Background: Concern about the transmission of human immunodeficiency virus via blood has substantially increased the public's anxiety about the safety of the blood supply and has encouraged practices to minimize risks deriving from transfusions.
Study design and methods: To assess changes in transfusion practices in elective surgery as awareness of transfusion-transmitted human immunodeficiency virus emerged, 80 randomly selected patients per year undergoing elective total hip replacement in five calendar years between 1977 and 1989 at a large university teaching hospital were studied.
Results: Total blood use decreased significantly from an average of 3.3 units per patient in 1977 to 2.1 units per patient in 1989 (p = 0.0003). Autologous blood use increased from essentially zero in 1977 to 82 percent of total blood use in 1989 (p < 0.0001). The threshold hematocrit for postoperative transfusion of allogeneic blood (defined by use of logistic regression models) decreased from 30.1 percent (0.30) in 1977 to 26.7 percent (0.27) in 1989 (p = 0.01). As a result of these changes, the proportion of patients exposed to allogeneic blood decreased from 90 to 16 percent across the study period (p < 0.0001). The dramatic decrease in the use of allogeneic blood in elective total hip replacement surgery during the study period was due to decreased demand for blood during and after the operation and to a striking shift in the blood supply from allogeneic to autologous sources.
Conclusion: These findings demonstrate that physicians can appropriately alter practices when there are perceived health risks.