UW Medical Students Force Change to Key Kidney Measure to End Disparity

October 16, 2020

Prompted by students, the medical school overturned a longstanding diagnostic protocol that was not well-founded in evidence.

For years, tests for renal health have graded Black patients on a different scale from everyone else—with a result that likely caused many to see greater renal decline before they became eligible for kidney care or a transplant.

At the University of Washington (UW) Medicine, that changed on June 1, when medical students won a 2-year fight for all tests to be evaluated the same way.

The shift represents a huge shift that will launch broader conversations about assumptions that medicine has made about Black patients; these assumptions have found their way into formulas and algorithms, even if they are not based on facts. And these assumptions can lead to disparities in health outcomes—for example, it’s documented that Black individuals are 4 times more likely than Whites to have kidney failure.

Other false narratives in medicine involve the idea that Black patients have thicker skin and don’t experience as much pain, which can lead to Black patients not being prescribed appropriate pain medication or being misdiagnosed when they have appendicitis. Another myth involved the idea that Black individuals had thicker skulls.

The current change involves calculation of estimated glomerular filtration rate (eGFR) when time serum creatinine is measured. Almost every lab has used the Modification of Diet in Renal Disease (MDRD) equation to calculate eGFR to when determining serum creatinine levels. Creatinine is a by-product of muscle breakdown, so elevated levels suggest that the renal system is stressed and having trouble filtering it out in the blood.

When the first study was conducted to calculate eGFR, Black patients had higher scores than White patients, on average. But rather than ask why they may be more likely to experience end-stage kidney disease, the investigators assumed the levels were normal—the Black participants just had more muscle mass, and thus higher creatinine levels. So, for years, eGFR scores were adjusted to account for this “difference.”

Even a later study that produced a more accurate equation—the chronic kidney disease epidemiology collaboration, or CKD-EPI—retained the adjustment for Black patients. But this correction has had serious consequences. If Black patients have to overcome the effects of a correction factor before they are considered in end-stage renal disease (ESRD), they do not receive dialysis when they should and they are sicker when they get on a registry for kidney donation.

Two years ago, a group of UW medical students who were being taught how to calculate the MDRD instead asked why it was being used in the first place.

“So how did we make this change?” asked Naomi Nkinsi. “We did it by not letting the issue go and continuing to push discussions in class about the use of this equation.”

That involved faculty meetings, reviewing research articles, and pursuing small group discussions, according to information from the medical school.

“This is a momentous change where UW Medicine is leading the way,” said Rajnish Mehrotra, MD, MS, interim head of the Division of Nephrology, said in a statement.

Nkinsi said the decision on the diagnostic protocol shows the need to question the appropriateness of racial attributions in medicine and shows that the next generation of physicians must be trained differently.

“The historic decision by UW Medicine to no longer use race as a variable to estimate kidney function is significant in multiple ways, she said. First, it shows that our medical system refuses to participate in the perpetuation of racism in medical practice, and has taken a stand to end the false narrative that Black bodies are inherently inferior to White bodies.

Secondly, the move signals that medical students have a powerful voice that is already shaping the future of academic medicine. This was an effort led by medical students, especially Black students, who have advocated to remove racism in the medical school curriculum and in clinical practice for many years.

This decision shows that students can have a profound impact. It is because students persisted in asking questions and having sometimes difficult conversations that an institution, and the field of medicine more broadly, changed.”