Last month, a federal judge in New Jersey considered the plea of an inmate who claimed his kidney problems made Covid-19 especially dangerous for him. The man, Maurice McPhatter, 49, was one of more than 20,000 federal prisoners who have sought early release during the pandemic. Thousands have been freed through that process.
Mr. McPhatter, who was serving a 10-year sentence for drug trafficking, explained in a handwritten letter that he was born with only one kidney and now had a large kidney stone. Results from a blood test scored Mr. McPhatter’s kidney function as low.
But then the judge, Kevin McNulty, did something that sunk Mr. McPhatter’s chances of early release. The prison medical records contained instructions that kidney test scores for African Americans should be adjusted, using a decades-old formula that drew a distinction between races. Mr. McPhatter is Black, and the resulting “race adjustment” put his score on the healthy side of a commonly used threshold for chronic kidney disease.
“He is at no particular risk of a dangerous Covid infection,” the judge concluded in his decision on March 23, denying Mr. McPhatter’s application.
But the formula Judge McNulty used to make his decision has been discarded by a growing number of health care institutions and experts who say it can lead to misdiagnoses and inequitable care for Black patients.
The American Society of Nephrology recommended last year that it be replaced with a race-blind formula. LabCorp, the diagnostic laboratory company, has already made the switch, as has the Department of Veterans Affairs and numerous major hospital systems.
Yet during the pandemic, the older formula took on unexpected importance in at least one setting: federal courtrooms where the race-adjusted kidney score is still employed to help judges decide whether to grant medical release to Black prisoners.
It is unclear how many cases may have been decided on the basis of the old formula. But this week, lawyers for a Black inmate at the Hazelton federal prison complex in West Virginia, Jonte Robinson, filed a lawsuit in federal court in Washington, D.C., demanding that the Bureau of Prisons stop adjusting the kidney function scores of Black inmates. It also demands that the bureau re-evaluate the scores of thousands of Black inmates using a newer race-free formula.
“Jonte is demanding that the Bureau of Prisons cease using the race-based formula and take steps to rectify the harms suffered by Black individuals,” his lawyer, Juyoun Han, said in a statement. Adjusting the kidney-function scores of Black inmates amounts to “race-based discrimination,” she added. A spokeswoman for the Bureau of Prisons, Randilee Giamusso, declined to comment on the lawsuit. But she said the Bureau of Prisons “is in the process of transitioning” to the newer, race-blind formula. “We anticipate that the transition will be completed in the next few months.”
The debate over the kidney formula is part of a broader reckoning over the role of race in medicine. The race of patients is incorporated into an array of formulas that doctors use to evaluate data about everything from lung function to whether to recommend C-sections.
The history of these formulas — and how race crept into them — is varied. Some can be traced to blatantly racist origins. Others began as well-intentioned attempts to incorporate data from Black patients into diagnostic formulas.
For decades, the kidney function formula has involved measuring the blood levels of creatinine — a waste product produced by muscles. Higher creatinine levels suggest that the kidneys are struggling, translating into a lower kidney-function score.
One of the early kidney formulas relied on data from 249 white men. Then in 1999, a group of researchers proposed a new formula that would include data from Black patients, men and women.
The group’s data — as have some subsequent studies — indicated that African-American adults tended to have higher creatinine levels than white Americans — even when actual kidney health is similar. Theories abound as to why. Some researchers speculate that variation in diet or muscle mass might explain the higher levels. Others have pointed to demographics: Many of the Black participants in one key study were poor and in ill health.
Armed with this data, the researchers created a new formula that called for multiplying the kidney-function scores of Black patients by a factor of 1.2. They reasoned that the resulting higher kidney function score would be more accurate, and reduce the likelihood of overdiagnosing kidney disease in Black people.
The medical establishment by and large agreed, and the formula became standard for many lab companies and hospitals.
But critics said the higher kidney function scores masked actual kidney disease in Black patients, delaying referrals to nephrologists or preventing patients from getting onto kidney-transplant lists.
In recent years, that criticism has grown louder as a younger generation of doctors and kidney experts has argued that the race-based formula perpetuates a history of racism in medicine. They have said that focusing on a patient’s race conceals the socioeconomic, environmental and genetic factors that can contribute to disease.
“Race should not be used to make any biological inferences about individuals,” a group of doctors wrote last year in a scientific journal about the kidney formula, which they said might contribute to racial stereotypes and health inequities.
Using race to score kidney function is especially fraught because kidney disease disproportionately affects African Americans, who are more than three times as likely as white Americans to have kidney failure and need dialysis or a transplant. That is partly because diabetes and hypertension — which African Americans suffer at high rates — can increase the risk of kidney disease.
Still, some kidney specialists have defended the contested formulas that use race adjustments, saying they tend to provide more accurate measures of kidney function than those that are race-blind. These specialists assert that ignoring higher baseline creatinine levels in many Black Americans will lead to over-diagnosing kidney disease in them, limiting treatment options for other illnesses. Patients with low kidney-function scores are also often ineligible for, or given lower dosages of, certain lifesaving drugs, including antibiotics, chemotherapy and diabetes medication. That’s because certain drugs may prove too damaging to a patient’s kidneys, among other dangers.
Despite some dissent, there has been a growing medical consensus that adjusting kidney function scores according to a patient’s race no longer makes sense when other formulas that do not include race are available.
“It just has become unacceptable now to have race in the equation,” noted Dr. Neil Powe, who was co-chair of the task force of the National Kidney Foundation and the American Society of Nephrology, which recently recommended discarding the race-based algorithm and replacing it with the new race-blind one.
This debate seems to have hardly reached federal judges who were inundated over the past two years with requests from inmates for early medical release because of Covid-19. Given the crowded conditions and limited access to medical care inside prisons, the stakes were high.
A review of medical release cases suggests that many judges ruled on the basis of spotty medical records — sometimes little more than a few blood tests — and often without input from doctors who might have examined the inmate. Medical records before incarceration were often unavailable.
To make decisions, many judges turned to the website of the Centers for Disease Control and Prevention, where they found a long list of comorbidities that made Covid-19 especially dangerous, including diabetes, obesity and chronic kidney disease. Sometimes their rulings turned partly on whether an inmate had any of these risk factors.
It’s unclear exactly how many of these prison cases turned on the question of kidney disease. But one attorney’s survey of federal release orders indicated that kidney disease came up dozens of times. The C.D.C. estimates that some 37 million Americans have chronic kidney disease, and that most are unaware of it.
In the case involving Mr. Robinson, the inmate who filed the lawsuit Wednesday, a kidney-function score that had been race-adjusted was clearly a factor in the judge’s review. Mr. Robinson has served 17 years of a 25 year sentence for crimes including aiding and abetting a double murder.
“Where I am getting hung up and have concerns is with respect to whether Mr. Robinson does in fact have chronic kidney disease,” Randolph D. Moss, a federal judge in Washington, D.C., said last year during a telephone hearing.
Mr. Robinson’s raw kidney function scores ranged from 56 to 58, and a cutoff point of 60 is often used to diagnose kidney disease. A nurse who worked in the federal prison system told the judge that because Mr. Robinson is Black, his score needed to be adjusted upward, which would place it above the threshold.
Judge Moss declined to release Mr. Robinson, now 40. In a decision written in April 2021, he acknowledged that the Bureau of Prison’s use of the race-based adjustment “may be the subject of dispute.” But he said he was left without clarity on whether Mr. Robinson even had kidney disease.
“Absent further evidence, the Court cannot rely on the C.D.C.’s caution regarding chronic kidney disease (which Robinson may or may not have) alone,” the judge wrote.
In an appeal filed last year, Mr. Robinson’s lawyer pointed out the racial consequence of the old formula: “If Mr. Robinson were white his medical data would indicate that he was suffering from chronic kidney disease.”
He lost the appeal.
