Changes in hemoglobin level distribution in US dialysis patients from June 2006 to November 2008

Erythropoiesis-stimulating agents (ESAs) have had a positive effect on anemia treatment in dialysis patients. However, several events in recent years, including new clinical study results, ESA product label revisions, and coverage and reimbursement policy changes, have had an impact on ESA dosing patterns and consequently on hemoglobin (Hb) distribution characteristics in this patient population.

Retrospective observational study using patient-level data from approximately 87% of dialysis centers in the United States.

Dialysis patients who were receiving outpatient care at dialysis facilities during June 2006-November 2008 were included in this study.

Recent events affecting ESA treatment practice patterns in US dialysis patients.

Hb level distribution.

Mean Hb level decreased by 0.37 g/dL during the indicated period. Additionally, standard deviation (SD) of the Hb level distribution decreased by 0.14 g/dL and skewness increased by -0.10. Hb measurements in specific ranges changed as follows: >12 g/dL, decreased by 11.3 percentage points;10-12 g/dL, increased by 9.4 percentage points; and <10 g/dL, increased by 1.9 percentage points. The percentage of patients with Hb level >13 g/dL for > or =3 months decreased by 2.9 percentage points.

Potential bias in dialysis center selection and lack of information for patient characteristics.

Recent events affecting ESA use in dialysis patients have had the desired effect of increasing the proportion of Hb measurements within the US Food and Drug Administration recommended target range of 10-12 g/dL and decreasing the proportion of Hb measurements >12 g/dL. However, the proportion of Hb measurements <10 g/dL also has increased. Benefits of a decrease in Hb measurements in the >12 g/dL range need to be considered, together with risks of having low Hb levels.