The purpose of this study was to assess the sociodemographic factors that influenced the use of recombinant erthyropoietin (rHuEPO) during the first year after the drug was given FDA approval, when clinical guidelines for its use were less well established. Recombinant erthyropoietin is a high cost new medication for the treatment of dialysis-dependent end stage renal disease (ESRD) patients.

Data for this study were derived from Medicare (ESRD PMMIS) claims data; all Medicare patients enrolled in the ESRD program at any time from July 1,1989 through June 30, 1990 who were eligible to receive rHuEPO were included.

Over 50% of all Medicare-entitled dialysis patients were receiving rHuEPO by the end of the first fiscal year following FDA approval. The analyses, which adjusted for age, sex, duration of ESRD, cause of ESRD, dialysis setting, for-profit/not-for-profit status of the treating facility, and network (location), showed a strong association between rHuEPO use and race, with an odds ratio (OR) for blacks versus whites of 0.88 (95% confidence interval =0.86 to 0.91). Only 56% of the black patients undergoing hemodialysis were treated with rHuEPO, compared with 62% of the white patients. These differences persisted even after controlling for medical characteristics. That is, there were lower, adjusted rHuEPO treatment rates in blacks compared with whites, even though the average first-month hematocrit of black patients who received rHuEPO was slightly lower than that of their white counterparts (which might be considered a clinical indicator suggesting a greater level of appropriateness for use of this treatment among blacks).

The authors note that income/wealth differences, uncontrolled in this analysis, might be at least partially responsible for the findings since this might affect patients' ability to afford the 20% co-payment.

It should be noted that this study may not reflect use of rHuEPO in subsequent years. Financial policies with regard to this treatment, while established with the intent to cover costs for delivering the treatment in average doses established during the early clinical trials, actually set up a financial incentive to use rHuEPO in a particular manner. It was financially advantageous to use rHuEPO as frequently as possible, but to administer it in small doses. The more frequent use of rHuEPO among patients receiving care in for-profit versus not-for-profit facilities could reflect the possibility that for-profit facilities responded to this financial incentive. The authors note that this possibility and the influence of the rHuEPO association with sociodemographic characteristics should be further explored.