Letters Section Editor: Robert M. Golub, MD, Senior Editor.
In Reply: Dr Regidor and colleagues suggest that their observational data1 are similar to clinical trial results. Figure 1 of their study1 shows the adjusted relative hazard ratio of death is approximately 1.5 when the hemoglobin level is 10.0 g/dL vs 1.0 when the hemoglobin level is 13.0 g/dL, while the largest dialysis anemia trial achieving those mean values found a 22% higher relative risk of death from a higher hemoglobin level.2 The study by Regidor et al1 also shows that the hazard ratio of death decreases from approximately 1.4 when the hemoglobin level is 10.0 g/dL to 11.0 g/dL to approximately 0.9 when the hemoglobin level is near 12.0 g/dL. However, actual adjusted mortality among US dialysis patients has not changed, although the mean hemoglobin level has steadily increased from 10 g/dL in 1993 to 12.0 g/dL in 2004.3
Coyne DW. Epoetin Dosing and Dialysis Facility Ownership—Reply. JAMA. 2007;298(8):861-863. doi:10.1001/jama.298.8.862-c