Associations of anemia persistency with medical expenditures in Medicare ESRD patients on dialysis

Most end-stage renal disease (ESRD) patients begin renal replacement therapy with hemoglobin levels below the recommended US National Kidney Foundation Dialysis Outcomes Quality Initiative Guidelines lower level of 110 g/L. Although most patients eventually reach this target, the time required varies substantially. This study aimed to determine whether length of time with below-target hemoglobin levels after dialysis initiation is associated with medical costs, and if so, whether intermediate factors underlie the associations. US patients initiating dialysis in 2002 were studied using the Centers for Medicare and Medicaid Services ESRD database. Anemia persistence (time in months with hemoglobin below 110 g/L) was determined in a six-month entry period, and outcomes were assessed in the subsequent six-month follow-up period. The structural equation modeling technique was used to evaluate associations between persistent anemia and medical costs and to determine intermediate factors for these associations. The study included 28,985 patients. Mean per-patient-per-month medical cost was $6267 (standard deviation $5713) in the six-month follow-up period. Each additional month with hemoglobin below 110 g/L was associated with an 8.9% increment in medical cost. The increased cost was associated with increased erythropoietin use and blood transfusions, and increased rates of hospitalization and vascular access procedures in the follow-up period.