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 51¶ŻÂț 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 â 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.
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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.
âThese are extremely difficult to measure, quantify and âcorrect forâ in interpreting test results,â said Heaton in a written statement to 51¶ŻÂț. âThe fact remains, that a very substantial amount of variability in the test performance of normal adults can be âexplainedâ (accounted for) by the demographic variables of age, education, sex, and race/ethnicity (together), so our best available norms âcorrectâ for these characteristics.â
Crude proxy
Possin disagrees with using race in this way. âRace is a crude proxy for lifelong social experience,â she says. âGenetic 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,â she says. It also perpetuates the false idea that Black people are less intelligent than white people, she says. âThatâs a big problem.â
â1990s
Decade the practice of race-norming was establishedâ
Race-norming could even be exacerbating health issues experienced by people as a result of social factors. âWeâre using race as a proxy for other things, instead of measuring those things directly,â 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 51¶ŻÂț.
âCorrecting for lifelong social experience with something crude, like race, is not precise medicineâ
âThe INS does not have guidelines nor take a stance [on] race norming,â said the INS. âWe are a global organization and focus on topics that are applicable around the world.â
The APA said: âThe APA has no official position⊠on race-based norming and cognitive testing.â
Race adjustments arenât 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 âa correction factor to GFR values⊠for people of African-Caribbean or African family originâ.
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 .
âThere is no evidence that race is related to muscle mass,â 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. âFrom this they said, âOh, well if they have a higher creatinine, it must mean that Black people have a higher muscle massâ,â she says.
But that study included just 1628 participants, only 197 of whom identified as African American. âItâs based on this one observation that they found out of a very, very small population,â 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. âSo 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.â
Not just faulty, but potentially harmful. A preliminary study in the UK led by Rouvick Gama and Kate Bramham at Kingâs 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. âIt could lead to delay in diagnosis of chronic kidney disease,â he says, and thus delays in treatment â something borne out by UK health statistics.
âIf youâre of Black ethnicity, youâre three to fivefold more likely to end up with end-stage kidney disease,â says Bramham. âAlmost certainly weâre not recognising it enough.â 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: âKDIGO is not in a position to comment on the rationale used to determine the adjustment in eGFR calculations.â
NICE told 51¶ŻÂț 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 âfor adults of African-Caribbean or African family originâ. The draft guidance suggested that future research should explore the use of âfactors other than ethnicityâ as biological markers.
In the US, the National Kidney Foundation and the American Society of Nephrology established a task force in 2020 to âreassess the inclusion of race in the estimation of GFRâ. 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.
âMedicine dependent on these equations is being recognised as built on faulty scienceâ
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. âWeâre assuming that their lung function should be worse and using that as a way to approach the diagnosis,â 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 . âEverything weâve learned about race in the last 50 years has invalidated this,â says Moffett.
Joint European Respiratory Society and American Thoracic Society (ATS) guidelines recommend the use of . âIngrained in lung function interpretation is the long-standing assumption that the observed differences across racial and ethnic populations is biologically based,â the ATS told 51¶ŻÂț.
âThere 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,â said the ATS, adding that it is âcommitted to leading action to address racism in medicine and eliminate the misuse of race and ethnicity in clinical decision makingâ and that it has âconvened a workshop to critically evaluate current guidelinesâ.
Changing times
Moffett thinks race-norming adjustments should be stopped. He and his colleagues are currently developing a ârace-free equationâ for interpreting lung function tests, he says.
âRace adjustment can be traced back to the idea that Black people are only healthy when enslavedâ
â14%
Overestimation of kidney function using a race-based assessmentâ
There are also to the most widely used eGFR equations. And, in the US, the Vaginal Birth After Cesarean (VBAC) calculator â a commonly used medical tool for second births â 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 51¶ŻÂț not taking a stance on the issue, overall opinions on racial-adjustments appear to be shifting. âIt seems to be like a period of reckoning in medicine,â says Nkinsi. âA lot of it is being pushed back on, of course, because people are resistant to change, but I think weâre moving down a path where itâs no longer excusable to have these racist algorithms,â she says.
Moffett agrees. âA 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,â he says. âWhen theyâre taught this in medical school, they just say, âwell, that doesnât make any senseâ, âthereâs no biological basis for thisâ, âwhy are we using race in these models?â.â
Significant challenges remain, says Nkinsi, because racism is so deeply embedded in Western medicine. âMedicine is very hierarchical. Itâs very much based on this kind of false meritocracy where for the longest time white men were running everything. You canât question your superiors, medical students and younger physicians are supposed to just take things as theyâre taught,â she says. âWhat Iâm trying to tell people is that itâs not just the algorithms, itâs the entire system and the way that we educate doctors that is creating this problem.â
False beliefs and racial biases
The use of race-based adjustments in routine medical tests (see main story) isnât the only thing contributing to racial-ethnic health disparities. False beliefs about biological differences between racial groups may also contribute.
For example, harmful beliefs, such as the false notion that Black people feel less pain than white people, may result in physicians and .
A and residents found that about half of them endorsed at least one of a list of incorrect statements about biological differences between Black and white people. These included statements such as âBlack peopleâs nerve-endings are less sensitive than White peopleâs nerve-endingsâ and âBlack peopleâs skin has more collagen (i.e. itâs thicker) than White peopleâsâ. The study also found that these false beliefs predicted racial biases in the assessment of pain in fictional patients and in subsequent treatment recommendation.
Racial biases in medicine are also embedded in technology. In 2019, a study revealed that Black people in the US may have been missing out on healthcare because of racial bias in a widely used algorithm. The study suggested that the proportion of Black people referred for extra care would more than double if the bias were removed.
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