Figure 2.

Patient flow and cohort creation. ^aMonths with missing hemoglobin values or hemoglobin values < 0 g/dL or >20 g/dL were excluded from the analysis. The first date of each month with a valid hemoglobin value was defined as a potential index date. ^bMonths with missing weight values or weight values < 20 kg or >350 kg were excluded from the analysis. Monthly recombinant human erythropoietin (rhEPO) dose was calculated and converted to weekly dose. Hyporesponders were defined as described in the inclusion criteria. ^dPatients were excluded in this step mainly due to no Part D coverage, fewer than 6 months continuous eligibility before the index date, and Medicare was not the primary payer during the 6-month period. ^eHereditary hemolytic anemias were identified in the Medicare claims by International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code 282. Abbreviation: ERI, erythropoietin resistance index.