Patterns of use of group O, Rh-negative red cells in a large metropolitan area and an action plan to control utilization

BACKGROUND: In southeastern Michigan, the group O, Rh-negative (O-) red cell supply was below emergency levels during one-sixth of 1994, despite 43-percent overcollection of O- red cell units relative to the size of the O- patient population. O- red cell units are overutilized because of their universal ABO and Rh compatibility. This study evaluated how hospitals in a large metropolitan area utilized O- red cell units, so that strategies could be devised to reduce O- usage. STUDY DESIGN AND METHODS: Through an O- red cell utilization survey, 56 hospitals were encouraged to collect three months' worth of transfusion data, either prospectively or retrospectively. O- usage was compared to total red cell usage and categorized into transfusions to O- patients, those to non-O- patients, and the number of O- units that outdated. RESULTS: Of 40,616 units transfused in 38 hospitals, 3,535 (8.7%) were O-; 71 percent of the O- units were transfused to O- patients, 28 percent were transfused to non-O- patients, and 1 percent outdated. Hospital transfusions to O- patients appeared to correlate with the racial makeup of the patient population, while hospital transfusions to non-O- patients appeared to correlate with hospital size and the hospital's transfusion practices. CONCLUSION: O- red cell usage in a hospital is dependent on the racial and ethnic mix of the hospital's patient population, the amount of transfusion activity, and the hospital's transfusion practices. An understanding of the dynamics of O- usage allowed the development of strategies to decrease O- utilization.