Evidence-Based Medicine: Principles and Values as Illustrated by the Case of Patient Blood Management

Evidence-based medicine is considered 1 of the 15 great inventions in medicine. It aims to remove bias in medical decision-making as much as possible through a rigorous process. In this article, the principles of evidence-based medicine are illustrated using the case of patient blood management (PBM). Acute or chronic bleeding, iron deficiency, and renal and oncological diseases may lead to preoperative anemia. To compensate for severe and life-threatening blood loss during surgery, doctors transfuse red blood cells (RBCs). PBM is an approach to take care of patients at risk for anemia, which includes detecting and treating anemia before surgery. Alternative interventions to treat preoperative anemia are the use of iron supplementation with or without erythro-stimulating agents (ESAs). The best available scientific evidence today indicates that preoperative intravenous (IV) or oral iron monotherapy may not be effective to reduce RBC utilization (low-certainty evidence). Preoperative IV iron supplementation in addition to ESAs is probably effective to reduce RBC utilization (moderate-certainty evidence), whereas oral iron supplementation in addition to ESAs may be effective to reduce RBC utilization (low-certainty evidence). The adverse events of preoperative oral/IV iron and/or ESAs and their impact on patient-important outcomes (morbidity, mortality, quality of life) remain unclear (very low-certainty evidence). Since PBM is a patient-centered approach, emphasis on monitoring and evaluation of patient-important outcomes in future research is urgently needed. Finally, the cost-effectiveness of preoperative oral/IV iron monotherapy is unproven, whereas preoperative oral/IV iron in addition to ESAs is extremely cost-ineffective.