Why some hospitals have stopped using race-based calculations for kidney disease
If it wasn’t for Crystal Moore’s hoodie and car, people probably wouldn’t be able to tell her life is hanging by a thread.
Her black Nissan sedan has signs plastered on the windows that read: “Kidney Donor Needed!” The signs include a picture of Moore and a QR code that leads to her profile on a kidney donor registry website. She frequently wears a black hoodie when she goes out in public – to the grocery store or to run errands – with a similar plea.
But at first glance, Moore, 59, appears healthy, especially on days she musters the energy to choose a nice outfit and put on light makeup before heading to work. Moore worked as a certified nursing assistant for 18 years before starting her part-time job as a caregiver for elderly clients in Carmel, a northern suburb of Indianapolis. She typically wraps up work by early afternoon, then rushes to take care of her mother, who has dementia, at their home in the Martindale-Brightwood neighborhood of Indianapolis.
It’s nearly a 17-mile commute, which coincides with a 17-year gap in life expectancy between the two neighborhoods – a year for each mile from the wealthy, predominantly White suburb to the majority Black and Brown neighborhood where Moore lives.
Moore’s openness about her illness gives her opportunities to share her life-or-death plea with people around her.
“I ran into this girl up here at Walgreens. And she was taking a picture of my [car] signs. She was talking about a friend of hers who had just gotten a kidney. And she asked me if she could post it on Facebook,” Moore said. “I said sure. You know, so I haven't heard anything else.”
Moore has been on the national kidney transplant list for over a year. She holds out hope that she may run into "the one" at a traffic stop or parking lot – someone who will hear her story, be moved to donate and turn out to be a match.
“I'm just asking or begging people to, if you're interested, please help me,” Moore said. “I just want to live longer so I can spend more time with my grandbabies. And with my boys, my kids, and … family members and just live life and enjoy life and travel again.”
Studies show Black patients like Moore are more likely to have kidney failure than White patients. They also make it onto transplant lists later, and once they’re on the list, they wait longer to get a kidney.
While there are many reasons for these disparities, there’s increasing awareness among kidney disease experts that the decision-making tools often used by doctors to make treatment decisions – which take into account numerous variables, including a person’s race – can contribute to delays in care and disadvantage Black patients.
It’s why the National Kidney Foundation and the American Association of Nephrology called for the removal of race-based calculations for the treatment of kidney disease in 2021. Now, a small but growing number of hospitals – most recently, the Indiana University Health system – have announced they’re taking that step.
How race-based calculations may disadvantage Black patients
Kidneys play a vital role in the body by filtering out waste and excess fluids from the blood. The tiny filters or holes in kidneys are called glomeruli.
“The kidney is basically like a vegetable colander,” said Dr. Sharon Moe, director of the nephrology department at Indiana University Health. “So, it's got little holes in it, and if the holes get damaged from kidney disease, then stuff comes out in the blood that should be staying in the urine.”
The easiest way to determine kidney health is a blood test to measure the level of creatinine — a waste product created by muscles during everyday activity. High creatinine levels signal that the kidneys are not functioning optimally and could point to renal problems. The first equation to easily capture this data and measure the filtration power of kidneys is based on a 1999 study that found Black participants had higher levels of creatinine on average. That led to the assumption that Black individuals have more muscle mass, and so, at baseline, have more creatinine in their blood.
One of the tools used by nephrologists to assess kidney function is an algorithm that gives patients a score for their estimated glomerular filtration rate, or eGFR. The higher that score, the healthier the kidney is believed to be. Algorithms were written to assume this racial discrepancy in creatinine levels. From the get-go, Black patients had their eGFR number multiplied by a factor that made their scores higher, making their kidneys appear healthier than they actually were. One study found that if the race-based adjustment is removed, as many as 29 percent of Black patients will have their diagnosis shift from early-stage to advanced disease.
And because some medicines may have an effect on the kidneys, doctors use a patient’s eGFR to determine which medications a patient receives and the proper dosage. An inaccurate eGFR may affect patients’ access to certain medications for diseases like hypertension and diabetes.
A patient also needs to have a certain eGFR score to get listed for a kidney transplant. One result of artificially inflated eGFR scores for Black patients, Moe said, is that they may not get listed as soon as they should.
“Therefore you might spend more time on dialysis before you get a kidney transplant,” she said. “Our goal is always to get a kidney transplant before ever needing dialysis.”
Moe said Indiana University Health does not have estimates for how many patients may be affected by the change to the algorithm for kidney function. And while it is not clear that this race-adjusted equation had altered the care Moore was able to receive, studies show that as many as 720,000 Black patients may be treated earlier for kidney disease – and have better health outcomes and quality of life – if race is removed from the calculations.
‘We should favor practices that may alleviate health inequities over those that may exacerbate them’
Moore was diagnosed with stage 3 chronic kidney disease in 2017. The disease progressed to stage 5 within two years – a sign that her kidneys were quickly deteriorating, on the brink of failure. The result is a host of devastating problems she lives with daily.
Every night, Moore hooks herself up to a dialysis machine for more than 10 hours. The machine infuses a solution into her body through a catheter in her abdomen to absorb waste and excess fluid in the blood and flush it out in a repetitive cycle. It’s uncomfortable, but over time she has gotten used to it and is able to fall asleep.
Many Black patients like Moore will never know the extent to which their race has influenced the way they are diagnosed and treated.
Medicine cannot be colorblind, as it’s important to understand that racial disparities in health care outcomes and life expectancy exist, said Dr. David Jones, a professor at Harvard Medical School who teaches medical ethics and studies the history of race and science.
But what troubles Jones is that race – a social construct – is used as a proxy for genetic differences when a plethora of scientific research shows there is in fact more genetic variation among people from the same race than between people from different races. Still, race-based adjustments are deeply embedded in diagnostic and treatment algorithms not just in nephrology, but also in obstetrics, cardiology, cardiac surgery, oncology, pulmonology and urology – a signal of how embedded structural racism is in many aspects of American medicine.
“If you were to say, ‘Well, this person is Black, and that person is White and therefore, I will use a slightly different diagnostic test, or I will prescribe them different doses of a medicine,’ that makes me very concerned,” Jones said.
Too often, medicine recognizes differences at the population level and then assumes that every member of that group has that risk, which is not scientific or evidence-based, Jones said. That’s what happens with kidney diagnostic equations that factor in race.
One study that makes the case for the race-based factor warns that ending race adjustments of the eGFR may result in overdiagnosis and overtreatment of Black patients – an equally undesirable outcome. The authors said that including race yielded more accurate results than excluding it. But there is also evidence that overestimation of Black patients’ kidney health can delay diagnosis and treatment, and Black people in the U.S. already have the highest rates of end-stage kidney disease and death due to kidney failure.
“As long as uncertainty persists about the cause of racial differences in serum creatinine levels, we should favor practices that may alleviate health inequities over those that may exacerbate them,” Jones and his co-authors wrote in a widely cited article in the New England Journal of Medicine.
Some medical institutions that have ended the use of the race-based equation are looking to blood components other than creatinine in an effort to achieve accurate eGFR results without factoring in race.
Underlying racial disparities in health is racism — not race
When Moore learned about race adjustments in algorithms for kidney disease, she was not surprised, having seen and experienced enough systemic racism in her life. She is more concerned with finding a donor – and in the meantime staying as healthy as possible.
“It’s hard sometimes, you know, between my job and caring for my mother, I try to find time to take care of myself,” Moore said a moment before stepping aside to throw up in the bathroom for the second time during our interview – something that happens when she hasn’t had enough to eat.
Moore also has Type 2 diabetes. When she was diagnosed with kidney disease, she said she had not been prioritizing healthy eating habits, in part because she lacked knowledge of the importance of a well-balanced diet and because it’s been difficult to manage the stress and demands of her low-wage work on top of her caregiving duties.
Studies have shown that population-level racial differences are more reflective of the experience of being Black – in other words, racism – rather than being Black itself. Things like chronic stress due to discrimination and socioeconomic problems exacerbated by historically racist policies, like redlining, play a role.
Dr. Sharon Moe of IU Health said that the process to eliminate race from the algorithm that helps guide clinical decisions for kidney disease patients took a long time and numerous analyses because they wanted to ensure the equation was balanced. Eliminating the race adjustment may not cause a huge dent in the existing disparities, but she sees it as a step in the right direction.
“Kidney disease is more common in Black patients and, now we understand, part of that is due to some genetic risk factors, but also a lot of other social and structural determinants of health [like] lack of access to health care, medication costs, insurance,” Moe said.
Jones and other experts who are calling for a reevaluation of race-based medicine recognize that while genetics can play a role, accurately capturing these genetic differences is hard. Health inequities will not be solved by simply removing race-based calculations from medicine. Part of combating structural racism is “doing the hard work,” Jones said, which includes prioritizing research into structural and societal barriers and the impact of systemic racism on people’s health.
This story comes from a reporting collaboration that includes the Indianapolis Recorder and Side Effects Public Media — a public health news initiative based at WFYI. Follow Farah on Twitter: @Farah_Yousrym.