A “race equation” baked into a standard medical test is hurting Black patients, but most hospitals are still using it

In medical school, Aaron Baugh, like most doctors in training, was taught that Black people have smaller lungs than white people. His professors explained that it came down to evolution and body proportions.

A spirometer measures lung capacity and helps doctors diagnose and treat most lung diseases, including asthma, COPD, and cystic fibrosis. And for generations, it had a so-called race 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 10 to 15 percent lower than for white patients. For years, doctors believed that a race “correction” made the test more accurate.

But after becoming a pulmonary and critical care physician, Baugh discovered that historical assumptions embedded in the spirometer were not only wrong, but were based on racist science that can be traced back to American slavery. And they were leading to misdiagnoses in thousands of Black patients, including military veterans. 

“This is not a small test,” Baugh says. “It is used in diagnosis of lung disease. It is used for job hiring. It is used for disability assignments. It is used for different medical treatments. So it can touch people in a lot of important ways if you’re doing this wrong.”

This week on Reveal, we team up with The Race Equation podcast series from the New England Journal of Medicine to examine a standard medical test with a brutal history that is harming Black patients and is still being used in hospitals across the country.