Somewhere in America This Week

Somewhere in America this week, a Black patient’s blood is drawn for a routine kidney panel. A lab tech runs the creatinine number through a formula to estimate how well the kidneys are filtering. Depending on which hospital, which lab, which piece of decades-old software is doing the math, that patient’s kidney function may come back looking healthier than it actually is. Not because of anything in their blood. Because of a box checked next to “race.”

For most of the last three decades, the standard formula for estimated glomerular filtration rate (eGFR) — the number that decides whether you get referred to a nephrologist, whether you qualify for a transplant waitlist, whether a drug dose gets adjusted — included an automatic upward adjustment for patients coded as Black. The rationale, dating to 1999, rested on old, thinly sourced assumptions that Black people have inherently higher average muscle mass, and therefore higher baseline creatinine, and therefore needed their kidney function score bumped up to avoid false positives. It was race treated as biology. It was never validated across the population it was applied to, and it was applied to nearly every Black patient in America whose kidney function was ever estimated by a lab.

The effect was not neutral. A Black patient and a white patient with the same actual kidney function could receive different eGFR scores, with the Black patient’s number quietly inflated — making early-stage kidney disease look later-stage-safe, delaying nephrology referral, delaying dialysis planning, and, most consequentially, delaying placement on the transplant waitlist. Kidney allocation in the U.S. already runs on scarcity. A formula that makes Black patients look healthier than they are functions, in practice, as a formula that makes them wait longer for a kidney that could save their life.

The Paper That Named It

The reckoning traces to a single, widely cited 2020 perspective in the New England Journal of Medicine, “Hidden in Plain Sight — Reconsidering the Use of Race Correction in Clinical Algorithms,” which cataloged eGFR alongside a handful of other formulas quietly running race adjustments with no solid biological basis. By 2021, a joint task force convened by the National Kidney Foundation and the American Society of Nephrology released a final report formally recommending immediate adoption of the CKD-EPI 2021 creatinine equation refit without the race variable, alongside expanded use of cystatin C testing to confirm eGFR results in clinical decision-making.

The correction was declared dead in a journal. Nobody sent a decommission order to every lab system, EHR build, and dosing calculator in the country.

The Fix Doesn’t Ship Itself

This is the part that doesn’t make the press release: retiring a formula in a task-force recommendation and removing it from the machinery of American healthcare are two different projects, on two different timelines. Some systems moved fast. Others — running older EHR versions, legacy lab-interface software, third-party clinical calculators embedded in decision-support tools — kept the race-adjusted formula live for years after it was declared obsolete.

The transplant system had to do something rarer still: go backward and correct the past. A national mandate went into effect January 5, 2023, requiring every transplant program to identify Black candidates whose eGFR had been race-adjusted and evaluate them for waiting-time modification, with programs required to complete documentation by January 3, 2024.

What the Correction Actually Looked Like

The numbers here are more striking than a simple “credit” implies. A 2023 UNOS report found more than 6,100 Black kidney candidates had their waiting times modified, with a median of 1.7 years of additional priority time restored. A more rigorous peer-reviewed follow-up, published in the Journal of the American Society of Nephrology in October 2025, found that 32% of Black candidate listings — 14,419 out of 44,912 — received a modification, with a median increase of 610 qualifying priority days, roughly 1.7 years, confirming the earlier figure with population-level precision.

That same 2025 study surfaced something the press release version of this story leaves out: the correction itself was applied unevenly. Modification rates ranged from 11% to 45% of eligible patients depending on the transplant center, meaning a Black candidate’s chance of getting their lost time back depended significantly on which hospital they happened to be listed at. Candidates who did receive a modification saw nearly triple the deceased-donor transplant rate compared to those who didn’t a strong signal that the correction, where it was actually applied, worked exactly as intended. Where it wasn’t applied consistently, the original harm persisted quietly.

Where MB Thinks the Formula Is Still Running

  • Legacy clinical decision-support tools and drug-dosing calculators tied to eGFR

  • Disability and insurance determinations that relied on a kidney-function value calculated years ago, under the old formula

  • Smaller and rural hospital systems running older EHR infrastructure

  • Transplant centers with lower modification rates, where eligible Black candidates may still be owed uncredited waitlist time

Sources

Vyas, Eisenstein, Jones — NEJM (2020) · National Kidney Foundation & American Society of Nephrology Joint Task Force Final Report (2021) · OPTN/UNOS policy on waiting-time modification (effective January 5, 2023) · Miller et al., “Variation of eGFR Wait Time Modifications for Black Kidney Transplant Candidates,” Journal of the American Society of Nephrology (October 2025) · JAMA/JAMA Internal Medicine studies on eGFR race-coefficient removal