This article assesses the use and costs of blood transfusion during knee and hip surgery through a retrospective observational study of 92,223 discharged inpatients who had undergone knee or hip surgery from July 1, 2003, through June 30, 2004; a sample of US hospitals that participated in the Perspective Comparative Database (TM) (Premier Inc., Charlotte, NC) was used. Descriptive and multivariate analyses were performed to determine the use and costs of allogeneic blood transfusion (ABT). The average cost of ABT per user ranged from $387 (SD=$952) for red blood cells to $6585 (SD=$11,1 62) for cryoprecipitate. Utilization rates in the sample were as follows: antifibrinolytics, 0.14%; topical sealants, 3.24%; volume expanders, 3.89%; erythropoietin agents, 5.08%; and hypotensive anesthesia, 22.28%. Patients who were given volume expanders ($133.73, SD=$23.00, P <.01) or erythropoietin ($177.72, SD=$34.61, P <.01) had higher costs associated with ABT than did those who did not use volume expanders or erythropoietin. Patients who received hypotensive anesthesia (odds ratio [OR]=1.96; 95% confidence interval [CI], 1.87-2.06), a volume expander (OR=1.71; 95% Cl, 1.57-1.85), a topical sealant (OR=1.61; 95% Cl, 1.45-1.79), or an erythropoietic agent (OR=2.30; 95% Cl, 2.06-2.57) had a greater likelihood of ABT. Investigators concluded that most transfusion reduction techniques are underused, or they do not reduce the burden of ABT associated with knee or hip surgery.