National Estimates of CKD Prevalence and Potential Impact of Estimating Glomerular Filtration Rate Without Race

Abstract

Background: The implications of removing the adjustment for Black race in equations to eGFR on the prevalence of CKD and management strategies are incompletely understood.

Methods: We estimated changes in CKD prevalence and the potential effect on therapeutic drug prescriptions and prediction of kidney failure if race adjustment were removed from the CKD-EPI GFR estimating equation. We used cross-sectional and longitudinal data from adults aged ≥18 years in the National Health and Nutrition Examination Survey (NHANES) from 2015 to 2016, and the Veterans Affairs (VA) Health Care System in 2015. In the VA cohort, we assessed use of common medications that require dose adjustment on the basis of kidney function, and compared the prognostic accuracy of the Kidney Failure Risk Equation with versus without race adjustment of eGFR.

Results: The prevalence of CKD among Black adults increased from 5.2% to 10.6% in NHANES, and from 12.4% to 21.6% in the VA cohort after eliminating race adjustment. Among Black veterans, 41.0% of gabapentin users, 33.5% of ciprofloxacin users, 24.0% of metformin users, 6.9% of atenolol users, 6.6% of rosuvastatin users, and 5.8% of tramadol users were reclassified to a lower eGFR for which dose adjustment or discontinuation is recommended. Without race adjustment of eGFR, discrimination of the Kidney Failure Risk Equation among Black adults remained high and calibration was marginally improved overall, with better calibration at higher levels of predicted risk.

Conclusions: Removal of race adjustment from CKD-EPI eGFR would double the estimated prevalence of CKD among Black adults in the United States. Such a change is likely to affect a sizeable number of drug-dosing decisions. It may also improve the accuracy of kidney failure risk prediction among higher-risk Black adults.

Keywords: chronic kidney disease; glomerular filtration rate.

Graphical abstract

Figure 1.

Difference in prevalence of eGFR categories without versus with race adjustment in the NHANES 2015–2016 and Veterans’ Health Administration 2015 cohorts, by age group, sex, and diabetes mellitus status. A positive number indicates prevalence of eGFR category was higher without race adjustment, and a negative number indicates prevalence was lower without race adjustment.

Figure 2.

Number of Black adults with prescription in the following 90 days for common medications requiring dose adjustment for kidney function, and users potentially affected by change in eGFR. Dark-shaded bars represent veterans whose dose of medication would not be affected by removal of race adjustment from eGFR. Light-shaded bars represent the number of veterans whose eGFR without race adjustment crosses a dosing threshold. The figure above each bar represents the percentage of total medication users whose eGFR without race adjustment crosses a dosing threshold.

Figure 3.

Calibration plots for original KFRE using eGFR with race adjustment (solid black line), and KFRE using eGFR without race adjustment (dashed black line) among Black adults in the VA cohort.