Scientific impartiality is supposed to prevent politics from influencing the country’s health care decisions. This is no longer true for chronic kidney disease (CKD), which is the impaired ability of the kidneys to remove waste, toxins, and excess fluids from the blood. This condition affects more than 35 million U.S. adults. However, in the case of CKD, racial politics have trumped scientific impartiality — and with the blessing of the National Institutes of Health and the leadership of many medical organizations.
The diagnosis and treatment of CKD are guided by an overall measure of kidney health known as the glomerular filtration rate (GFR). Although GFR can be directly measured in a hospital or research clinic (the gold standard), in the doctor’s office it is mostly estimated based on creatinine levels in the blood. For over two decades, creatinine levels have been assessed in routine screenings and treatment; higher levels of creatinine in the blood are associated with lower GFR. The lower the GFR, the greater the severity of CKD.
On average, American black adults have higher blood creatinine than non-blacks who have the same level of kidney function. A “plausible biological explanation” is that creatinine is secreted into the blood by muscle cells, and the average American black adult has more muscle than the average non-black adult. In the past, this difference in creatinine levels was accounted for by a race-correction factor in the GFR formula. This is why blacks tend to have between about a 16 and 21 percent higher GFR than non-blacks with the same creatinine concentrations.
This correction factor was meant to provide black and non-black patients with the same CKD diagnosis and treatment based on the best estimate of their directly measured GFR, which might be different from their creatinine levels. This is why laboratory reports used to show two different categorizations of GFR estimates — one for African Americans, and one for others.
Students and activists successfully petitioned major hospitals to remove the race correction, which they characterized as being “rooted in historical injustice and a legacy of justification for colonization, slavery and genocide.” In addition, many protesters asserted that the correction factor promoted racism by perpetuating false beliefs that bodies or kidneys are biologically different in blacks and non-blacks. A biological race correction also violated the protesters’ fundamental premise that racial health disparities are largely due to racism. The congressional House Ways and Means Committee also applied pressure to the medical establishment for the removal of the correction factor. Internet articles and other media frequently repeated the claims that race correction was racist.
Until recently, no one challenged the legitimacy of these claims.
No Longer Siding with Science
The National Kidney Foundation (NKF) and the American Society of Nephrology (ASN) are two preeminent national organizations representing kidney patients and their treatment providers. In 2020, the NKF/ASN formed a Task Force on Reassessing the Inclusion of Race in Diagnosing Kidney Disease, because “recent calls for social justice reform have galvanized segments of the medical community into further discourse and action toward achieving greater health care equity, including the assertion of race as a social, nonbiological, construct.”
They decided to remove race from the formula for estimating GFR. Their decision was driven not by scientific discussions on the clinical utility of self-identified race, but rather by the statistically irrelevant claim that “race” had no biological basis.
The exclusion of race appears to have been a preconceived, agenda-driven choice and not the consequence of rigorous statistical evaluation. Excluding the race coefficient produced a statistical bias that promotes CKD diagnosis in low-risk blacks at the cost of restricting diagnosis in non-blacks. What’s more, the task force ignored their charge to ensure the estimates would: 1) Be “based on rigorous science” (but no such evidence was ever presented), 2) provide an “unbiased assessment” of kidney function (which turned out to be admittedly biased), and 3) not disproportionately affect any one group of individuals (even though it leaves non-blacks medically disadvantaged).
The Dangers of a Politicized Medical Field
The task force’s push for the immediate adoption of their race-free GFR estimate by clinical laboratories resulted in a 70 percent acceptance as of October 2022. When fully adopted, the race-free GFR replacement formula is projected to eliminate — not cure — CKD diagnoses in just over 5.5 million U.S. whites, Hispanics, Asians, and other non-black adults who likely have CKD, as well as reclassify previous CKD diagnoses as less severe in another nearly 4.6 million non-blacks. This will all be done to expand treatment eligibility to 434,000 blacks who are not likely to have kidney disease in the first place and to 584,000 blacks previously diagnosed with less severe cases.
By removing the race-correction factor, the task force successfully redefined CKD from a disease affecting blacks and whites similarly in the 2015-2018 National Health and Nutrition Examination Survey (6.4 percent and 7.7 percent respectively) to one disproportionately affecting blacks (9.3 percent and 5.8 percent respectively). Even before the task force recommendations, many blacks were more likely than whites to receive drug treatment, undergo additional testing, and see a physician specializing in kidney care. Blacks were more self-aware of their CKD condition, and treating physicians were also more aware of their black patients having CKD.
Exaggerating the CKD prevalence in blacks could exacerbate treatment differences between blacks and non-blacks. Indeed, greater access to treatment opportunities is the most commonly cited benefit of the race-free estimate of GFR. But decreased access to treatment in non-blacks is never discussed.
These and other issues regarding the removal of race from the diagnosis and treatment of CKD are discussed in-depth in a peer-reviewed article published in the science journal Cureus. This article emphasizes that the purpose of the race-correction factor has always been to best estimate “measured GFR” in a clinical setting based on biomarkers, sex, age, and patient self-report, including self-reported or clinically assessed race. The race-correction factor allows for a more accurate prediction of GFR.
We Can’t Ignore the Warning Signs
Scientific consensus committees play an important role in synthesizing medical literature into actionable treatments via rigorous critical literature review. In contrast, the NKF/ASN task force cited race as “a social and not a biological construct” and the “national call for re-evaluation of the use of race in clinical algorithms” as reasons for removing the race-correction factor. The adoption of the race-free GFR estimate appears to have been a fait accompli and the creation of a task force the means to this end.
While their decision may have been uncritically embraced by the National Institutes of Health and others, it violated the physicians’ duty to base treatment decisions on the best available science — and to deliver the best health care to all.
The issues raised go way beyond CKD. The new race-free GFR estimate may be a harbinger of race-driven changes in medical treatment. When medical practices are dictated by politics rather than science, we endanger public trust in our institutions.
A recent Gallup poll shows Americans have heretofore held members of the medical profession in much higher regard with respect to honesty and ethical standards than journalists, lawyers, and members of Congress. This is a legacy the medical establishment would be foolish to squander.
