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THE assumption that Black people have a lower level of cognitive function than white people was, until recently, built into a formula used by the US National Football League to settle head injury lawsuits. The NFL has now , but race-based adjustments in routine diagnostic tests remain pervasive in mainstream medicine. Although some scientific organisations are working to remove such adjustments, many contacted by 麻豆传媒 declined to take a stance on the issue, which is growing in prominence.

Race-norming was by psychiatrist at the University of California, San Diego, as a way to try to account for the way African American people tended to score lower than white people on cognitive tests, which are commonly used to diagnose conditions such as dementia.

Subsequent research has shown that adjusting cognitive test performance to take social factors 鈥� such as education quality- into account . Despite this, at the University of California, San Francisco, says that race-norming of cognitive tests is still widely practised by doctors in the US today, something she says is extremely problematic.

Heaton says that although observed differences in test performance between subgroups of the US population may be explained by racial discrimination, stressful life experiences, a lack of consistent access to good nutrition and healthcare, and limited educational opportunities, measuring these directly is too hard.

鈥淭hese are extremely difficult to measure, quantify and 鈥榗orrect for鈥� in interpreting test results,鈥� said Heaton in a written statement to 麻豆传媒. 鈥淭he fact remains, that a very substantial amount of variability in the test performance of normal adults can be 鈥榚xplained鈥� (accounted for) by the demographic variables of age, education, sex, and race/ethnicity (together), so our best available norms 鈥榗orrect鈥� for these characteristics.鈥�

Crude proxy

Possin disagrees with using race in this way. 鈥淩ace is a crude proxy for lifelong social experience,鈥� she says. 鈥淕enetic differences in cognition do not follow these race lines. So correcting for lifelong social experience with something very crude, like race, is not precise medicine,鈥� she says. It also perpetuates the false idea that Black people are less intelligent than white people, she says. 鈥淭hat鈥檚 a big problem.鈥�

鈥�1990s
Decade the practice of race-norming was established鈥�

Race-norming could even be exacerbating health issues experienced by people as a result of social factors. 鈥淲e鈥檙e using race as a proxy for other things, instead of measuring those things directly,鈥� says at the University of Washington School of Medicine in Seattle. For example, the assumption embedded into race-norming that Black people start out at a lower level of cognitive function than white people could make it more difficult for Black people to get diagnosed with diseases associated with cognitive decline, such as dementia, when race-norms are applied.

Possin says that to eliminate race-norming in cognitive testing, it would be helpful if prominent organisations, such as the International Neuropsychological Society (INS) and the American Psychological Association (APA), took a stance on the issue. However, both declined to do so when asked by 麻豆传媒.

鈥淐orrecting for lifelong social experience with something crude, like race, is not precise medicine鈥�

鈥淭he INS does not have guidelines nor take a stance [on] race norming,鈥� said the INS. 鈥淲e are a global organization and focus on topics that are applicable around the world.鈥�

The APA said: 鈥淭he APA has no official position鈥� on race-based norming and cognitive testing.鈥�

Race adjustments aren鈥檛 just an issue for cognitive tests. If your doctor wants to measure your kidney function, they will probably start with a test that measures the levels of a waste product called creatinine in your blood, then plug the result into an equation that calculates your estimated glomerular filtration rate (eGFR), which is the rate at which your kidneys filter waste.

The most widely used eGFR equations include adjustment for race in accordance with guidance from international non-profit organisation Kidney Disease Improving Global Outcomes (KDIGO), which suggests that laboratories should .

Similarly, (NICE) recommend applying 鈥渁 correction factor to GFR values鈥� for people of African-Caribbean or African family origin鈥�.

No evidence

The use of race or ethnicity adjustments in calculating eGFR stems from an assumption that Black people have higher average blood creatinine concentrations than white people, because they have more muscle mass on average. But race and ethnicity are social rather than biological constructs, leading .

鈥淭here is no evidence that race is related to muscle mass,鈥� says Nkinsi. The origin of this idea can be traced back to a , she says. It found that study participants who self-identified as African American had higher serum creatinine levels on average than those who identified as white. 鈥淔rom this they said, 鈥極h, well if they have a higher creatinine, it must mean that Black people have a higher muscle mass鈥�,鈥� she says.

But that study included just 1628 participants, only 197 of whom identified as African American. 鈥淚t鈥檚 based on this one observation that they found out of a very, very small population,鈥� says Nkinsi. An updated eGFR equation was developed in 2009, , however the assumption that there was a need to adjust for race was carried through from the earlier study, she says. 鈥淪o now, we have all of these aspects of medicine that are all dependent on these equations that now are being recognised to be built on faulty science.鈥�

Not just faulty, but potentially harmful. A preliminary study in the UK led by Rouvick Gama and Kate Bramham at King鈥檚 College London found that eGFR equations with race adjustments , as measured using a more invasive but more accurate method. This overestimation may have serious consequences for Black patients, says Gama. 鈥淚t could lead to delay in diagnosis of chronic kidney disease,鈥� he says, and thus delays in treatment 鈥� something borne out by UK health statistics.

鈥淚f you鈥檙e of Black ethnicity, you鈥檙e three to fivefold more likely to end up with end-stage kidney disease,鈥� says Bramham. 鈥淎lmost certainly we鈥檙e not recognising it enough.鈥� The picture is similar in the US, where, according to the National Kidney Foundation, Black and African American people experience kidney failure at .

When asked about the scientific rationale behind its recommendation to adjust eGFR for race, a KDIGO spokesperson said: 鈥淜DIGO is not in a position to comment on the rationale used to determine the adjustment in eGFR calculations.鈥�

NICE told 麻豆传媒 that it is reviewing its guidelines on calculating eGFR and plans to publish updated guidance in August 2021. However, a published in January still contained a recommendation to adjust eGFR 鈥渇or adults of African-Caribbean or African family origin鈥�. The draft guidance suggested that future research should explore the use of 鈥渇actors other than ethnicity鈥� as biological markers.

In the US, the National Kidney Foundation and the American Society of Nephrology established a task force in 2020 to 鈥渞eassess the inclusion of race in the estimation of GFR鈥�. Several medical institutions across the country, including Massachusetts General Brigham and Beth Israel Deaconess Medical Center in Massachusetts as well as the University of Washington School of Medicine, have abolished the use of race adjustment in eGFR calculations over the past four years.

鈥淢edicine dependent on these equations is being recognised as built on faulty science鈥�

Race-based diagnosis continues in other areas of medicine, however. A of about 14,000 lung function tests, led by at the University of Pennsylvania, found that removing racial adjustments from the interpretation of the tests saw the number of people correctly diagnosed with a lung defect jump from 59.5 to 81.7 per cent.

The results suggest that adjusting for race in lung function tests may underestimate the severity of lung disease in Black patients, says Moffett. 鈥淲e鈥檙e assuming that their lung function should be worse and using that as a way to approach the diagnosis,鈥� he says.

The use of race adjustment in lung function tests can be traced back to the suggestion by US physician and slaveholder Samuel Cartwright in the 1850s that . 鈥淓verything we鈥檝e learned about race in the last 50 years has invalidated this,鈥� says Moffett.

Joint European Respiratory Society and American Thoracic Society (ATS) guidelines recommend the use of . 鈥淚ngrained in lung function interpretation is the long-standing assumption that the observed differences across racial and ethnic populations is biologically based,鈥� the ATS told 麻豆传媒.

鈥淭here is increasing recognition that race and ethnicity are sociopolitical constructs which are more reflective of the differing social and environmental conditions across populations than representative of true biologic differences,鈥� said the ATS, adding that it is 鈥渃ommitted to leading action to address racism in medicine and eliminate the misuse of race and ethnicity in clinical decision making鈥� and that it has 鈥渃onvened a workshop to critically evaluate current guidelines鈥�.

Changing times

Moffett thinks race-norming adjustments should be stopped. He and his colleagues are currently developing a 鈥渞ace-free equation鈥� for interpreting lung function tests, he says.

鈥淩ace adjustment can be traced back to the idea that Black people are only healthy when enslaved鈥�

鈥�14%
Overestimation of kidney function using a race-based assessment鈥�

There are also to the most widely used eGFR equations. And, in the US, the Vaginal Birth After Cesarean (VBAC) calculator 鈥� a commonly used medical tool for second births 鈥� was .

Previously, the use of race and ethnicity adjustments in the VBAC calculator meant that women identified as African American or Hispanic were systematically assigned a lower chance of a successful VBAC than white women.

This may have , because a successful vaginal birth after caesarean is associated with reduced health risks than a repeat caesarean delivery. In the US, Black women have higher rates of caesarean deliveries than white women and are also .

Despite many of the organisations contacted by 麻豆传媒 not taking a stance on the issue, overall opinions on racial-adjustments appear to be shifting. 鈥淚t seems to be like a period of reckoning in medicine,鈥� says Nkinsi. 鈥淎 lot of it is being pushed back on, of course, because people are resistant to change, but I think we鈥檙e moving down a path where it鈥檚 no longer excusable to have these racist algorithms,鈥� she says.

Moffett agrees. 鈥淎 lot of this movement has been spearheaded by medical students, who are very distrustful of race as a concept in a way that many older clinicians are not,鈥� he says. 鈥淲hen they鈥檙e taught this in medical school, they just say, 鈥榳ell, that doesn鈥檛 make any sense鈥�, 鈥榯here鈥檚 no biological basis for this鈥�, 鈥榳hy are we using race in these models?鈥�.鈥�

Significant challenges remain, says Nkinsi, because racism is so deeply embedded in Western medicine. 鈥淢edicine is very hierarchical. It鈥檚 very much based on this kind of false meritocracy where for the longest time white men were running everything. You can鈥檛 question your superiors, medical students and younger physicians are supposed to just take things as they鈥檙e taught,鈥� she says. 鈥淲hat I鈥檓 trying to tell people is that it鈥檚 not just the algorithms, it鈥檚 the entire system and the way that we educate doctors that is creating this problem.鈥�

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