In a study of 19,932 patients with 21,918 person-years of follow-up, researchers found no significant difference between patients treated with epoetin alfa (EPO) and darbepoetin alfa (DPO) with respect to overall and cardiovascular mortality, nonfatal myocardial infarction (MI), stroke, and a composite of cardiovascular death, nonfatal MI, and nonfatal stroke, investigators reported in the American Journal of Kidney Diseases (2015;66:106-113).
For the study, Wolfgang C. Winkelmayer, MD, MPH, ScD, of Baylor College of Medicine in Houston, and colleagues included patients initiating HD at independent and hospital-based U.S. facilities. Each facility switching from EPO to DPO was matched for location, profit status, and facility type with 1 EPO-using facility. Of the 508 facilities that switched from EPO to DPO, 492 were matched with a similar EPO-using facility. The study population included 10,467 patients (52.5%) receiving EPO and 9,465 (47.5%) receiving DPO.
The researchers acknowledged that their study was not randomized, so residual confounding remains a possibility. They pointed out, however, that they used an “intuitive quasi-experimental approach that mimicked a cluster-randomized trial in which facilities rather than individual patients are randomly assigned to receiving one treatment or another.”
Another limitation is related the fact that DPO is not widely used in the United States. It previously has been shown that large dialysis chains use EPO almost exclusively, so the researchers restricted their study to independent and hospital-based facilities, they explained. Whether their results generalize to other healthcare settings, such as chain dialysis facilities, or to other countries is unknown, they wrote.