The original CKD-EPI and MDRD studies showed an association between African-American race with higher measured GFR at the same blood creatinine concentration. However, there have been concerns raised about the application of the race multiplier to all African-American patients. First, there is no clear biological explanation for the association, the identification of Black race was unclear in some of the cohorts used in these studies, and there is vast genetic and ancestral heterogeneity among those who self-identify as black. The use of the race multiplier also ignores the fact that race is a social, not biological construct.
We found that with the removal of the race multiplier, up to one in every three African-American patients would be reclassified as having a more severe stage of CKD, with one-quarter of African-American patients going from stage 3 to stage 4. We also found that with the removal of the race multiplier, 64 patients would have had an eGFR <20, the threshold for referral for kidney transplant, and none of these patients were referred, evaluated or waitlisted for transplant. This is in contrast, to those African-American patients with an eGFR <20 with the race multiplier applied, who had a higher odds of being referred, evaluated or waitlisted for transplant compared to other racial groups (Odds ratio of 2.28, compared to White cohort).(more…)