BACKGROUND: Our objective was to characterize inpatient blood use by the US elderly population during 2001. As the US population ages the demand for blood is expected to grow. There have been no comprehensive studies, however, detailing blood use by the elderly in the United States.

STUDY DESIGN AND METHODS: A descriptive cross-sectional study of blood utilization was conducted with the 5 percent Medicare Provider Analysis and Review (MedPAR) data file obtained from the Centers for Medicare and Medicaid Services (CMS). Each record of the file represented a billing record of an inpatient stay. Blood use was identified by either a nonzero blood pints furnished quantity or a procedure code for transfusion of whole blood or red blood cells (RBCs).

RESULTS: Among 635,700 stays, 43,220 (6.8%) recorded transfusion of whole blood or RBCs. Blood use prevalence was approximately 4.5 times higher for stays with at least one medical procedure compared to stays without procedures. Of 15,579 stays with number of blood pints furnished recorded, the top 20 principal procedures with the largest quantities of blood accounted for about 56 percent of total blood pints furnished; however, these procedures represented only about 19 percent of all stays.

CONCLUSION: Our study shows a strong association between medical procedures and blood use among inpatient stays for the elderly. Some of the highest blood utilization occurred with surgical procedures. More precise information on blood utilization may serve as the basis for estimating risks associated with blood transfusion and may inform decisions that maintain an adequate supply of blood.