CKD anemia content reviewed November 6, 2026 against KDIGO 2026. See the population-specific KDIGO 2026 rules.
- Choose the ESA and enter native dose, frequency, positive weight, and Hb in g/dL.
- Read the longitudinal ERI or native CERA exposure. Darbepoetin ×200 is approximate; CERA is not converted using that ratio.
- Review the clinical response. No ERI cutoff alone establishes hyporesponsiveness or an appropriate dose.
When to use
Investigate iron deficiency or iron-restricted erythropoiesis, inflammation/infection, bleeding, hemolysis, nutritional deficiency, hyperparathyroidism, inadequate dialysis, adherence, and marrow disease before escalating an erythropoiesis-stimulating agent (ESA). A sudden Hb decline with severe reticulocytopenia raises concern for pure red cell aplasia and requires specialist evaluation.
The ESA resistance index (ERI) is weekly epoetin dose ÷ weight ÷ Hb in g/dL. It is a longitudinal exposure/response measure, not a stand-alone diagnosis or instruction to maintain a dose. KDIGO 2026 Table 10 summarizes heterogeneous definitions; ERI 10 is not a universal KDIGO cutoff. Darbepoetin-to-epoetin conversions are approximate and dose-dependent; do not apply a fixed 200-IU/µg factor to CERA as a validated conversion.
Source: KDIGO 2026 Anemia in CKD, recommendations 2.1–2.4 and 3.2.1–3.3.1; practice points 2.2–2.8 and 3.4.1.2–3.4.3.5. Reviewed November 6, 2026. Apply clinical judgment and the locally approved product label.
Interpretation and limitations
Investigate iron deficiency or iron-restricted erythropoiesis, inflammation/infection, bleeding, hemolysis, nutritional deficiency, hyperparathyroidism, inadequate dialysis, adherence, and marrow disease before escalating an erythropoiesis-stimulating agent (ESA). A sudden Hb decline with severe reticulocytopenia raises concern for pure red cell aplasia and requires specialist evaluation.
The ESA resistance index (ERI) is weekly epoetin dose ÷ weight ÷ Hb in g/dL. It is a longitudinal exposure/response measure, not a stand-alone diagnosis or instruction to maintain a dose. KDIGO 2026 Table 10 summarizes heterogeneous definitions; ERI 10 is not a universal KDIGO cutoff. Darbepoetin-to-epoetin conversions are approximate and dose-dependent; do not apply a fixed 200-IU/µg factor to CERA as a validated conversion.
Source: KDIGO 2026 Anemia in CKD, recommendations 2.1–2.4 and 3.2.1–3.3.1; practice points 2.2–2.8 and 3.4.1.2–3.4.3.5. Reviewed November 6, 2026. Apply clinical judgment and the locally approved product label.
Why Use It
Investigate iron deficiency or iron-restricted erythropoiesis, inflammation/infection, bleeding, hemolysis, nutritional deficiency, hyperparathyroidism, inadequate dialysis, adherence, and marrow disease before escalating an erythropoiesis-stimulating agent (ESA). A sudden Hb decline with severe reticulocytopenia raises concern for pure red cell aplasia and requires specialist evaluation.
The ESA resistance index (ERI) is weekly epoetin dose ÷ weight ÷ Hb in g/dL. It is a longitudinal exposure/response measure, not a stand-alone diagnosis or instruction to maintain a dose. KDIGO 2026 Table 10 summarizes heterogeneous definitions; ERI 10 is not a universal KDIGO cutoff. Darbepoetin-to-epoetin conversions are approximate and dose-dependent; do not apply a fixed 200-IU/µg factor to CERA as a validated conversion.
ESA Resistance Index (ERI) Calculator
Select the ESA type, enter the dose per administration and frequency, patient weight, and current hemoglobin. Results update automatically.
Investigate iron deficiency or iron-restricted erythropoiesis, inflammation/infection, bleeding, hemolysis, nutritional deficiency, hyperparathyroidism, inadequate dialysis, adherence, and marrow disease before escalating an erythropoiesis-stimulating agent (ESA). A sudden Hb decline with severe reticulocytopenia raises concern for pure red cell aplasia and requires specialist evaluation.
The ESA resistance index (ERI) is weekly epoetin dose ÷ weight ÷ Hb in g/dL. It is a longitudinal exposure/response measure, not a stand-alone diagnosis or instruction to maintain a dose. KDIGO 2026 Table 10 summarizes heterogeneous definitions; ERI 10 is not a universal KDIGO cutoff. Darbepoetin-to-epoetin conversions are approximate and dose-dependent; do not apply a fixed 200-IU/µg factor to CERA as a validated conversion.
Next steps
Investigate iron deficiency or iron-restricted erythropoiesis, inflammation/infection, bleeding, hemolysis, nutritional deficiency, hyperparathyroidism, inadequate dialysis, adherence, and marrow disease before escalating an erythropoiesis-stimulating agent (ESA). A sudden Hb decline with severe reticulocytopenia raises concern for pure red cell aplasia and requires specialist evaluation.
The ESA resistance index (ERI) is weekly epoetin dose ÷ weight ÷ Hb in g/dL. It is a longitudinal exposure/response measure, not a stand-alone diagnosis or instruction to maintain a dose. KDIGO 2026 Table 10 summarizes heterogeneous definitions; ERI 10 is not a universal KDIGO cutoff. Darbepoetin-to-epoetin conversions are approximate and dose-dependent; do not apply a fixed 200-IU/µg factor to CERA as a validated conversion.
Source: KDIGO 2026 Anemia in CKD, recommendations 2.1–2.4 and 3.2.1–3.3.1; practice points 2.2–2.8 and 3.4.1.2–3.4.3.5. Reviewed November 6, 2026. Apply clinical judgment and the locally approved product label.
Evidence and clinical rules
Investigate iron deficiency or iron-restricted erythropoiesis, inflammation/infection, bleeding, hemolysis, nutritional deficiency, hyperparathyroidism, inadequate dialysis, adherence, and marrow disease before escalating an erythropoiesis-stimulating agent (ESA). A sudden Hb decline with severe reticulocytopenia raises concern for pure red cell aplasia and requires specialist evaluation.
The ESA resistance index (ERI) is weekly epoetin dose ÷ weight ÷ Hb in g/dL. It is a longitudinal exposure/response measure, not a stand-alone diagnosis or instruction to maintain a dose. KDIGO 2026 Table 10 summarizes heterogeneous definitions; ERI 10 is not a universal KDIGO cutoff. Darbepoetin-to-epoetin conversions are approximate and dose-dependent; do not apply a fixed 200-IU/µg factor to CERA as a validated conversion.
Source: KDIGO 2026 Anemia in CKD, recommendations 2.1–2.4 and 3.2.1–3.3.1; practice points 2.2–2.8 and 3.4.1.2–3.4.3.5. Reviewed November 6, 2026. Apply clinical judgment and the locally approved product label.
