EPO and myelodysplastic syndrome with single lineage dysplasia: A meta‐analysis of 30 studies published between 1990 and 2006, which included 1314 MDS patients, identified the following as being predictive of response to ESA treatment: low transfusion dependence; a morphological diagnosis of refractory anemia (RA)/RA with ringed sideroblasts; treatment with a fixed‐dose versus a weight‐based ESA regimen; shorter interval between diagnosis and treatment initiation; and lower baseline serum erythropoietin level 8.