Temporal trends in red blood transfusion among US dialysis patients, 1992-2005

Studies addressing patterns and trends in red blood cell transfusion use in US hemodialysis patients surprisingly have received little attention in the last decade.

Retrospective cohort study.

Point prevalent (as of January 1 of each calendar year 1992 to 2005) dialysis patients with Medicare Part A and Part B as primary insurance (n = 77,347 in 1992, n = 164,933 in 2005). The 6 months preceding January 1 of each year were used to assemble a comorbidity profile based on administrative claims data.

Hemoglobin levels, patient characteristics, comorbid conditions.

Blood transfusion events obtained from Part A and Part B files using code files for both whole and packed red blood cell transfusions and hemoglobin levels.

Comorbid conditions were defined by the presence of 1 or more inpatient/outpatient institutional claims (inpatient hospitalization, skilled nursing facility, or home health agency), 2 or more outpatient or physician/supplier claims, or 1 or more outpatient and 1 or more physician/supplier claims for atherosclerotic heart disease, congestive heart failure, cerebrovascular accidents/transient ischemic attacks, peripheral vascular disease, other cardiovascular diseases, chronic obstructive pulmonary disease, gastrointestinal disorders, liver disease, arrhythmia, and diabetes mellitus.

Raw transfusion rates decreased in both outpatient and inpatient settings from 535.33/1,000 patient-years for 1992 prevalent dialysis patients to 263.65/1,000 patient-years in 2005 (P for trend < 0.001, 1992 versus 1999 and 1999 versus 2005). Adjusted rates decreased similarly. This phenomenon could not be explained by changes in case mix.

Cause, effect, and confounding cannot be separated in this observational study. The accuracy of blood transfusion billing data is unknown. Temporal trends may be related to factors other than erythropoiesis-stimulating agent use.

Transfusion events in hemodialysis patients decreased more than 2-fold from 1992 to 2005; most of the decrease occurred in the first 5 years after erythropoietin was introduced.