Among long-term hemodialysis patients, doses are 12.6% higher in blacks than in whites.
Black patients on long-term hemodialysis receive greater doses of erythropoietin (EPO) than their white counterparts even though both races achieve similar hemoglobin levels, data show.
The finding comes from a study of 44,721 Medicare-insured long-term hemodialysis patients (20,931 black [43%] and 23,790 [57%) white) treated by Fresenius Medical Care in Charlotte, N.C.. The researchers showed that, overall, black patients were administered 12.6% greater EPO doses than white patients, according to a report in the American Journal of Kidney Diseases (2008; published online ahead of print).
This racial gap decreased to 7% (a nearly 45% decrease) after adjusting for prior hospitalization, baseline hemoglobin level, gender, age, the presence or absence of diabetes mellitus, dialysis vintage, catheter use, body surface area, and postdialysis weight. The difference between the races remained statistically significant, however.
For the study cohort as a whole, the researchers found that prior hospitalization, catheter use, and younger age were associated with increased EPO dose.
The researchers, led by Eduardo Lacson Jr, MD, MPH, vice president of Clinical Science, Epidemiology, and Research at Fresenius, also found that age had a strong and significant effect on the association between race and dose. Adjusting for age decreased the difference between blacks and whites by 33.9%; researchers said this was because the black patients were younger. Blacks had a mean age of 59.4 years compared with 65.7 years for whites.
In addition, the investigators observed that race differences in EPO dose varied by age. The differences were most pronounced among patients younger than 45 years and those aged 65 years and older, with blacks receiving an EPO dose approximately 16%-17% greater than that of whites. After controlling for case-mix (age, gender, race, presence or absence of diabetes, and dialysis vintage) and laboratory variables, this difference decreased to 6% in the younger-than-45 group and 7.5% in the 65 and older group.
A greater proportion of black patients (6% of the black patients in the study) were in the 95th percentile of EPO dose (greater than 60,000 units/week) than white patients (4% of white patients in the study).