A Standard Kidney Test Has a Racial Inequity Baked Into It

The pandemic has exposed racial disparities in health care that became obvious in COVID-19 case rates and patient treatment.

Another less apparent disparity? Kidney disease.

Before the pandemic, Black people disproportionately struggled with kidney issues. They also suffer more from high blood pressure and diabetes, which often leads to poor kidney function, says Jill Ginsberg, a doctor at North by Northeast Community Health Center in Portland's King neighborhood.

And COVID-19 isn't helping.

"COVID can, but doesn't always, affect kidney function. Severe disease can affect every organ system, and even people with less severe COVID can have minor damage to their kidneys, sometimes long lasting," Ginsberg says. "Black people suffer disproportionately from high blood pressure and diabetes, both of which can damage the kidneys."

In 2018, Black Oregonians who experienced kidney-related illness spent an average of eight days in the hospital, compared to white people who spent 6.4 days, according to the U.S. Renal Data System.

Not only does the Black population generally have worse kidney function, they tend to find out way later than everyone else—because of a race coefficient factor built into calculations of estimated glomerular filtration rate, a standard kidney filter test.

Black people are therefore at risk of learning they have decreased kidney function at a later stage than other racial groups. EGFR measures how well the kidneys filter and uses race as a variable, but lumps patients into one of two categories: African American or not African American. For Black people, the race-based formula multiplies their final score by a value above 1, making the result appear better than it actually is.

The University of Washington stopped using this race-based method a few years after UW students began questioning it.

Naomi Nkinsi, an M.D. student at UW's School of Medicine, fought for the change. "As we're learning more about COVID and its impact on kidneys, [the test] creates a very clear and obvious disparity on the types of health care they are getting based on the color of their skin," Nkinsi says.

In Portland, Legacy Health has acknowledged the disparity and is moving away from using the test. "While that had been the practice in the past, the lab team is working with providers to move away from race as a variable in estimating kidney function," Legacy spokesman Brian Terrett wrote in an email to WW.

Nkinsi says Black people should make sure they advocate for themselves when seeing a doctor.

"I want Black people to seek care when they need it, but then we also know we're less likely to be believed," Nkinsi says. "I think patients should feel more empowered to speak up when something is wrong, and be empowered to seek second opinions."

This reporting has been funded in part by a grant from the Jackson Foundation. See more Black and White in Oregon stories here.