The AACC, in collaboration with the National Kidney Foundation (NKF), has released guidance to reduce racial and gender disparities in the care of patients with chronic kidney disease (CKD). The document gives members of the healthcare team actionable, evidence-based tools to improve equity in kidney health, including recommendations for using an updated algorithm that does not disproportionately affect any one group of individuals

In the United States, 37 million adults—or 1 in 7 people—are affected by kidney disease. The AACC/NKF guidance builds on the progress of a joint task force of the NKF and the American Society of Nephrology, which in 2021 recommended new equations for determining estimated glomerular filtration rate (eGFR), a gauge of kidney function. Previously, eGFR was calculated using a variable for Black race because study participants who described themselves as African American were found to have higher blood levels of creatinine, a marker for kidney disease, than other groups. The new equations don’t include this variable.

As the guidance explains, factoring race into clinical algorithms can lead to unintentional biases because race and ethnicity are social, rather than biological, constructs. While genetic variants may influence kidney disease risk in some Black individuals, definitions of race vary widely and have changed over time. Moreover, Black and Hispanic people are more likely to experience lower quality of care and poorer outcomes due to inequitable access to health and social resources.

The guidance includes recommendations for integrating race-free equations into laboratory information systems and communicating the change to providers. It also calls on clinical laboratory professionals to help reduce racial and ethnic disparities in chronic kidney disease by participating in multidisciplinary teams to improve disease detection, particularly in high-risk populations, and working to standardize biomarker testing and reporting.

“Race and ethnicity are imprecise, nebulously defined systems of classification as they pertain to genetic ancestry, physiological characteristics, and socioeconomic status, and therefore should not be used to classify individuals into distinct biological categories,” say the guidance lead authors Christina C. Pierre, PhD, DABCC, FAACC, and Mark A. Marzinke, PhD.

The AACC/NKF document also recommends incorporating a marker called cystatin C into eGFR equations in addition to creatinine, because equations that use both markers show superior performance over those that use one or the other.

In addition, the guidance provides recommendations to improve the management of chronic kidney disease in gender-diverse patients. Because biological sex impacts creatinine levels, the eGFR equations include a variable to account for sex. But applying a binary sex variable is problematic for transgender people because gender-affirming hormones can cause changes in muscle mass and fat distribution that affect creatinine. For gender-diverse patients, the authors of the guidance suggest calculating eGFR using male and female variables, and taking an inclusive, holistic approach to disease management.