Self-identified race is a complex interplay of social identity, genetic ancestry, and socioeconomic status (1). In the setting of chronic kidney disease (CKD), classifying patients using race purely as a surrogate for genetic ancestry is problematic because social constructs and socioeconomic status play a large role in the development of CKD (2, 3). The use of race adjustment in the estimated glomerular filtration rate (eGFR) equation to determine kidney function has been questioned for several years because the race-based equation underestimates the prevalence and severity of CKD for patients self-identified as African American (4). Many have argued that the race-based eGFR increases the healthcare disparities between African Americans and non-African Americans (3). Given that African Americans have a higher risk of developing CKD and experience faster progression of kidney disease, early identification of kidney disease will allow earlier access to resources for kidney medical care (4). In September 2021, the National Kidney Foundation and American Society of Nephrology (NKF/ASN) Task Force on Reassessing the Inclusion of Race in Diagnosing Kidney Disease recommended the elimination of the race-based eGFR in all laboratories in the United States (5).
The recommendation made by the task force will lead to both clinical and social implications in the United States (Figure 1). A study by Diao et al. (6), recently published in the Journal of the American Medical Association, showed that the removal of the race modifier in creatinine-based eGFR calculations will increase the prevalence of CKD among patients who identify as African American, resulting in a higher proportion meeting eligibility for nephrology referral, kidney transplantation, coverage for kidney disease education, and coverage for medical nutrition therapy. On the other hand, the lower eGFR would exclude more African American patients from being eligible as a living kidney donor (6) or from receiving anti-cancer therapy (7). Therefore, the kidney medical community will need to monitor the impact of the non-race-based eGFR to ensure continued patient safety and health equity.
Would the new recommendation affect the reporting of kidney function in laboratories outside of the United States?
Other than the United States, only a few countries report a race-based eGFR. In France, the eGFR equation with and without the African American adjustment has been reported in laboratories. However, the use of the African American race adjustment for the eGFR equation in France has been debatable because the European Black populations are not comparable to the African American population in terms of factors such as body composition, diet, or muscle metabolism (8). Similarly, studies looking at the use of race eGFR in populations in the African nations and with African Europeans and African French have been noted to be imprecise (9). With the November 2021 publication in The New England Journal of Medicine (10) regarding the new creatinine- and cystatin C-based eGFR equation without race, laboratories in France have been gradually removing the race-adjusted eGFR.
In the United Kingdom, only a single eGFR is being reported. A UK-based study published in August 2021 in The Lancet Oncology (7) found that the race-based adjustment for people self-reported as Black has led to an overestimation of eGFR and potentially reduced access to care. In Japan, however, the laboratories report a single eGFR but one that has been validated for the Japanese population (11). Government hospitals in countries of middle and upper-middle income economies (e.g., India and Malaysia) report only serum creatinine levels without the eGFRs. According to the Global Kidney Health Atlas project, the availability of serum creatinine and eGFR in low-income countries is only 30% and 0%, respectively (12).
Thus, the recommendation by the NKF-ASN task force will not substantially impact the reporting of eGFR in laboratories around the globe. However, this pivotal move has shed light on a bigger conversation, i.e., recognizing problems that arise from health inequities and taking first steps toward reducing health disparities. Additional work focusing on the delivery of kidney care will be needed to truly achieve healthcare equity.
Acknowledgment
I would like to thank the following physicians for providing insights into the laboratory reporting of kidney function in their respective countries (in alphabetical order): Dr. Rachel Hung (United Kingdom), Dr. Stefanie Hung (Malaysia), Dr. Hassane Izzedine (France), Dr. Eunice Oon (Malaysia), Dr. Yugo Shibagaki (Japan), and Dr. Mayuri Trivedi (India).
References
- 1.↑
Bonham VL, et al. Examining how race, ethnicity, and ancestry data are used in biomedical research. JAMA 2018; 320:1533–1534. doi: 10.1001/jama.2018.13609
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Norton JM, et al. Social determinants of racial disparities in CKD. J Am Soc Nephrol 2016; 27:2576–2595. doi: 10.1681/ASN.2016010027
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Eneanya ND, et al. Reconsidering the consequences of using race to estimate kidney function. JAMA 2019; 322:113–114. doi: 10.1001/jama.2019.5774
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Diao JA, et al. Clinical implications of removing race from estimates of kidney function. JAMA 2021; 325:184–186. doi: 10.1001/jama.2020.22124
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Htay H, et al. Global access of patients with kidney disease to health technologies and medications: Findings from the Global Kidney Health Atlas project. Kidney Int Suppl (2011) 2018; 8:64–73. doi: 10.1016/j.kisu.2017.10.010
