Predictors of ESA use in the non-dialysis chronic kidney disease population with anemia

Background: Anemia is a common complication of chronic kidney disease (CKD), but anemia treatment may be less comprehensive than guidelines suggest. Methods: The study population (n = 11,754) included general Medicare recipients with Parts A and B coverage before January 1, 2001, aged ≥65 years on January 1, 2001, and alive with Medicare as primary payer through December 31, 2001. Time-dependent proportional hazards models were used to investigate predictors of erythropoiesis-stimulating agent (ESA) use, adjusted for comorbid conditions and severity-of-disease variables as time-dependent, and age, sex, and race as fixed variables. ESA use was defined during 2002 and time-dependent variables during 2001-2002. Results: Only 839 patients (7%) received ESAs. Characteristics significantly predictive of ESA use (p < 0.05) were: outpatient specialty services, nephrology and hematology/oncology/medical oncology (RR 6.92); outpatient specialty services, hematology/oncology/medical oncology (RR 6.02); outpatient specialty services, nephrology (RR 3.44); inpatient principle procedure, other operations on vessels (RR 1.68); transfusions (RR 1.54), hypertension (RR 1.50); congestive heart failure (RR 1.34); home oxygen (RR 1.28). Conclusions: Access to anemia treatment may be an important marker for access to CKD care. Clinical trials are needed to assess effects of early referral and more comprehensive anemia treatment.