A scientific task force on Thursday called for the jettisoning of a common measure of kidney function that adjusts results by race, giving black patients different assessments than others.
According to many experts, the adaptation can make black patients appear less ill than they actually are. Instead, doctors should rely on a race-neutral method of diagnosing and treating kidney disease, a report from the National Kidney Foundation and the American Society of Nephrology concluded.
The specific recommended equation was described in a study published Thursday in the New England Journal of Medicine.
If adopted, the new approach would affect hundreds of millions of kidney function tests performed annually in hospitals and outpatient settings, both for acutely ill patients and as part of routine blood tests. According to one estimate, one million black Americans would be more likely to be treated for kidney disease if the diagnostic equation were not adjusted for race.
The task force report, published simultaneously in the American Journal of Kidney Disease and the Journal of the American Society of Nephrology, comes amid a national reckoning over racial health disparities caused by the Covid-19 pandemic, which has taken a disproportionate toll on people of color and highlighted the disproportionate burden of chronic disease in those communities.
“The problem is a moral one,” says Dr. Neil R. Powe, task force co-chair and chief of medicine at Zuckerberg San Francisco General Hospital and Trauma Center. “It’s time to take race out of the equation.”
Black and Hispanic Americans have long suffered from high rates of conditions such as diabetes, high blood pressure and obesity, which can exacerbate an attack of Covid. These factors can also increase the risk of developing kidney disease.
The racial differences in kidney disease are stark and well documented. Black Americans are more than three times more likely than white Americans to develop kidney failure and need dialysis or a kidney transplant.
Although black Americans make up only 13 percent of the population, represent 35 percent of Americans with renal failure. More than 90,000 Americans are on a waiting list for a kidney; almost a third is black, about as much as those who are white.
People of color and low-income Americans are less chance of good care when the warning signs first appear and chronic kidney disease can be prevented. According to a report from the Centers for Medicare and Medicaid Services, they are more likely to have kidney failure and need dialysis, and less likely to be cared for by a kidney specialist before they get to that stage.
black americans too waiting longer for an organ, and are less likely to have a kidney donated by a friend or family member, for several complex reasons.
“This new recommendation will ensure that racial bias is not introduced into clinical care so that a person will no longer be judged on the basis of race and their skin color will determine what kidney care they receive,” said Dr. Nwamaka Denise Eneanya, a nephrologist at the University of Pennsylvania and a member of the task force.
Her work suggests that current measures used to assess kidney function may underestimate the severity of disease in Black patients, delaying referrals to specialists and putting them less likely on waiting lists for a kidney transplant.
“Black individuals are inadvertently harmed because they are perceived as not being sick enough,” said Dr. Eneanya.
Other members of the task force warned that the impact of the change on patient outcomes was uncertain and called on researchers to monitor the impact.
The use of medical decision-making tools that consider race and ethnicity is not unique to kidney disease. Algorithms and calculators that doctors rely on to guide the diagnosis and treatment of many conditions — from bone density and kidney stones to cancer and lung function tests — include race as a variable, such as outlined in a paper published last year in the New England Journal of Medicine.
“Race is a social construct and not a biological one,” said Dr. Winfred Williams, associate chief of the renal division at Massachusetts General Hospital in Boston, who co-wrote a feature article about the new equations.
“It can serve as a proxy for other risk factors, including food insecurity, housing insecurity, socioeconomic deprivation, all of which can limit access to best health care practices.”
In recent months, several medical associations have taken steps to address the potential bias. In May, the American Academy of Pediatrics officially dropped practice guideline that took into account a baby’s race when assessing the risk of a urinary tract infection.
The American College of Obstetricians and Gynecologists is currently updating an algorithm that has incorporated race and ethnicity into a calculator used to determine the probability of a pregnant woman having a successful vaginal delivery after a previous cesarean delivery.
The new report that reassessed the inclusion of race in the diagnosis of kidney disease was released Thursday, after a year of work and no small amount of controversy, the authors said.
The kidneys filter toxins from the blood. The new report recommends using a new equation to estimate filtration rate using a blood test that measures levels of creatinine, a waste product made by muscles that is kept in check when the kidneys are functioning properly.
A related study, also published Thursday in the New England Journal of Medicine and cited in the report, developed and evaluated new diagnostic methods that do not include race as a variable. The researchers concluded that the new creatinine equation could be applied immediately.
But the most accurate, race-neutral way to measure kidney filtration rates would be blood tests that measure the level of another marker: a protein produced by cells called cystatin C, which is elevated when the kidneys aren’t functioning properly, researchers said.
Cystatin C tests are more expensive and not as widely available, but experts advocated making them more accessible and gradually increasing their use.