In this retrospective multicenter study, the authors reconfirm the association between RBC transfusion and mortality in 318 patients admitted for aneurysmal subarachnoid hemorrhage. After adjustement for probability of receiving RBC transfusion, Apache IV and nadir hemoglobin concentration, transfusion remained independently associated with hospital mortality. Nevertheless, the question remains: is mortality due to the deleterious effects associated with RBC transfusion or, in contrast, is the low hemoglobin just a marker of severity of illness and mortality?

– Michael Piagnerelli