The epidemiology of multicomponent blood transfusion: a systematic review.

We performed a systematic review to describe the prevalence of multicomponent blood transfusion and, as a secondary objective, to determine patient characteristics and outcomes associated with multicomponent transfusion. There is a lack of literature on the epidemiology of multicomponent transfusion as most studies concentrate on a single blood product and its utilisation. Patient care and blood management can be optimised by better understanding the patients who receive multicomponent transfusions. The databases Medline, EMBASE and the Cochrane Library of Systematic Reviews were searched. Observational cohort and cross-sectional studies of hospital patients reporting on multicomponent transfusion prevalence or on patient characteristics and outcomes associated with multicomponent transfusion were included. A descriptive synthesis of studies was performed. A total of 37 eligible studies were included. It was found that multicomponent transfusion prevalence varied greatly by patient population and by the combination of blood products given in the multicomponent transfusion. Multicomponent-transfused patients included burn, cardiac surgery, liver surgery and transplant, cancer, infectious diseases, trauma and intensive care unit patients. Five studies found associations between multicomponent transfusion and adverse health outcomes; however, these findings are likely confounded by indication. The overall quality of evidence was low given a fair-to-poor individual study quality, inconsistent multicomponent transfusion prevalence estimates and confounding by indication. Further research is needed to better understand the epidemiology of multicomponent transfusion, including studies on multicomponent transfusion in haematological cancer patients and studies looking for patient characteristics that can better predict multicomponent transfusion need.