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Performance of creatinine-based equations to estimate glomerular filtration rate in White and Black populations in Europe, Brazil, and Africa.

BACKGROUND
A new Chronic Kidney Disease Epidemiology equation without race variable has been recently proposed (CKD-EPIAS). This equation has neither been validated outside USA nor compared to the new European Kidney Function Consortium (EKFC) and Lund-Malmö Revised (LMREV) equations, developed in European cohorts.


METHODS
Standardized creatinine and measured glomerular filtration rate (GFR) from the European EKFC cohorts (n = 13 856 including 6031 individuals in the external validation cohort), from France, (n = 4429, including 964 Black Europeans), from Brazil (n = 100), and from Africa (n = 508) were used to test the performances of the equations. A matched analysis between White Europeans and Black Africans or Black Europeans was performed.


RESULTS
In White Europeans (n = 9496), both the EKFC and LMREV equations outperformed CKD-EPIAS (bias of -0.6 and -3.2, respectively versus 5.0 mL/min/1.73m², and accuracy within 30% of 86.9 and 87.4, respectively versus 80.9%). In Black Europeans and Black Africans, the best performance was observed with the EKFC equation using a specific Q-value ( = concentration of serum creatinine in healthy males and females). These results were confirmed in matched analyses, which showed that serum creatinine concentrations were different in White Europeans, Black Europeans, and Black Africans for the same measured GFR, age, sex and body mass index. Creatinine differences were more relevant in males.


CONCLUSION
In a European and African cohort, the performances of CKD-EPIAS remain suboptimal. The EKFC equation, using usual or dedicated, population-specific Q-values presents the best performance in the whole age range in the European and African populations included in this study.