Types of Erythropoietin-Stimulating Agents and Mortality among Patients Undergoing Hemodialysis.

ABSTRACT

BACKGROUND: Despite the widespread use of erythropoietin-stimulating agents (ESAs) to treat anemia in patients undergoing hemodialysis, the relative mortality risks associated with use of different types of ESAs are unknown. METHODS: To compare the mortality risk associated with use of short-acting ESAs versus long-acting ESAs, we conducted a nationwide cohort study of 194,698 hemodialysis patients in Japan who received either a short-acting (epoetin α/ß or epoetin κ) or a long-acting (darbepoetin or epoetin ß pegol) ESA. Study outcomes were 2-year all-cause and cause-specific mortality. In addition to Cox proportional hazards models, we performed an instrumental variable analysis in which facility-level long-acting ESA prescription rates were taken as the instrumental variable. RESULTS: During the 2-year follow-up period, 31,557 deaths occurred. In a multivariable Cox model, long-acting ESA users had a 13% higher rate of deaths compared with short-acting ESA users, a significant difference (P<0.001). Similar results were obtained in other analyses. This difference in risk was pronounced among patients receiving high doses of ESA (for whom the adjusted 2-year number needed to harm for death was 30.8). Long-acting ESA use was associated with an increased rate of death from cardiovascular diseases, infection, and malignancies. In the instrumental variable analysis, long-acting ESA users remained at a significantly higher risk of death. Compared with anemic (hemoglobin 9.0-9.9 g/dl) short-acting ESA users, long-acting ESA users who achieved more optimal hemoglobin levels (10.0-10.9 g/dl) showed a higher mortality rate. CONCLUSIONS: Among patients undergoing hemodialysis, use of long-acting ESAs might be associated with a higher risk of death than use of short-acting ESAs.