When I lived in Philadelphia, I had an allergist who would often give me lung function tests to assess my asthma-related difficulties. The test always registered as normal, even when I was clearly unwell, and in fact, sometimes it came out above average, which she said was odd for an asthmatic. I have always hated having to prove I have a chronic condition, and I feel anxious whenever I must see a doctor for a flare-up, worried I’ll be told it’s not that bad or I’m just fine. I have put off medical care sometimes just to avoid dubious looks from providers.

A lung function test, also called spirometry, measures how well a person’s lungs are working. By having the patient breathe into a device that records the amount and speed of air they inhale and exhale, doctors can assess conditions such as asthma, chronic obstructive pulmonary disease (COPD), and other breathing issues.

For decades, lung health tests have used different “normal” standards based on race, leading to different treatment for Black patients, like myself. As it turns out, these tests classify lung function differently for Black and White people, often causing Black patients to be underdiagnosed or undertreated.

White Fists on the Lungs of Health Care: New Research

A groundbreaking study by Diao and colleagues, published this year in The New England Journal of Medicine, showed that gold standard race-adjusted equations in lung-function tests underestimate the severity of Black patients’ lung problems and overestimate the severity of White patient lung problems, reinforcing inequalities in healthcare. These race-based calculations normalize lowered lung function for Black people, making them seem healthier than they are. In contrast, White people’s results are based on more sensitive classifications, leading to better access to care, support, and disability benefits.

For Black people, the predicted normal values are adjusted to be about 10–15% lower than for White people, which can cause healthcare providers to overlook signs of lung diseases like asthma, cystic fibrosis, or COPD for Black people.

18th Century Racism: Alive and Kicking

This race-based system was based on false notions that Black people had naturally deficient lungs. Thomas Jefferson, in his 1785 Notes on the State of Virginia, described what he believed to be a difference in the lungs of enslaved people compared to White colonists, stating the “difference of structure in the pulmonary apparatus” was a justification for slavery, arguing that forced labor would “vitalize the blood” of Black slaves.

Jefferson’s claim was built upon by other researchers, including Samuel Cartwright, the physician who invented the term “drapetomania,” and John Hutchinson, an English researcher who invented the spirometer. By the early 20th century, the idea that there were racial differences in lung capacity was widely accepted as fact.

However, there is no legitimate physiological or genetic rationale for why there would be innate racial differences in lung function, so this idea is scientifically unjustified. Rather it is a harmful and false medical stereotype that has led to incorrect clinical assessments that impact millions of people, including children (Non et al., 2023).

Black Children Suffer Double the Rate of Asthma

About 4 million children in the U.S. have asthma. The percentage of Black children with asthma is far higher than White children—more than 12% of Black children in America suffer from the disease, compared with 5.5% of White children. They also die at a staggeringly higher rate, with Black children 8 times more likely to perish from asthma.

Further, struggling to breathe can be a cause of Mental health problems, like depression and anxiety. Adolescents with asthma have a significantly increased risk of developing panic disorder (Wu et al., 2022), and a European study found that those with asthma were far more likely to experience suicidal ideation and suicide attempts than those without — an association that held up across age groups, even when controlling for demographics, socioeconomic status, Mental health, smoking, and stressful life events (Barker et al., 2015).

Source: Rena Schild / Shutterstock

Differences in income, access to care, and housing have all been implicated as reasons for this health disparity, but the impact of biased medical tests on disparities may be a larger part of the problem than anyone has realized.

Blood Oxygen Miscalculated in Black Patients

It’s not just historical notions that cause diagnostic problems. Racism is systemic. As such, often healthcare equipment is just not designed with people of color in mind. For example, a recent study found that pulse oximeters systematically overestimate blood oxygenation levels in Black patients compared to White patients (Sudat et al., 2023). Even though the blood oxygen of Black patients was overestimated by only one percent, this translates to real differences in care — for example, this difference led to delays of over four hours in receiving supplemental oxygen during the COVID-19 pandemic.

One wonders if these devices were even tested on people of color at all before being shipped to doctor’s offices and hospitals. The study authors emphasized that differential pulse oximeter accuracy has the potential to worsen racial disparities for any condition, like asthma, that relies on blood oxygenation to inform clinical decision-making.

Racial Bias in Medical Technology Harms People of Color

Originally intended to improve accuracy, race-based adjustments in spirometry have instead had harmful effects on patients’ health, job opportunities, and financial stability. Experts now call for “race-neutral” tests to help end these injustices, highlighting the need to change a system rooted in outdated, biased ideas. By justifying biased standards as medically necessary, the system has perpetuated racist practices rooted in false beliefs of racial differences in lung function that date back to 18th-century assumptions. Diao’s study underscores the importance of revising medical practices and technologies that have disadvantaged Black patients for decades.

Improving biased healthcare technology is not just a technical fix but an urgent step toward justice and ending fatal medical biases. There is a moral responsibility to eliminate unexamined racist practices to ensure fair, equal care for everyone. It is also a jarring reminder that when we are too quick to accept practices based on racial stereotypes, we compromise the health and well-being of vulnerable people, including our children.