Takayama W, et al. - Researchers assessed the influence of the difference in the ABO blood type on mortality in patients with severe trauma in two tertiary emergency critical care medical centers in Japan, using univariate and multivariate competing-risk regression models. Patients with trauma with an Injury Severity Score (ISS)>15 were included. In the multivariate analysis adjusted for age, ISS, and the Revised Trauma Score (RTS), the effect of blood type O on the outcomes was evaluated using regression coefficients. Findings demonstrated a significant association of blood type O with high mortality in severe trauma patients. Furthermore, blood type O might have a great impact on outcomes.