Impact of “Black Race” Coefficient in Estimation of Glomerular Filtration Rate on Our Community and Medical Education

Abstract

Introduction: The use of race in estimation of glomerular filtration rate (eGFR) started a critical national conversation on numerous areas of medicine touched by racism; with a call for removal of race from calculation of eGFR. We scrutinized use of “Black race” coefficient in Modification of Diet in Renal Disease (MDRD) eGFR calculation and consequence of its use on our local community in SW Michigan. Methods: A cross-sectional analysis of de-identified electronic health record data from routine outpatient primary care visits, from January 1, 2019, to December 31, 2019, included variables such as age, race, gender, serum creatinine levels, and calculated eGFRs (if any), using χ2 tests for association and Wald-approximation 95% confidence interval. During the data collection period in 2019, both hospital systems and the outpatient clinic site were all using MDRD. Results: eGFR and associated CKD stage were calculated for 131,863 patients. χ2 tests found significant differences in rates of CKD stages 3, 4, and 5 between “Black” and “not Black.” And, the 95% confidence interval for the proportion of Black patients who would advance to the next stage of CKD upon ignoring “Black race” (using Wald-approximated confidence interval for binomial proportion) is between 41.1% and 43.0%. Discussion: The eGFR calculations which place Black patients in lower CKD stages initially may deprive them of important treatment and referral early in their disease course. Removal of the Black race coefficient allows for referral to a nephrologist, Medicare coverage, and the potential need for transplant and/or dialysis. Conclusion: Our analysis demonstrates the impact removal of “black race” coefficient from MDRD eGFR calculation could have on our community.