Background: Blood transfusions are one of the most common hospital procedures in the United States, often associated with adverse events, high costs, and limited availability [1-3]. Prior literature has shown that non-transfusion medicine physicians have poor to intermediate transfusion medicine knowledge (TMK) [4-7]. While physicians often use hemoglobin (Hgb) levels to determine when transfusion is appropriate, some guidelines have recommended that physicians rely on symptoms of anemia instead [8-10]. This cross-sectional survey study explores transfusion practices of physicians and advanced practice providers (APPs) across multiple departments and training levels at a US academic medical center to evaluate adherence to current guidelines.
Methods: This study was conducted with Institutional Review Board (IRB) exempt category approval for protocol #2590. All subjects participated voluntarily with no monetary compensation, and consent was obtained prior to participating in the survey. Using Qualtrics platform, a 14-question anonymous survey link was emailed to residents, attending physicians, and APPs from different medical, surgical, and anesthesia departments, with a total of 932 recipients. The questionnaire items were designed to cover the provider’s practice setting (4 items), diagnosis and definition of anemia (3 items), self-perceived transfusion behavior (1 item), treatment of anemia using packed red blood cells (3 items), and transfusion threshold for 3 unique clinical scenarios (3 items). The survey was open for a period of 2 months with bi-weekly email reminders.
Results: Of the 932 recipients, 121 responses were collected (13%). A majority of responses came from attending-level physicians (54.5%). Responses were classified into medical (47.1%), surgical (28.1%) and anesthesia (24.8%) specialties. Anemia in men (Hgb concentration of < 13g/dL) was correctly stated in 39.7%, and anemia in women (Hgb concentration < 12 g/dL) was correctly stated in 51.2%. In the case of anemia in a hemodynamically stable (HDS) patient without cardiovascular disease, most providers (88.4%) indicated a hemoglobin level of < 7g/dL as the transfusion threshold. In the case of anemia in a HDS patient with stable coronary artery disease (CAD), 49.6% of providers reported a transfusion threshold of < 7g/dL. In the case of anemia in a HDS patient hospitalized due to an acute coronary syndrome (ACS), 54.5% of providers reported using a hemoglobin threshold of < 8g/dL.
Conclusions: In this cross-sectional survey study, we performed an assessment on how physicians and APPs define anemia and implement transfusion guidelines. Among the 121 participating providers, hemoglobin values for anemia were clearly defined for women, but were more weakly defined for men. While the transfusion threshold is widely known as 7g/dL in patients with no cardiovascular disease, providers are more restrictively transfusing patients with stable CAD at a level of 7g/dL despite the Association for the Advancement of Blood & Biotherapies (AABB) guidelines recommending 8g/dL [11]. Furthermore, despite there being no Hgb transfusion threshold recommendation for ACS, most providers indicated transfusing at 8g/dL. These findings highlight that although providers adopt restrictive transfusion strategies, there is need for further education on the definition of anemia and on transfusion practices in patients with CAD.
