Background: Dialysis patients, receiving erythropoiesis stimulating agents, typically show signs of hemoglobin variability as a consequence of their dosing patterns, bleeding, infection, etc., which is commonly managed adjusting the dose regimen of the erythropoiesis stimulating agent. However, information on dosing strategies used in daily clinical practice and their outcomes in relation to hemoglobin variability is limited.
Objectives: To investigate clinical practice in Austria in relation with the management of hemoglobin variability, defined as a decrease of ³ 1 g/dL within 4 weeks from ³ 11 g/dL to £ 11 g/dL during maintenance therapy with darbepoetin alfa. The nature and incidence of clinical events related to the hemoglobin drop were also assessed.
Research design and methods: The MAINTAIN non-interventional study was conducted in hemodialysis patients, receiving darbepoetin alfa in accordance to the label approved in the European Union at that time. Patient data were documented retrospectively for the 3 months prior to the hemoglobin drop. Data for the 6 months post hemoglobin drop were collected retrospectively or prospectively, depending on the time of patient inclusion respective to the Hb drop.
Results: A hundred thirty six of 154 patients fulfilled all inclusion/exclusion criteria and had prospective documentation of 6 months. The main causes for the hemoglobin drop included surgical and medical procedures (36.1 %), and infections or infestations (24.4 %). The median treatment period was 273 days. The mean hemoglobin drop was - 1.74 g/dL (95 % confidence interval (CI): - 1.60 to - 1.87). Consequently, 81 % of the patients had their dose of darbepoetin alfa increased within a median Kaplan-Meier time to dose increase of 12.5 days (95 % CI: 6-22). The geometric mean weekly darbepoetin alfa dose increased by a factor of 1.1 from 29.1 mg (95 % CI: 24.6-34.4) in the 3 months before hemoglobin drop to 32.4 (95 % CI: 27.2-38.6) in months 4-6 post hemoglobin drop. Three patients had red blood cell transfusions before hemoglobin drop and nine patients after hemoglobin drop. The mean hemoglobin increase was 0.43 g/dL (95 % CI: 0.24-0.62) from immediately prior to 2 weeks after dose increase. The median Kaplan-Meier time to achieve a hemoglobin ³ 11 g/dL after hemoglobin drop was 36 days (95 % CI: 32-45). Frequent darbepoetin alfa dose adjustments were necessary to sustain maintenance levels. No drug-related adverse events were reported.
Conclusions: This observational study describes physicians' reactions to a drop in hemoglobin in clinical practice. Using darbepoetin alfa, the drop was generally compensated without leading to overcorrection.