For years, a number of common diagnostic tests, for heart problems, kidney disease, even pregnancy, have been adjusted based on the belief that a patient’s key bodily functions can vary significantly depending on race or ethnicity.
The practice, though, is facing new pushback amid concerns that race-based tests can downplay the severity of illnesses in Black patients, potentially reducing their access to more aggressive treatments that might protect their health or even save their lives.
“The use of race has the potential to worsen health care disparities by race,” said Darshali Vyas, a second-year resident at Massachusetts General Hospital, and coauthor of a recent paper on the practice in the New England Journal of Medicine. She and her colleagues call for doctors to reconsider the use of race corrections in a variety of medical tests.
And in September, Senator Elizabeth Warren of Massachusetts and three other members of Congress called on the Department of Health and Human Services to investigate their use, warning that they “risk embedding racism into medical practice.”
Some medical institutions have stopped using race corrections in some tests. MGH and Brigham and Women’s Hospital, for example, no longer adjust the results of a popular test for kidney functions, called eGFR. Critics worried the adjustment had tended to make kidney functions of Black patients look better, possibly concealing genuine problems and causing dangerous delays in needed medical care. Last week, a new study from Brigham and Women’s Hospital concluded that eliminating race correction in kidney disease tests would qualify up to one in every three Black patients for more advanced care — and that might result in more effective treatment of the disease.
There have been several reports of computer algorithms that produce racially biased results, such as facial recognition programs that can accurately identify white people, but not Black people. Earlier this year, a Black man in Michigan was arrested after facial recognition software falsely identified him as a criminal suspect. Such problems are usually a byproduct of the software development — in this case, using too few photos of Black people to train the software to recognize dark-skinned faces.
Racial corrections for medical diagnostic tests were created on purpose. Consider the spirometer, used to measure lung capacity. The devices often require doctors to enter the race of the patient prior to the test, based on research dating back as far as the 19th century that indicates Black people have lower lung capacity than white people.
Other examples include an algorithm used to estimate the risk to the health of a pregnant woman planning to give birth vaginally, if she has previously undergone a caesarean birth. The race-adjusted algorithm predicts that vaginal birth is more dangerous for Black and Hispanic women than for white women. But for most women, vaginal deliveries result in fewer complications and faster recovery times. Vyas speculates that the algorithm may discourage doctors from offering vaginal deliveries to women of color, who already face a higher rate of maternal mortality.
The problem, according to Vyas, is that doctors and scientists are treating race as a clear-cut biological reality when it isn’t. Research in population genetics has shown that apart from features such as skin color and hair texture, there’s not that much difference genetically among people of different races. And the differences are bound to diminish even further, as interracial marriage becomes routine in the United States.
“We know that race is not a biologic category,” said Vyas. “It’s not genetic. It’s a social construct.”
Still, a variety of tests appear to show real differences between Black and white patients. The race correction for eGFR kidney tests was developed after large-scale research studies found that the test tended to underestimate kidney function in Black people.
Another example of the biology vs. environment tension involves the coronavirus. In a new paper in the Journal of the American Medical Association, researchers from the Mount Sinai School of Medicine reported that a gene associated with higher risk of contracting COVID-19 is more commonly found in the nasal tissues of Black people than white people. This genetic difference could help explain why such a high percentage of Black people in the United States get infected.
But that doesn’t prove that race is the reason. Vyas argues scientists should look for other explanations, such as the effects of systemic racism. For example, Black people are more likely to live in poverty, which exposes them to greater health risks. Vyas also said the psychological stress of coping with constant racism could affect the health outcomes of Black patients.
“It’s not okay to just mention race without talking about racism,” Vyas said.
The lead authors of the Mount Sinai study take note of this too, arguing that environmental and social factors play a role in the activation of genes. This could explain why Black people are more vulnerable to COVID-19.
Even a physician who helped develop the race-corrected algorithm for kidney tests agreed the practice has its limitations. But Lesley Inker, director of the Kidney and Blood Pressure Center at Tufts Medical Center, cautioned that failing to take race into account could also lead to faulty diagnoses in some cases.
For example, diabetes is the number-one cause of kidney failure among Black people. But because of potential side effects, current medical practice advises not administering two of the most effective drugs for diabetes to patients with low eGFR scores. Removing race correction from the kidney test would lower the scores of Black patients and make some of them ineligible for diabetes drugs that could help save their kidneys.
“This is complex, and there’s lots of pros and cons and balancing acts which should be considered prior to acting,” Inker said.
Inker warns that giving up on these corrections too quickly might be dangerous. For instance, cardiologists have recently adopted a new way of assessing heart disease risk that takes race into account. For years, doctors have relied on data from a massive study of heart disease in Framingham, which began in 1948 and continues to this day. But the population of that study is overwhelmingly white. Now doctors supplement that data with an algorithm based on data from thousands of Black patients, and have found that the new approach is better at providing early warning of heart disease in Black people.
Melissa Simon, who heads the Center for Health Equity Transformation at Northwestern University Medical School in Chicago, said doctors need more data to understand the different health outcomes between Black and white people. In 2015, the National Institutes of Health launched a Precision Medicine Initiative that hopes to use genetic data and detailed information about a patient’s lifestyle and habits to determine the ideal course of treatment for each individual. Simon hopes that kind of highly personalized medicine could eliminate the need for race-based diagnostics altogether.