How to take race out of the equation for kidney disease diagnosis

More than 20 years ago, race, specifically Black race, was factored into the calculation to diagnose kidney disease. The race factor was believed to “correct” a previous formula to better diagnose Black patients. This adjustment had unintended consequences and contributed to under-diagnosis and under-treatment of kidney disease in Black patients.

Over the past several years, there has been an increasing focus on the influence of race and racism on accepted practices in medicine, particularly in the use of clinical algorithms, such as the calculation of estimated glomerular filtration rate (eGFR), which assesses kidney function and is reported millions of times per day in the U.S. as part of routine blood chemistry tests. Key to this reexamination is the recognition that race is a social construct rather than a biological determinant and that genetic variation is greater within, than between, racial groups. Determining kidney function based on skin color has no place in 21st century medicine.  

Although the original reasons for including the race correction were based on the science and beliefs of the day, it is an example of how healthcare in the United States fails Black or African Americans and other underrepresented communities. These inequities are particularly disturbing in kidney medicine. Patients from underrepresented communities are significantly less likely than their White counterparts to receive any kidney care and are without critical opportunities for intervention that can slow progression to kidney failure. 

The inclusion of race in the assessment of kidney function is but one of many examples across medicine of algorithms that rely on race as a factor. We in the medical community need to focus instead on solutions based in science and equity to address complex, important health issues. The sooner we all do, the better we can take action to slow the progression of all life-threatening diseases. 

Kidney disease is an epidemic that creeps up on patients with little noticeable symptoms. It affects 37 million adult Americans although 90 percent of them are unaware of its presence. An additional one-third of the adult population is at risk of developing kidney disease because they have high blood pressure, diabetes, obesity, heart disease or a family history of kidney disease, all of which are more prevalent in Black or African American communities. While kidney disease often develops unnoticed, it amplifies the risk of death from stroke and heart attack and can progress to kidney failure.

In July of 2020, the National Kidney Foundation (NKF) and the American Society of Nephrology (ASN) convened a task force to find a better and more equitable approach to diagnose kidney disease. Over the past year, the task force heard from hundreds of people, including patients and their family members, medical students and other trainees, health professionals, and scientists who came forward to share their expertise and experience. Throughout this process, a consistent message emerged: systemic racism exists in medicine, and many of our patients are worse for it. 

This week, the task force released its final report, recommending the use of a new equation to estimate kidney function based on age, sex, and creatinine levels in the blood, but without using race. Creatinine is a waste byproduct filtered by the kidneys and eliminated through urine. The task force also recommended increased use and availability of blood tests for cystatin C, as an additional reliable way to check kidney function.

We believe that this race-free approach will provide a consistent method of diagnosing kidney diseases that is independent of race with accurate, representative, and unbiased results. It also provides a standardized approach to diagnosis that can be rapidly implemented in laboratories nationwide. By using this new eGFR calculation, laboratories, doctors, patients, and public health officials can make better and more informed decisions. This is an important step to greater health equity and more personalized care for patients with kidney diseases, regardless of their race.

We know that this change will not end all health inequity, but it is the first and a meaningful step in the right direction and begins the racial reckoning in healthcare we as a country desperately need. Of course, the larger charge for us all is to address the broad factors that underlie the disparities in kidney disease, kidney care and in our society in general that are based on systemic racism and a hurtful genetic myth.

The identification of a race-free estimate of kidney function was centered on a thoughtful, data-driven decision that considered all perspectives and set us on a course to better outcomes for all patients. Our call to action is to end the discrimination against patients in underrepresented communities and demand that the medical community do better. 

We are proud that nephrology, in partnership with patients, is the first medical specialty to address and eliminate a commonly used race-based calculation, and we encourage other medical specialties to follow suit. NKF and ASN stand ready to help however we can. 

Paul M. Palevsky, MD, FASN is president of the National Kidney Foundation. Palevsky is a professor of Medicine at the University of Pittsburgh School of Medicine. 

Susan E. Quaggin, MD, FASN, is president of the American Society of Nephrology. Quaggin is the Charles Horace Mayo Professor of Medicine at Northwestern University and chief of Nephrology/Hypertension and director of the Feinberg Cardiovascular and Renal Research Institute.