This study examined emergency medical service (EMS) transportation patterns for adult trauma patients before and after establishing a level 1 regional trauma center (RTC) and to evaluate the transportation approach after prehospital severity screening.

This was a retrospective observational study of trauma patients aged ≥18 years admitted via EMS to the emergency department or a level 1 RTC, 1 year before to 3 years after RTC establishment. Patients with an Injury Severity Score (ISS) in the patient registration system were selected. Analyses were performed to determine transportation pattern changes by comparing patients pre- and post-RTC establishment and by yearly comparisons over the 4-year study period using the Mann-Whitney U test and chi-square test.

Overall, 3,587 patients were included. The mean ISS was higher in the post-RTC group (n=2,693; 10.63±8.90, median 9.00) than in the pre-RTC group (n=894; 9.44±8.20, median 8.00; p<0.001). The mean transportation distance (9.84±13.71, median 5.80 vs. 13.12±16.15 km, median 6.00; p<0.001) was longer in the post-RTC group than in the pre-RTC group. Furthermore, proportionally fewer patients were transported from an area in the same city as the RTC after establishment (86.1% vs. 78.3%; p<0.001). Yearly comparisons revealed a gradually increasing trend in the hospital death rate (p_trend=0.031).

After establishing a level 1 RTC, the EMS transportation of severe trauma patients increased gradually along with the long-distance transportation of minor trauma patients. Therefore, improved prehospital EMS trauma severity assessments and level 1 RTC involvement in patient classification in the prehospital phase are necessary.