Stevens L.A., Claybon M.A., Schmid C.H., Chen J., Horio M., Imai E., Nelson R.G., Van Deventer M., Wang H.-Y., Zuo L., Zhang Y., Levey A.S.
Tufts Medical Center, Division of Nephrology, Box 391, 800 Washington Street, Boston, MA 02111, United States; Tulane University School of Medicine, New Orleans, LA, United States; Osaka University Graduate School of Medicine, Osaka, Japan; National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Phoenix, AZ, United States; Department of Chemical Pathology, NHLS, University of the Witwatersrand, Johannesburg, South Africa; Peking University First Hospital, Beijing, China
Stevens, L.A., Tufts Medical Center, Division of Nephrology, Box 391, 800 Washington Street, Boston, MA 02111, United States; Claybon, M.A., Tufts Medical Center, Division of Nephrology, Box 391, 800 Washington Street, Boston, MA 02111, United States; Schmid, C.H., Tufts Medical Center, Division of Nephrology, Box 391, 800 Washington Street, Boston, MA 02111, United States; Chen, J., Tulane University School of Medicine, New Orleans, LA, United States; Horio, M., Osaka University Graduate School of Medicine, Osaka, Japan; Imai, E., Osaka University Graduate School of Medicine, Osaka, Japan; Nelson, R.G., National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Phoenix, AZ, United States; Van Deventer, M., Department of Chemical Pathology, NHLS, University of the Witwatersrand, Johannesburg, South Africa; Wang, H.-Y., Peking University First Hospital, Beijing, China; Zuo, L., Peking University First Hospital, Beijing, China; Zhang, Y., Tufts Medical Center, Division of Nephrology, Box 391, 800 Washington Street, Boston, MA 02111, United States; Levey, A.S., Tufts Medical Center, Division of Nephrology, Box 391, 800 Washington Street, Boston, MA 02111, United States
An equation from the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) provides more accurate estimates of the glomerular filtration rate (eGFR) than that from the modification of diet in renal disease (MDRD) Study, although both include a two-level variable for race (Black and White and other). Since creatinine generation differs among ethnic groups, it is possible that a multilevel ethnic variable would allow more accurate estimates across all groups. To evaluate this, we developed an equation to calculate eGFR that includes a four-level race variable (Black, Asian, Native American and Hispanic, and White and other) using a database of 8254 patients pooled from 10 studies. This equation was then validated in 4014 patients using 17 additional studies from the United States and Europe (validation database), and in 1022 patients from China (675), Japan (248), and South Africa (99). Coefficients for the Black, Asian, and Native American and Hispanic groups resulted in 15, 5, and 1% higher levels of eGFR, respectively, compared with the White and other group. In the validation database, the two-level race equation had minimal bias in Black, Native American and Hispanic, and White and other cohorts. The four-level ethnicity equation significantly improved bias in Asians of the validation data set and in Chinese. Both equations had a large bias in Japanese and South African patients. Thus, heterogeneity in performance among the ethnic and geographic groups precludes use of the four-level race equation. The CKD-EPI two-level race equation can be used in the United States and Europe across a wide range of ethnicity. © 2011 International Society of Nephrology.