New York: Racial bias built into a common medical test for lung function is likely to lead to fewer black patients receiving care for respiratory problems, a study published Thursday suggests.
Up to 40 percent more black male patients in the study could have been diagnosed with respiratory problems if current diagnostic assistance computer software were changed, according to the study.
Doctors have long discussed the potential problems caused by the race-based assumptions that are built into diagnostic software. This study, published in JAMA Open Networkoffers one of the first real-world examples of how the problem can affect diagnosis and the care of pulmonary patients, said Dr. Darshali Vyas, a pulmonary care physician at Massachusetts General Hospital.
The results are “exciting” to see published, but it’s also “what we would expect” putting aside calculations based on race, said Vyas, who authored an influential 2020 New England Journal of Medicine article that cataloged examples of how race-based assumptions are used in physicians’ decision-making about patient care.
For centuries, some doctors and others have held the belief that there are natural racial differences in health, including that the lungs of blacks were naturally worse than those of whites. That assumption ended up in modern guidelines and algorithms for assessing risk and deciding on further care. Test results were adjusted to account for, or “correct for,” a patient’s race or ethnicity.
An example beyond lung function is a heart failure risk scoring system that classifies black patients as lower risk and less likely to need a referral for special cardiac care. Another is an equation used to determine kidney function that creates estimates of higher kidney function in black patients.
The new study focused on a test to determine how much and how fast a person can breathe in and out. It is often done with a spirometer, a device with a mouthpiece attached to a small machine.
After the test, doctors get a report that has been run through computer software and rates the patient’s ability to breathe. It helps indicate if a patient has restrictions and needs further testing or care for things like asthma, chronic obstructive pulmonary disorder, or lung scarring due to exposure to air pollutants.
Algorithms that adjust for race raise the threshold for diagnosing a problem in black patients and may make them less likely to start taking certain medications or be referred for medical procedures or even lung transplants, Vyas said.
While doctors also look at symptoms, lab work, X-rays and a family history of breathing problems, pulmonary function tests can be an important part of diagnoses, “especially when patients are borderline,” he said. Dr. Albert Rizzo, medical director of the American Lung Association.
The new study looked at more than 2,700 black men and 5,700 white men evaluated by physicians at the University of Pennsylvania Health System between 2010 and 2020. The researchers looked at spirometry and lung volume measurements and assessed how many had respiratory problems based on the race-based algorithm compared to a new algorithm.
The researchers concluded that there would be nearly 400 additional cases of lung obstruction or impairment in black men with the new algorithm.
Earlier this year, the American Thoracic Society, which represents lung care physicians, issued a statement recommending replacing the race-focused settings. But the organization also called for more research, including how best to modify the software and whether making a change could inadvertently lead to overdiagnosis of lung problems in some patients.
Vyas noted that a few other algorithms have already been changed to remove assumptions based on race, including one for pregnant women that predicts the risks of vaginal delivery if the mother had a previous C-section.
Changing the lung test algorithm may take longer, Vyas said, especially if different hospitals use different versions of procedures and stroke-adjustment software.
