ABSTRACT Background Various differences in the healthcare system have been described between the United States (US) and Japan; however, the impact on clinical outcomes, particularly in severely injured older trauma patients, is not fully understood. We aimed to compare clinical outcomes of severely injured older trauma patients between the US and Japan using a nationwide trauma database in each country. Methods This is a retrospective study using the National Trauma Data Bank (NTDB) and Japan Trauma Data Bank (JTDB) from 2017 to 2021. The two datasets were queried for patients aged ≥ 60 years with severe injuries (injury severity score > 15). We excluded patients who were dead on arrival (DOA) and had missing outcome data. The primary outcome was in‐hospital mortality, and the secondary outcomes were hospital length of stay (HLOS) and disposition after hospital discharge. Results A total of 268,013 NTDB and 29,998 JTDB patients were included for the analysis. The overall in‐hospital mortality rate in the NTDB was significantly higher compared to the JTDB (14.4% vs. 10.5% p < 0.001). The median hospital length of stay was significantly longer in the JTDB than the NTDB (22 vs. 7 days, p < 0.001). The rate of prolonged hospital stay, exceeding 50 days, was significantly higher in the JTDB (16.5% vs. 1.2%, p < 0.001). In the 60–69 age group, there was a significant difference in the proportion of patients that were discharged home between the JTDB and NTDB (36.0% vs. 46.7%, p < 0.001). In both datasets, the proportions of patients discharged to home in the 80–89 age group were significantly lower compared to those in younger age groups ( p < 0.001, respectively) with more patients transferred to another hospital in the JTDB and more discharged to hospice or other facilities in the NTDB. Conclusions The results in this study suggest that there are significant outcome differences in severely injured older trauma patients between the US and Japan. Future research is warranted to identify underlying mechanisms of the outcome differences.
Takahashi et al. (2026) studied this question.