Fig. 1

Conceptualization of the study. Among trauma patients who survived for > 48 h, some patients suffered from complications, while others did not; the proportion of patients with complications is the “complication rate,” which is one of the outcome indicators. Those who suffered from complications were more likely to die than those who did not suffer from complications, i.e., the rate of “failure-to-rescue (FTR),” which is another outcome indicator, is naturally more than the rate of “non-precedented deaths.” Overall in-hospital mortality comprises these components. However, unlike reports of elective surgery, it has been controversial whether complication rate or FTR explains more variations in in-hospital mortality. In addition, FTR in trauma complication studies includes not only patients who have undergone surgery but also those who have not undergone surgery; this is inconsistent with studies on elective surgery. We investigated this research question in the present study