about the asbestos lawsuit. She wanted to know, had anyone else heard that black lungs were smaller than white lungs? Evelyn Hammonds, a professor of the history of science and African American studies, was leading the group. She was as shocked as Lundy was by the claim, and she wanted to help her get to the bottom of it.

We just started with the basic question. Well, where did this very idea of differences in who first measured lung function and why?

They started to look into the evidence.

And then there's this striking section where he focuses on the body. And he says the bodies of these enslaved peoples are fundamentally different than white bodies. They're darker than us. And they have different features. I've observed that they don't seem to breathe the same way we do. And those differences are given by nature. They are innate and they will never change.

Jefferson wrote that African Americans sweat more than whites, which made them more tolerant of the heat. He said they didn't need as much sleep, and he speculated that their lungs were different and disabled.

Now Jefferson is an enormously complex man, but he laid that groundwork for exploring racial differences in notes on the state of Virginia. Even though he's not a physician, medical people take it up.

Doctors at the time paid attention to Jefferson's findings. But it wasn't until the invention of the spirometer in the 1840s that Jefferson's ideas about race and lung capacity were embraced by scientists. The spirometer was invented by a British surgeon. It was a large device that held an inverted glass container filled with water. A person would blow air into a tube, causing a bell inside the container to rise. Doctors would measure a person's lung volume by how high that bell rose.

Lung capacity was something that was supposed to be a measure of the vitality of a population. It comes about in in this new increasingly industrialized world. What are the bodies of these people who have to do this new labor?

In England, the spirometer was first used to examine the lungs of men of different classes. From the laborers building railroads to the gentry. But once the spirometer made its way across the Atlantic, it was picked up by an American plantation physician named Samuel Cartwright. And he used it for a very different purpose.

Cartwright picks it up because Cartwright is from the South. So the labor regime he's interested in is slavery, plantation slavery. And so that's why he turns to race.

Cartwright started by using the spirometer to test the lung capacity of his own slaves, and then he compared that to the lungs of his fellow white slave owners. He found a difference of 20%.

The measurements are all to support the belief now with solid in his mind. Their bodies are different than our bodies. Fundamentally different, and the natural condition of black people is slavery. Their bodies are fit for slavery.

Cartwright became an expert on the medical condition of slaves and was appointed a professor at what would later become Tulane School of Medicine. He published his findings in medical journals, writing that black people were more susceptible to respiratory illness because of their inferior lungs. Here's doctor Aaron Baugh again. He explains Cartwright's solution for treating low lung capacity enslaved.

The only way you can correct this is that if you physically beat them, that's actually a way of taking care of them because as they gasp in pain, they'll be taking in more air than they would at baseline.

According to Cartwright, black slaves had their own specific medical conditions, including an illness he called drape pneumonia, or the running away disease.

He said, Well, for a slave to run away is a sign of mental disease. Because their natural condition is slavery. They have to be unsettled somehow if they run away from slavery.

This is hard to hear, but these were the standard beliefs in the United States at the time. Cartwright's theories were picked up. They became a foundation for medical studies in the years ahead. Studies that were cited over and over again.

if you think about a snowball, the beginning of that thing was Cartwright and as it kept rolling downhill towards the present, We develop more and more momentum of looking into trying to find natural differences and then trying to assign meaning to natural differences. without thinking about, you know, what are the alternative explanations.

This was the era of race science. In 1865, the U.S. was emerging from the Civil War. Astronomer Benjamin Gould was hired to conduct a massive study of Union soldiers for a new Federal Commission. He was tasked with creating a catalog of the men, collecting their age, weight, lung capacity, and various body measures.

And I say, look, this is how you measure the width of the chest and check on how much they breathe in, how much they breathe out. It's not that uh precise. They actually know it's not precise, but as long as it confirms pretty much with what they already believe, they're fine with that.

The Commission published its findings in an influential report that spanned over 600 pages. It was filled with tables and measurements. And it showed that lung capacity in the black soldiers was six to twelve percent lower than the white soldiers. The report was considered definitive scientific proof that black lungs were smaller and inferior to white lungs. It was cited by doctors for generations and became a framework for the biological differences between the races.

Remember, you have a growing medical profession after the Civil War. You have an expanding medical education system. In those days you graduated from Harvard Medical School and this is what you learned. You consider that to be the best knowledge there is about bodies.

By the early 1900s, U.S. physicians increasingly attributed the higher rates of disease like tuberculosis and syphilis in the black population to innate differences in their lung capacity. But there are a few people who push back. They say maybe this isn't about biology, specifically W. E. B. Du Bois, an African-American Harvard-trained sociologist who co-founded the NAACP.

And he starts looking at the data that has been collected by these clinicians and physicians and just shows all these differences. He said, N no, th this is some really sloppy work. And if you'll do more careful work, which he did he doesn't find those same kinds of differences. He finds some high rates, but he attributes those higher rates of certain diseases to the social conditions and living conditions that black people had to live under.

Du Bois and other black scholars published their findings, but the medical establishment ignored them.

In the 20th century, more medical studies are done that reinforce the belief that black Americans naturally have lower lung function than white Americans. In the 1970s, a major study of asbestos workers in Louisiana showed a difference in lung function between black and white employees of 13.2%. Here's Lundy Braun.

They concluded that the difference that they observed in lung function was due to genes.

That study led hospitals nationwide to standardize race correct. And as new electronic spirometers were introduced, the normal lung function for black patients was set thirteen point two percent lower than for white patients. After 1999, additional racial groups, including Mexican Americans and Asians, received their own race correction in the spirometer.

And the machines made a huge difference in the sense that it offered a particular kind of authority and led people not to question so much. Because if you have a machine that measures it, then it must be true.

As recently as 2010, a paper published in the New England Journal of Medicine referenced Benjamin Gould's findings from Civil War soldiers that black Americans had lower lung function than whites.

I mean this is part of the problem. Studies are presented as scientific. And they're accepted as scientific if they're published in a scientific paper, in a scientific journal. And then those kind of very basic questions never get asked.

The bottom line is they never question the premise of the comparison in the first place. They never come back to the point, well, actually is there a real difference here? What kind of difference? And if there is a difference, what causes it? Is it an innate racial character or is it produced by social conditions, economic conditions, working conditions? They don't let those other questions enter.

It would take more than 15 years for Lundy Braun to publish her work on the history of the spirometer. Her book, called Breathing Race into the Machine, came out in twenty fourteen. At first, her research was largely ignored, and then, she says, she faced hostility.

I was sometimes told to like calm down. Or I was other times told that how could I question all these scientists? I wasn't a pulmonologist, but by and large, people just said I was wrong and that I didn't understand the science.

But in 2020, everything changed. First, the COVID-19 pandemic, when the nation saw a greater number of black and brown patients die. And then the brutal killing of George Floyd by police. Here's Dr. Aaron Ball.

On national television, on police body cameras, the whole nation watched a black man be murdered and suffocated to death while he screamed some twenty times, I can't breathe.

The protests that followed George Floyd's death motivated many people in medicine to push for change. In 2021, Aaron Baugh and his colleagues published their study showing that race correction in spirometry was masking the severity of lung disease in black patients, making them appear healthier than they actually were.

Wow, we can no longer ignore this. We cannot defend our older practice of just Saying, trust us, you don't need to look into this, just keep using race based. We need to hit a pause and consider using race neutral approaches.

Aaron Ball joined up with other doctors to try to get the medical establishment to remove race from pulmonary function testing.

Around the same time, Lundy Braun was starting to get recognition for her work on the history of the spirometer.

The intent of my research was that this is a racist practice and that it should be ended. It's not about race getting into this fabric of medicine, but

Okay.

In 2021, Lundy Braun and Aaron Ball were both invited to join the country's leading experts on lung health to review pulmonary function testing. The American Thoracic Society debated for two years whether to remove race from the test's algorithm. In 2023, ATS finally came out with a new recommendation. Doctors and hospitals should use race neutral tests. They should stop adjusting the spirometry score for black patients or any other group.

It's now 2026, and despite the work of Lundy Braun, Aaron Baugh, and many others, the majority of hospitals and doctors in the U.S. still use race-corrected spirometers. And Aaron Baugh is frustrated. He says using a race neutral test is better for all patients.

I do want to emphasize what we found and what other people who this has found is we have found many benefits to white patients. It improves the correlation between understanding disease outcomes and lung function for all people.

So, why haven't more hospitals switched to race neutral lung testing if the science shows it's more accurate? For one, Aaron Ball says change is notoriously slow. Some medical professionals are reluctant to disavow what they've been practicing for years. And then there's the cost associated with replacing older spirometry machines.

So then you're talking about at my hospital I have to buy all new equipment that could be thousands or millions of dollars investment. Then I've got to be educated. What do these new values mean and how do I interpret them? So it's a big process to actually create a change in something so fundamental.

There's also the current political climate in Washington. The momentum to remove race as a bias in medical tools has stalled and in some cases come to a screeching halt. Many doctors we spoke to are concerned about the ripple effects. It took years to do the studies showing that race correction is harming patients. And yet now when they finally have the proof, they are being blocked from making the needed changes.

Reflecting back on his experience, Dr. Aaron Baugh says he wishes he'd questioned what he learned in medical school about biological differences a lot earlier. After he looked into the science, he saw that while some minor variations may exist, they don't explain the higher rates of lung disease among Black patients. He wants doctors to focus on the side. The actual reasons that their black patients are sicker, like living conditions, environmental factors, and access to medical care.

Is it just missing appointments? Is it about, you know, access to medications? Is it like, is it their diet? What is happening that explains? difference that's like the golden goose of we all wish we could find what is the factor or factors plural that contribute to this so we could address it in reverse.

Experience, proving that the established science was wrong and realizing that he and other doctors were actually causing harm has been humbling. But it's also reinforced a core tenet of being a physician. Listen to your patience.

It was kind of in front of us. And we had to do all this for me to say like, oh actually what if I just believed the patients when they said no, I really am like more short of breath. Your numbers aren't showing that, but that's what I'm feeling.

Next time on the race equation. And look at how the use of race in lung function tests is preventing thousands of black military veterans from getting the disability benefits they deserve.

we're doing this lung testing like this and it's not scientific and it's possibly hurting patients.

I have seen white veterans get more benefits and if they basing it upon color of a skin, that's not right because we are all veterans.

Anything that would result in fewer benefits, particularly fewer benefits to white patients, would be politically untenable.

I am zero percent confident that

They will make a change at this point. We are just banned from talking about anything that has race in it.

The race equation is a special series from the New England Journal of Medicine. This series is reported by me, Rachel Gop. Our senior producer is Catherine Fenelosa. Our editor is Sarah Kate Kramer. James Trout is our sound engineer. Andrea Lopez Cruzado is our fact checker. We had help from Dr. Winfred Williams, Christine Gwynne, Adam Strauss, and Leakadia Marchwinsky.