For almost two years, everyone has ignored an important “health equity” story affecting 87% of Americans. It concerns the medical definition of chronic kidney disease (CKD), which is an impairment of the kidney’s ability to filter waste, toxins, and excess fluids from the blood. Affecting approximately 37 million US adults, the disease can lead to dialysis, kidney replacement, and death.

Physicians and health care providers rely on laboratory measurements of glomerular filtration rate (GFR) to diagnose CKD and to qualify patients for treatment, Medicare-paid education, referrals to a nephrologist (kidney specialist), and kidney transplants. GFR is usually estimated from a chemical in the blood called “creatinine.” High creatinine levels signify that the kidneys are not functioning well. Nearly 250 million creatinine measurements are made each year in the US.

On average, blacks have higher creatinine levels than non-blacks with the same kidney function. Their higher creatinine levels may arise because blacks in America have greater average muscle mass than non-blacks.

For over two decades, the formulas used to estimate GFR have included a correction for the higher creatinine concentrations in blacks in order to obtain the very best estimate of their directly measured GFR (the gold standard of kidney function.) This correction factor increased black GFR between 16% and 21%.

Image: Black and white healthcare providers by freepik.

One might assume that CKD and GFR would be defined with scientific impartiality. However, one consequence of the race adjustment is that, at the same blood creatinine level, a black patient might not receive the same kidney treatment as a non-black patient. Thus, whites with lower creatinine numbers will receive medical intervention, while blacks will not.

This has led medical students and physicians-turned-activists to cry discrimination. Activists collected petitions at major hospitals calling to remove the race correction. Medical journals published no fewer than fifty commentaries, editorials, and articles calling for its abolition. Print and internet news articles dutifully reported that the formulas were racist.

There was little published opposition once the race correction was framed as a civil rights issue. Scientists’ reticence to speak out was not unexpected, given that research funding requires nearly unanimous endorsement from the National Institutes of Health (NIH), and no scientist can risk alienating even one grant reviewer.

The government also became involved. In a 2020 letter to the Agency for Healthcare Research and Quality, senators Elizabeth Warren, Ron Wyden, and Cory Booker and Representative Barbara Lee expressed their concerns that GFR race-correction and other race-based algorithms risked embedding racism into medical practice. That year, Ways and Means Committee Chairman Richard E. Neal (D-MA) sent letters to the American Society of Nephrology (ASN) and other medical organizations questioning their use of race in clinical algorithms.

Importantly, none of the petitions, none of the government actions, and none of the medical and news articles acknowledged one simple fundamental fact: blacks and non-blacks received exactly the same diagnosis and medical treatment based on their very best estimate of directly measured GFR (the gold standard, which is not necessarily the same as laboratory creatinine measurements.)

Nevertheless, in response to pressure from students, activists, and Congress, the National Kidney Foundation (NKF) and the American Society of Nephrology (ASN) redefined GFR (kidney function) by recalculating the GFR formula without the race correction. The only reasons given for this change were that “race is a social, not a biological construct” and that race, as used in the original equations, ignores “the substantial diversity within self-identified black or African American patients and other racial or ethnic minority groups.” Notably, the organizations did not provide any evidence of improved health outcomes.

In fact, removing race from the equation distorted (biased) the estimated GFR to favor CKD diagnoses in blacks and disfavor CKD diagnoses in non-blacks (bias is the difference between estimated and actual GFR due to a formula defect). Nevertheless, the National Institutes of Health and other scientific organizations gave the new race-free GFR formula their blessings. The NKF/ASN push for the immediate adoption of their race-free GFR estimate by clinical laboratories resulted in 70% acceptance as of October 2022.

The ASN/NKF decision is projected to have a substantial impact on white and other non-black CKD patients. When fully implemented, the race-free GFR replacement formula is expected to negate CKD diagnoses in 5.51 million non-black adults who likely have CKD and reclassify CKD to less severe stages in another 4.59 million non-blacks—all in order to expand treatment eligibility to 434,000 blacks who are not likely to have CKD and to 584,000 blacks previously diagnosed with less severe CKD.

In addition, 92,000 non-blacks are expected to be denied nephrologist referrals and fistula placements (preparation for dialysis) so that these services can be extended to an additional 59,000 blacks who are less likely to need them. Similarly, Medicare coverage of medical nutrition therapy and kidney disease education will be withheld from 1.9 million non-blacks so that an estimated 206,200 additional blacks gain access.

There is, of course, a financial angle. These bureaucratic changes will reduce overall treatment costs by reducing total patient load by 5.08 million CKD diagnoses and reducing CKD severity in 4.01 million patients. Ending or reducing diagnoses will eliminate 70,000 nephrologist referrals and fistula placements, 856,000 medical nutrition therapies, and 64,800 kidney disease education programs.

The new race-free formula fails the NKF/ASN assurances that any change in GFR would be unbiased (in fact, it was purposely biased to favor black and disfavor non-black CKD diagnosis), based on rigorous science (none presented), and acceptable performance characteristics (11 million misdiagnoses is unacceptable) and would not disproportionately affect any one group of individuals (whites and other non-blacks disproportionately affected).

These broken promises are particularly egregious that there exists a much better (less biased) estimate of GFR using separate formulas in blacks and non-blacks. However, the creators of the race-free formula (the Chronic Kidney Disease Epidemiology Collaboration) refuse to release it, presumably because it acknowledges racial differences.

These and other issues regarding race and CKD were recently published in an article I wrote that appears in the peer-reviewed science journal Cureus. It is no surprise that Kidney Medicine, which NKF publishes, and the three medical journals that ASN publishes were unreceptive to this paper, its support of the original race-corrected GFR formula, and its criticism of the race-free formula.

Although I’m not retired, I spent my career as a biostatistician, and I’ve published over 170 scientific papers in peer-reviewed medical journals. With that background, I see the CKD changes as a harbinger of ever-more dangerous race-driven changes in medical treatment, changes driven by politics rather than science. I believe the NKF/ASN decision is scientific malfeasance that endangers public trust in our medical institutions.

Recent Gallup surveys show the public holds medical professionals in high regard (≥high honesty/ethical standards in nurses reported by 79% of respondents), medical doctors (62%) and pharmacists (58%) compared to journalists (23%), lawyers (21%), and members of congress (9%). This legacy shouldn’t be squandered.