The first sign that something was wrong with Curtis Warfield came in 2005, when protein was detected in his urine during a routine medical exam. In 2012, Warfield was diagnosed with stage 3 kidney disease. Two years later, he started dialysis.
„When you get a diagnosis, you're sitting there like a deer in headlights. You don't know what's going on. You don't know what's going to happen next,“ Warfield said. said. „You know, you have this disease.“
Warfield, a black man, was 52 years old, in good health, and had no family history of kidney disease. As his symptoms worsened and he considered treatment options, he unknowingly experienced a form of racism. It was a formula that took into account his race when estimating kidney function.
That equation, called estimated glomerular filtration rate (eGFR), is a key variable that helps determine treatment for the estimated 37 million kidney disease patients nationwide. The eGFR formula estimates how well a person's kidneys are filtering blood, taking into account a person's age, gender, and level of creatinine, a waste product naturally produced in the human body and excreted by the kidneys. To do. But it has long involved a controversial variable: race.
If a person identifies as black, the equation adjusts the score and increases the score. Other races are not included in the calculation. As a result, black people have higher eGFR scores than other races. These scores, which estimate how well your kidneys are working, influence the treatment your doctor recommends. The lower the score, the more likely the patient is to start dialysis or even receive a kidney transplant.
As the disparities faced by Black people with kidney disease have become widely studied, race-based eGFR has become increasingly important to nephrologists, high-profile kidney disease organizations, and, importantly, the biological differences that differentiate Black people. It was increasingly challenged by medical students who questioned educators about the rationale. blacks and non-blacks.
Warfield has continued to advocate for others with kidney disease since receiving a transplant in 2015. He joined a multi-organizational task force led by the National Kidney Foundation in 2020. The task force spent months digging into the issue and challenging racial inclusion. and ultimately initiated his two new equations for estimating kidney function.
This fall, a new race-neutral equation was announced. And in February, the United Network for Organ Sharing (UNOS), the nonprofit organization that manages the U.S. organ donation and transplant system, announced that was suggested End the use of racialized eGFR and adopt race-neutral eGFR. As a result, kidney care in the United States has reached a crossroads that overcomes deeply entrenched institutional racist equations.
Removing racial factors from kidney estimates is an important step in reducing disparities in kidney disease and treatment, according to experts on the National Kidney Foundation task force. Black Americans are disproportionately at risk for diseases that cause kidney disease, such as high blood pressure, diabetes, and heart disease. According to the National Kidney Foundation, black people make up less than 14% of the U.S. population, but they account for 35% of people receiving dialysis.
“Black people are much less likely to be referred for a transplant even if they are on dialysis. If referred, they are much less likely to be listed. Once listed, they are much less likely to be offered a kidney transplant. There are disparities at every step,“ said Rajnish Mehrotra, M.D., chief of nephrology at Harborview Medical Center and professor of nephrology and medicine at the University of Washington.
These differences are the basis for an increase in questions from medical students over the past few years, especially regarding what students were learning about the equations for assessing kidney function, Mehrotra said.
„They were taught in class that there was an equation that reported different numbers for black people and non-black people. And they were like, 'What's the evidence that there's a difference?' , challenged that premise, Mehrotra said. “And the deeper we dug in terms of looking for evidence to support racially differentiated coverage, the more we came to the assessment that the evidence to support it was not strong at all.”
The University of Washington School of Medicine, where Mehrotra works, became one of the first institutions to eliminate the racial variable in the eGFR equation in June 2020.
But so too does a broader movement involving the major professional societies of nephrologists, the National Kidney Foundation, the American Society of Nephrology, as well as patient advocates (including Warfield), clinicians, scientists, and laboratory technicians. It was progressing. The meeting will be held with the aim of phasing out racist eGFR and supporting a race-neutral approach.
In June 2021, one year after Washington Medicine withdrew its racialized eGFR, a task force formed by these organizations Interim report I question the use of race as a factor in diagnosing kidney treatment.
The eGFR race variable was created based on research from the 1990s, the report said. “Dietary Modification in Renal Disease (MDRD)” published in 1999. study The research team was one of the first to include blacks, and the initial equations for estimating renal function were based entirely on information from white male patients, which resulted in black adults having lower serum creatinine levels than white adults. were also found to be high, the task force authors wrote in their report. report.
At the time of the MDRD, making mathematical adjustments based on race was considered progress because including Black people in research was itself progress, the report said.
But within MDRD there is a troubling justification for higher creatinine levels among black people. Previous research has shown that „on average, black people have more muscle mass than white people.“ His three studies cited there are: 1977, 1978 and 1990compared various health indicators, including serum creatinine kinase and whole body potassium levels, between black and white study participants. Both of these studies say that a different reference standard is needed for black people and attribute the difference in results to differences in racial biology.
Today, those conclusions would be called into question.
„Our understanding of race has evolved over the past quarter century,“ said Paul Palefsky, president of the National Kidney Foundation and a professor at the University of Pittsburgh, one of the lead organizations on the task force. said the M.D. Ph.D. “Rather than being based on biology, race is more of a social construct than anything else.”
In September 2021, the task force published two new equations to estimate kidney function. Neither uses race as a factor. One is very similar to racialized eGFR, which measures creatinine. Another formula adds his second test, which measures cystatin C, another chemical in the blood that acts as a filtration marker.
Creatinine testing is available at virtually every testing facility nationwide, but cystatin C is not, so both formulas are recommended. This increases prices and reduces access to testing. Palevsky said the process of transitioning testing operations to the new standards is underway and he expects major testing agencies to make changes in the coming months.
„In medicine, the typical time between the publication of clinical practice guidelines and recommendations and the actual initiation of clinical care is about 10 years,“ Palewski said. „What we're seeing in this case is a very rapid implementation of a new equation.“
Although the new equation is slightly less accurate than the old one, Palevsky and Mehrotra agree. However, estimates are just estimates and should be used as part of a more comprehensive clinical analysis of a person's health and needs.
And while racial disparities in health care in general continue to be studied and understood, the impact of taking race into account in medical decisions can have corrosive effects beyond individuals and their diagnoses. Parekhsi said there is. „When we teach medical students and residents, when we use race-based algorithms, we are reinforcing to them this notion, this false notion, that race is a biological determinant of disease. But that's actually not the case,“ Palewski said.
Systemic racism impacts the health outcomes of Black people in a variety of ways. chronic stress From people who have experienced racism to a limited number of people access to healthy food to the prejudice of medical provider. These problems are deep-rooted and require unique and lasting solutions.
But the new eGFR equation is a step in the right direction, Palevski said.
“Will the problem of disparities in kidney care be solved? I think we are deluding ourselves to think that simply changing the equation will solve much deeper problems. '' Palevski said. “Certainly, simply changing the equation will not solve the problems of disparity, many of which are rooted in historical racism.”
These disparities will only be meaningfully reduced by large-scale investments in the health of poor communities. But eGFR formula is still a meaningful step for Black people with kidney disease. Warfield said the benefits of the new eGFR equation extend beyond the equation itself.
“At least it opens eyes and doors to other disparities that are happening in the kidney field and gets people talking and opening their eyes to what's going on,” Warfield said. „It's good to know that patients now have a seat at the table and are being heard, not just decisions made by the medical community.“