Impact of Race-Free Glomerular Filtration Rate Estimations on CKD Prevalence in the US Military Health System: A Retrospective Cohort Study

Rationale & ObjectiveThe 2021 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation removes Black race as a factor in calculating estimated glomerular filtration rate (eGFR). We assessed its impact on CKD prevalence in the demographically-diverse US Military Health System (MHS).Study DesignRetrospective calculation of eGFR from serum creatinine measured over 2016–2019 using both the 2009 and 2021 CKD-EPI equations.Setting & PopulationMulticenter health care network with data from 1,502,607 adults in the complete case analysis and from 1,970,433 adults in imputed race analysis.PredictorsSerum creatinine, age, sex, and race.OutcomeCKD stages 3–5, defined as the last eGFR persistently < 60 mL/min/1.73m2 for ≥ 90 days.Analytical ApproachStudent's t-test and Kruskal-Wallis test for continuous variables and Χ2 for categorical data.ResultsThe population in the complete case analysis had a median age of 40 years and was 18.8% Black race and 35.4% female. With the 2021 equation, the number of Black adults with CKD stages 3–5 increased 58.1% from 4,147 to 6,556, a change in crude prevalence from 1.47% to 2.32%. The number of non-Black adults with CKD stages 3–5 decreased 30.4% from 27,596 to 19,213, a crude prevalence change from 2.26% to 1.58%. Similar results were seen with race imputation. Cumulatively, among adults with CKD stages 3–5 by at least one equation, 45.8% of Black adults were reclassified to more advanced stages of CKD and 44.0% of non-Black adults were reclassified to less severe stages across eGFR thresholds that could change clinical management.LimitationsPotential underestimation of CKD in individuals with only one measurement.ConclusionsAdoption of the 2021 CKD-EPI equation in the MHS reclassifies many Black adults into new CKD stages 3–5 or into more advanced CKD stages, with the opposite effect on non-Black adults. This may have an impact on CKD treatment and outcomes in ways that are yet unknown.