Variation in a medical faculty's decisions to transfuse. Implications for modifying blood product utilization.

Previous studies have identified disconcerting differences in transfusion practices among physicians. This article investigates decisionmaking on transfusion by a medical school faculty. One hundred fourteen physicians indicated their propensity to transfuse 24 hypothetical patients who varied systematically in four clinical cues. Physicians agreed with transfusion for a widely divergent number of these patients (mean, 14.6; standard deviation, 5.5; range, 0 to 24). Although the physicians agreed on the order of importance of the clinical cues, they varied significantly in the importance they empirically attributed to the cues and in their thresholds for transfusion. Aside from a slightly higher propensity to transfuse by general internists, differences in decisionmaking were not attributable to physician-based variables. The wide variability in decisionmaking among physicians in the face of agreement on the order of importance of clinical cues suggests that quality assurance programs, and guidelines that only list the cues that ought to influence transfusion decisions, have low potential to achieve blood-product conservation.