non: [00:00:00] You're listening to the ATS Breathe Easy podcast brought to you by the American Thoracic Society.
Dr. Amy: Hello everyone. Uh, welcome to the ATS Breathe Easy podcast on pulmonary function testing and race, uh, race neutral pulmonary function testing. I'm your host, uh, Dr. Amy Attaway. We are so excited to be here, um, to discuss this topic with two, uh, experts in the field who both participated in the ATS workshop on race neutral PFTs.
And so I'm going to introduce them. Uh, first we have Dr. Nirav Bhaktra, uh, he is an associate professor at UCSF health where he joined us faculty in 2013. He's a clinician educator and researcher as well as director of education for their pulmonary function lab and was recently named a master [00:01:00] clinician at UCSF.
He was the first author on the ATS workshop on race neutral PFTs. We also have dr Meredith McCormick, who is a professor of medicine in the division of pulmonary critical care and environmental health services at Johns Hopkins. She's also medical director. of their pulmonary function testing lab and was the immediate past chair of the A.
T. S. Proficiency Standards and P. F. T. Testing. Welcome. Thank you both for being here. Thanks so much for inviting us. Um, I think there's, there's a lot to discuss, and we're really excited to talk about this today. And I think so previously, um, race based normal values were used to adjust spirometry, um, for certain medical tests, and there was felt to be different physiological values.
Maybe, uh, uh, Dr. Bakhtar, if you could kind of explain what pulmonary function testing is and some, what are some of the indications for testing and routine clinical care?
Dr. Nirav: [00:02:00] Yeah, a great place to start for us for all of us to get on the same page about what a pulmonary function test is. We use it as an umbrella term to describe a few different tests of the function of the respiratory system.
One of the core tests is something we call spirometry, and that's a measure of how much air can move in and out of somebody's lungs and how fast it can get in and out. Um, some of the other common tests are diffusing capacity tests and a lung volumes test. And so we call all of these things pulmonary function tests.
There are some other measures of the lung function, uh, of, uh, that we don't typically include in this category, but are also important like pulse oximetry, um, so that's oxygenation of the blood. Um, but in general, um, spirometry again, is that core test. These pulmonary function tests are quite useful in the evaluation of somebody presenting with general respiratory symptoms like shortness of breath or cough and are also [00:03:00] very useful for managing a number of specific lung diseases like COPD and interstitial lung diseases.
Dr. Meredith: In addition to our patients, we also use lung function tests sometimes to determine whether someone qualifies for disability. Um, and in some cases in occupational eligibility, like to see if somebody qualifies for being a firefighter is one example of an occupation that often requires long function testing or spirometry prior to being able to be qualified for that job.
Dr. Amy: And I think so when we have spirometry, um, we always have our, we have our reference population and then we have the testing is adjusted. Um, so previously it's been adjusted for age, height, sex and race. And that was kind of where the The ATS workshop began, which had a lot. I think reading the ATS workshop, they really go into the history of where this adjustment [00:04:00] for race began.
And I think it's, it's just a fascinating to read about it and how, how these changes kind of became ingrained and how we interpret our testing. I think, uh, Nirav, you're going to talk more about that, right?
Dr. Nirav: Yes. Um, so you mentioned Amy, that the tests, these tests are commonly adjusted for age, height, sex, and, um, or often adjusted for race as well.
And so when spirometry was initially measured on large groups of people starting in the mid 1800s, um, it was noticed that younger people, taller people, um, and an overall men compared to women had bigger, um, uh, lung volumes, uh, more amount of air that they can move in and out of their lungs. Um, some of these things, you know, make sense, especially like the taller you are.
Um, the those studies also looked at social class and people in different occupations and found differences between groups and long functions [00:05:00] very quickly thereafter, especially when spirometry came to the U. S. A few years later. Uh, there was an interest in measuring lung function and then separating out the data by race.
So black versus white. And that reflected, uh, the predominant way of thinking among the people who were making these measurements. Um, uh, people who are white, um, about differences between races and how that might Um, leaked, uh, associate with a common thinking about not only racial difference, but racial inferiority.
Um, and so that's how it became ingrained, um, in that, um, differences were observed and it fit people's ideas about racial difference. And, and so it got baked in and also reflected a general, uh, uh, placement of race in medical, um, algorithms.
Dr. Meredith: One of the things I think in the story of, of how we've. Evolved and [00:06:00] grown to think more broadly about race in the context of P.
F. T. S. Is that, um, one of the aspects I think is really inspiring is a catalyst for really the work that's been done was sparked in large part by medical students and early career early trainees who were going through their medical rotations and notice that race was included in algorithms across different specialties to question that practice and did so vocally.
Um, and so I think it's inspiring that, uh, new minds and new eyes really, um, questioned our current practice. Is and led to really a reevaluation of why we had considered race and algorithms and whether that was the best approach. And I think as Nirav mentioned, um, really, I think the practices over time were built on a construct that there are biologic differences by race.
And really, um, as this has [00:07:00] been reconsidered, a recognition that race is a social construct. Um, and that a lot of the differences that that have been observed at the population level are likely the consequence of environmental factors and social factors and maybe occupational exposures and a myriad of things that that don't, um, that are can't be represented just by, um, by a self reported, uh, categorization.
Um, it doesn't have a biologic construct behind it.
Dr. Amy: And so in thinking about how by adjusting for these, um, using race to adjust these equations, what was the, um, and kind of looking, looking back, and I know there's been lots of studies on this, what was the clinical significance of doing that? Are there some, uh, and I think you had some examples you were thinking of Meredith, right?
Dr. Meredith: Yeah. So I think, you know, one thing that's important to, um, recognize is that when we measure lung function, like [00:08:00] there, I was describing measuring the airflow in and out of the lung volume size, those measurements are made, um, and are reported in units like liters per second or liters of lung volume. Um, and those are actual measured values.
When we're talking about where race or height or age comes into play, that's sort of how we interpret the data that that is measured by the machines. Um, And so when we include race in an algorithm or in in the way we describe or create predicted values or expected values, um, when we are using a race specific approach, we have a black individual, for example, as their lung function testing done, we're comparing that person to to it.
Um, the reference population that self identified as black and a white person with a race specific approach would be compared to to the reference population of white people that had their lung function performed. And so what that [00:09:00] means operationally is for two people that have the same lung function when you're using a race specific approach.
A black person will have a higher percent predicted, so they'll have a value that that, um, is more shifted towards the normal range and a white person will have a lower percent predicted, um, and. Look more impaired for the same value measured value. And so that can have implications clinically.
Dr. Amy: And I think so.
There were some we had. We're thinking of some examples, and I think some you've seen clinically of what, like what this may do.
Dr. Nirav: Yes. And so, um, you know, piggybacking off of what Meredith was just saying about how the shifts can happen with the move, uh, or with, uh, if you look, if you compare people to just um, group that's, you know, overall higher or lower than another group.
Um, what can happen then is in the clinical space. Um, [00:10:00] if somebody needs a certain amount of lung function, uh, say, for example, lower than a certain amount in order to qualify for a particular treatment, um, then comparing them to people like them who have a lower lung function on average will make them look more normal.
Whereas comparing them to say another group that has a higher lung function, um, will make their values, the patient's value look lower and make you more, making them more likely to qualify for that treatment. Um, and then outside of the clinical, uh, realm in sort of these healthcare decisions that we make, uh, as Meredith noted earlier, the pulmonary function tests are also used in, um, other settings.
We can call them sort of administrative settings and these include. when evaluating somebody for whether they're it's safe. Um, uh, and whether they're fit to do a certain job like firefighting or commercial diving. Uh, and then, um, if they have a problem, um, uh, uh, an injury related to work [00:11:00] or they can't work for some other reason, um, uh, and they are impaired and are need to be considered for disability benefits, lung function can come into that decision making to decide does the person have lung function impaired to such a degree that they can't do that work anymore.
And it really matters in terms of who you're comparing that person to.
Dr. Amy: And so, and I know both of you were, were both very involved in this workshop and I know it took, you know, uh, years to develop this project, but ultimately the decision was to recommend the spirometry. So how is that, what did that mean specifically?
Dr. Nirav: Yeah, it was very specific, has a specific meaning in this context in that we recommended, um, based on, um, some evidence and a lot of the things that we've talked about here today. to not [00:12:00] use race when interpreting the pulmonary function test with reference values. And the way that's operationalized is to use, um, a reference equation, uh, that, I should say, use one reference equation, um, regardless of what race category that person may be assigned to or self identify with, rather than using a separate equation based on what race, um, somebody is assigned to.
And so we don't have to ask about somebody's race and don't have to select a race category than in the pulmonary function laboratory anymore. And we just use one reference equation. The specific reference equation that was recommended for spirometry was something called GLI global. Um, and often the year 2023 is sort of attached to that as well, just to distinguish that's the year that it, um, it came out in a publication.
And to distinguish it from another set of GLI equations that were published in 2012. So GLI is a global lung [00:13:00] function initiative, uh, uh, kind of a kind of a global group, um, whose goal was to collect high quality pulmonary function testing reference data from a large group of people around the world. Uh, and this specific equation, what it does, Is it takes an average of people who are already assigned by the investigators into different racial groups, and it takes the average of those and puts them together into one equation as a way of sort of representing everybody rather than having race specific equations.
Dr. Amy: And I think so. So for both of you, you both are kind of also a big part of your own pulmonary function testing lab. So not only did you get to help develop this and this change in clinical practice, you actually got to implement it in your own institutions. Um, so how has that, I would love to hear both of your thoughts on how that has been or how that, how [00:14:00] that went.
Dr. Nirav: How did your PFT lab make the change if they have made a change? And, um, you may be wondering if they haven't made a change. Well, what are the limitations? Why haven't they made one? And one of the things is that, um, it, in order to use a new reference equation, software most often needs to be updated, um, and.
Um, it could be the case that a lab is using a software that's so out of date that it can't be updated. Um, or even if it is with a modern pulmonary function testing, uh, reporting software, um, they may need to get an update from the manufacturer. Um, often this is going to cost money and take time and, um, support from the local, um, information technology, um, teams and sort of connecting it with the electronic health record.
Um, and so there's a lot of resources that are need to make the change. But I think is Meredith is going to mention here. There are [00:15:00] some alternatives.
Dr. Meredith: Yeah, I think what you've mentioned is really, there are some barriers that can be out there. If your software has G. L. I. As one of the options for the reference equations, which you end up choosing in the software as part of the primary function testing device, if you haven't gotten the update to get G.
L. I. Global, but you do have G. L. I. One thing that you can do is you use the category other for all the patients that come in So instead of selecting white or black, you select other for every patient. And then you're using the same approach for every individual. And it turns out that using GLI and applying other, which is a composite, um, category is very similar to GLI global.
So that's a way that if you have the ability to use any of the GLI reference equations for spirometry, you do, you should have the ability to designate every one other. We use that actually as our [00:16:00] first step in implementation, and it still took some steps because we have to explain to our technicians to do that.
Some people sort of forgot. And so there was a little bit of time. We have to just streamline our process and do education and reeducation to make sure that everything was done in the same way. And ultimately, we were able to just automate that until July. Global was Is available.
Dr. Amy: And I think there's also some educational materials right that we were taught that are available.
Yes. So one of us. Yeah,
Dr. Meredith: you're I was describing one of the steps of implementing it in the lab. But then there's also sort of the implementation piece of now in your clinical practice. And so, um, if you have a PFT report or and you're not sure what was used, your reference equation should be listed as part of the report in every patient.
And in our report, we have a visual diagram that shows it has green and yellow and orange and red, a visual display of, of where a [00:17:00] patient's lung function is for, for example, for their FEV1, and it also has cut points. And so for some of my patients, they might have changed from mild to moderate or moderate to mild between visits, even though their lung function was pretty much the same.
And so I was able to have been able to show them that visually and also just describe that when you're on either side of a cut point, like a boundary, if your lung function is right near that boundary between mild and moderate, that just going a little bit in either direction can shift that designation or category.
But, but really it doesn't represent a change in their actual lung function. So that's been helpful.
Dr. Amy: It makes us all think about like how we define disease, right? We have these cut points, right? Is there, is there something you've noticed in your clinical practice?
Dr. Nirav: I think overall, it's going to take more study, um, to really understand how people treat, um, uh, borderline values, um, [00:18:00] whether, uh, you know, people will look at, say, um, the visual color bars or placement of things and say, Maybe as a clinician, I'm going to take into account more information, other aspects of the case, for example, the symptoms that the patient's having their trajectory, the imaging characteristics and, um, decide, uh, you know, whether to make sort of further mental shifts, um, or whether people just go with, um, whether they're above or below.
Um, and so there's going to be a lot of investigation, I think, um, out on the heels of this change, um, um, in laboratories to understand. Um, how people's practice changes given, um, the shifts, um, there are, uh, examples of clinical examples, um, where moving above and below the cut point is gonna have an impact.
And so I can just give two examples. You know, one example is, uh, for lung [00:19:00] transplant referral where, um, and so to be specific here, even though If somebody has been evaluated for lung transplantation and is deemed a candidate and, uh, is put on a waiting list that their position on the waiting list is not currently impacted by pulmonary function testing.
Um, however, the, uh, uh, international guidelines. for clinicians on when to consider referral to a lung transplantation center or specialist, um, do include, um, suggested lung function cutoffs, um, in addition to a lot of other clinical information. So, for example, with COPD, even though symptoms, uh, frequency of exacerbations, uh, and a few other things that you go into it.
The guidelines also list a spirometry cut off. So one of the measures from spirometry is the forced expiratory volume in the first second of exhalation called the F. U. V. One. And the guideline says if you're [00:20:00] less than 20 to 25 percent predicted, that's another reason to consider referral. And so If there are cases where people are not meeting the other criteria, but, um, would have by lung function and the changes made from race specific to race neutral, um, for example, for a black that could now their lung function and they could get referred earlier.
Conversely, for a white person, they may go above the threshold and may, um, get referred a little bit later. That's one, you know, example, um, and, uh, throw out another clinical example there that moves in the other direction, um, is that, well, actually, it's the same direction, I should say, um, is, uh, treatment, uh, of, um, uh, amyotrophic lateral sclerosis, ALS, with respiratory muscle weakness with [00:21:00] a noninvasive ventilator.
Lung function needs to be below a certain amount, uh, in order to, um, uh, get that kind of treatment. And it's going to be the same changes then that happened with a lung transplant referral.
Dr. Meredith: It's pretty complicated, so it can can be hard to understand or really explain why, why we're talking about race and pulmonary function at all.
Uh, and we have worked with the American Thoracic Society to create patient facing materials, and those are available on the website. Just to provide a little bit of foundation, and I found those helpful to really start that conversation or if a patient's asking about why their lung function might look a little bit different, those resources are available.
Dr. Amy: Yeah, I think, I mean, ultimately, we've, we've kind of looked back and, you know, trying to think about how we've been doing things like this is, this is the more accurate way clinically. So I think that's really exciting. But I know there's, there's lots to think about in the future, right? Like what's, [00:22:00] what, where do we go from here?
And, um, I think there's a couple of things we're still thinking about of how to, how to make the process even better or what things we need to study more.
Dr. Meredith: I think we're seeing more and more publications about the implications. There was a, um, publication in the New England Journal trying to quantify some of these, uh, different implications that we might see.
And like we've talked about today in the context of disability and in occupational eligibility, as well as in referral for treatments. And you can see that at a population scale. You know, can affect millions of people and and also have affect millions of dollars of disability benefits. So really putting that in the population level context, I think at the individual level will will, um, I think will be work looking at new ways.
But we've talked a lot about the population that described normal or abnormal or severe [00:23:00] lung function based on measurements taken in the population level. But I think as we're thinking about ways to, to, uh, create approaches to defining impairment or normal versus abnormal, we'll see more, um, ways mathematically we might be able to use the absolute values or other characteristics of, of patients that may become more, more precise or more refined over time.
Dr. Amy: And I think, uh, there was also a need, I think, for a reference, like future studies and a new reference population, or is that,
Dr. Nirav: yeah, uh, you know, we, like I mentioned that GLI global is a, um, uh, kind of weighted average of already existing data we're into. Racial categories, and it's a limited number of categories, and it's not people from, um, all over the world.
And so even for spirometry, um, uh, the field is gonna be [00:24:00] considering, um, you know, what is the next best reference equation? Um, and like Meredith said, Um, you know, maybe the answer to what's the next best reference equation and having to change that constantly use reference equations. Um, and so that's where spirometry, um, could be heading in a couple of different directions.
But for those other pulmonary function tests, uh, lung volumes and diffusing capacity, uh, even more work needs to be done. And, uh, I think, uh, Um, unlike for spirometry, where there is data on, um, uh, you know, a diverse group of people, um, even though it doesn't represent the full diversity of the world, um, it's even more limited for lung volumes and diffusing capacity, where only people who were categorized as white or European ancestry are included in the reference equations.
Um, for those. So the currently recommended reference equations, um, are not [00:25:00] an average of different racial categories or a diverse group of people. And that, uh, is important to take that into account when interpreting, um, these tests together, uh, in that you might, for people near the borderlines, get one answer from spirometry about whether somebody's abnormal or normal or mild or moderate or severe.
Okay. sir. And get a different answer from one of these other tests like lung volumes and diffusing capacity. And so we do need more, uh, diverse population data for lung volumes and diffusing capacity.
Dr. Meredith: And I think there are efforts underway to try to gather that data internationally, but of course, uh, it's not something that can be done immediately.
So while we're, while we're waiting for those, those data, we're trying to think about approaches to use the data we have in hand.
Dr. Amy: Well, I mean, that's, that's great. I think it's such a wonderful story and how you both have worked so hard and making a change and then [00:26:00] implementing it, um, at your own center level.
So I think there's. To do, but it was just wonderful to have this discussion today. So thank you, Dr. Bakhtrad, Dr. McCormick for this enlightening discussion on pulmonary function testing, um, and, uh, race, neutral testing. And thanks to our listeners for joining us today. If you haven't yet done so you can register for the ATS 2025 international conference in San Francisco.
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non: Thank you for joining us today. To learn more, visit our website at thoracic. org. Find more ATS Breathe Easy podcasts on Transistor, YouTube, Apple Podcasts, and Spotify. Don't forget to like, comment, and subscribe so you never miss a [00:27:00] show.