Two leading medical associations recently recommended that doctors stop using race as a variable to determine how effective their kidneys are at removing waste from their bodies. This practice has been in place for decades. Before, doctors would examine the level of a chemical in the blood and then multiply it by an approximate 1.15 factor if the patient was Black. The use of race to determine kidney function can lead to delays in dialysis and kidney transplants for patients of color, particularly Black patients.
The recent decision was made by 14 experts who spent nearly a year reviewing dozens of options, interviewing patients and weighing the effects of keeping race out of the equation. The final recommendation ensures that the corrected kidney equation is accurate for all, regardless of race.
Other risk equations that incorporate race are still being used. These include ones that were used to deny ex-NFL players their payouts in a settlement for concussions, ones that could underdiagnose breast cancer in Black women and ones that miscalculated the lung function in Black and Asian patients. It will take more than one task force to end the use of race-based multipliers for these and many other calculators. Researchers will need to believe and act upon the fact that race is not biology. The biomedical research enterprise must also establish clearer standards for how these calculators should be used. It's only a matter time before another tool, which wrongly uses race to make medical decisions about patients' bodies, is introduced into clinical care.
Over the past four decades, doctors have relied upon risk calculators to help them make quick decisions in the face uncertainty. Graham Walker, a California-based ER physician, said that doctors tend to stick to the versions they were first exposed to during medical school or their residency. The kidney function equation was recently updated. Many clinicians still use an older version of the equation that does not include the correction. This version, which was first created in 1973, is still the most used on MDcalc. Walker and Joseph Habboushe developed MDcalc as a website and mobile app to collect risk calculators and make them accessible to clinicians. Although they don't track users, statistics and a survey from 2018 suggest that around 68 percent US doctors use MDCalc at the very least once a week.
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It is not surprising, given the fact that scientists used race to differentiate between people before modern medicine, that race was a component of many risk calculators.
Race was used in many equations, including the kidney function equation. It is used to represent differences in measurements of biomarkers that were observed among study participants. These participants were typically either black or white. These differences can be explained by biological factors. They are not due to race, but health disparities. These might be statistical blips if there weren't enough Black participants in a study.
While kidney function equations for the US included a multiplier to account for Blackness, calculators from other parts of the globe were able to use Chinese or Japanese coefficients. Non-Black Americans of color in the US have seen their doctors average the Black and non Black values to estimate kidney function. Or, they simply default to the normalusually white estimates.
These types of calculators are often developed by scientists who rely on long-running CDC databases that include a column with demographic details beside biological statistics like weight and disease stage. Multipliers for race and ethnicity are a useful proxy for the unknown reasons behind these differences. It is difficult to calculate the collective impact of this practice. Without MDcalc numbers, it is impossible to determine how many times a risk calculator has been used or how each doctor uses the results to guide patient care. It is clear that today's risk equations still consider race.
Risk calculators? They bypass all the checks and safeguards that are required.
There is another way. Researchers created a new risk calculator called the VACO index in November 2020 to predict death rates one month after positive Covid-19 tests. The Veterans Affairs health system closely tracks not only a person's race, but also any preexisting conditions that could affect the course and outcome of a Covid infection. The developers added variables to represent an individual's age, gender, chronic conditions, such as hypertension. Race didn't matter. A race-free equation was equally effective for all participants.
Researchers suggest that the VA system has fewer barriers for patients to access care. This could explain why the accuracy of the equations does not improve because of race. Health disparities are often due to systemic barriers and unqual access to healthcare. The apparent race-based disparity in death risk was reduced by removing barriers. The medical history of the developers could also be a possibility, as it could help explain the biology of the disease and not rely on race. Habboushe states that both theories about the VACO score suggest that Covid might seem worse in underserved communities because we don't know enough about chronic conditions or other social determinants to health. It is not a matter of race.