In 2018, my dad died of peritonitis, a common infection in people who are on peritoneal dialysis therapy. My dad was diagnosed with end-stage renal failure many years before he passed. But, a recent reckoning in medicine points to a dark reality in calculating kidney function in Black American patients, something medical schools and the scientific community are only now addressing. 

Ever wonder why there are so many dialysis clinics in Black communities?

Black Americans experience kidney failure almost four times as often as white Americans, are less likely to receive referrals to specialists, and are significantly less likely to receive kidney transplants than white patients.

To assess kidney function and track chronic kidney disease, health care providers commonly use a measure called estimated glomerular filtration rate, or eGFR. But, when it comes to Black patients, the tool adjusts for race—and here’s where it becomes truly frightening. 

According to the eClinicalMedicine journal, if the eGFR equation did not include a race adjustment, 31,000 more Black Americans would become eligible for a kidney transplant, 300,000 more would qualify for a nephrologist referral, and 3.3 million more would reach the threshold for stage 3 chronic kidney disease.

“As medical students, we’re explicitly taught to think about race in this way, that there’s some underlying biological difference at a population level,” Jennifer Tsai, a resident in Yale’s Department of Emergency Medicine and lead author of the study. “As we show in this study, there are many reasons why we think this is not valid.”

So where did all of this come from? Why is race a factor in the eGFR? Well, the medical community has wrongly claimed for decades that Black people have a higher muscle mass than other people. And this misinformed idea dates back to slavery. 

“It goes back to slavery days, where you would buy Black men based on their muscles,” medical student Bisrat Woldemichael, now a resident at Emory University, said during a discussion on racism in medicine at University California, Davis, during rounds in 2020. “I asked, ‘Why did we accept that, and why do we still continue to use it?’ It affects how Black folks get new kidneys, and that is, to me, horrific.”

Woldemichael’s comments lead to the development of a task force at UC Davis. 

The eGFR was developed in 1973, based on data from 249 white men. In 1999,  Andrew S. Levey, emeritus chief of nephrology at Tufts Medical Center, and his colleagues included 197 participants who self-identified as Black. By 2009, Levey, Tufts nephrologist Lesley Inker, and several other investigators studied 8,000 people to develop the equation, 30% were Black. It was determined that Black people had a higher creatinine level.

“I like to say that the eGFR was the medical students’ George Floyd,” Jann Murray-García, a professor at the Betty Irene Moore School of Nursing at UC Davis and member of the task force, tells UnDark. “It was medical students who pushed to urgency what we have lived within medicine.”

As it turns out, 2020 was the year when many health inequities were exposed, but the eGFR came under scrutiny initially in 2019, with petitions and outcry from residents. A year later, things exploded. 

It was quite a movement,” Chi-yuan Hsu, chief of nephrology at the University of California, San Francisco tells UnDark. Hsu says, “I personally wanted race out of the equation.”

Today, both the National Kidney Foundation and the American Society of Nephrology have task forces to examine the data. But changes are slow to happen regarding race modifiers. 

The New England Journal of Medicine ran a piece in 2020 that clearly highlighted the shaky foundations of the current practices.

“Our understanding of race and human genetics has advanced considerably since 2003, yet these insights have not led to clear guidelines on the use of race in medicine. The result is ongoing conflict between the latest insights from population genetics and the clinical implementation of race,” the Journal reads. 

The good news is that, despite the decades of inaccurate or biased determination of creatinine levels in Black patients, a new kidney marker is in development—one that measures kidney function regardless of race. 

The good news? In Sep. 2021, the national task force published its conclusions and recommended that all institutions and laboratories convert to a new kidney equation. The race-free calculator is called the eGFR 2021 CKD-EPI creatinine equation, and it pulls data from over 20 studies at several institutions to validate accuracy, UnDark reports. 

Next up, scientists have begun a study using cystatin C and creatinine as markers for kidney function. The study, launched in 2021, omits race from calculations—meaning it is more accurate for Black patients. 

But, the fact remains, much of the damage has been done.

According to Healio, Black men who receive hemodialysis in communities with a higher proportion of Black residents experience worse outcomes than those who receive treatments in communities with fewer Black residents—including higher rates of hospitalization and mortality.