Date of Award


Document Type


Degree Name

Doctor of Health Administration


College of Health Professions

First Advisor

Annie N. Simpson

Second Advisor

Donald S. Likosky


Background: Despite evidence-based guidelines informing indications for transfusions, unwarranted variability in performance exists across cardiac surgical programs. We aimed to identify to what extent distinguishing patient and procedural characteristics can explain center- level transfusion variation during coronary artery bypass grafting (CABG) surgery. Methods: We evaluated 22,272 adult patients undergoing isolated CABG using cardiopulmonary bypass between July 1, 2011 and July 1, 2017 across 43 centers. Iterative multilevel logistic regression models were constructed using patient demographic, preoperative risk factors, and intraoperative conservation strategies to progressively explain center-level transfusion variation. Results: Nearly one-third (n=7241, 32.5%) of patients received at least one transfusion. Rates varied between 10.9% to 59.9% across centers. Among the models explaining center-level transfusion variability, the intraclass correlation coefficients varied between 0.072 to 0.136, while the coefficient of variation varied between 0.29 to 0.40. Conclusion: The results suggest that variation in center-level RBC transfusion cannot be explained by patient and procedural factors alone. Investigating organizational culture and programmatic infrastructure may be necessary to better understand variation in transfusion practices.


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