Trauma, the eighth main cause of death worldwide, is also a major cause of death in the Republic of Korea [1]. Particularly, in young people (10 to 30 years of age), intentional self-harm (suicide) and road traffic accidents are the top two causes of death [2]. Trauma causes socioeconomic losses owing to serious sequelae and delayed return to daily life [3]. The 2009–2010 rate of preventable trauma fatalities in the Republic of Korea was 29.8%, a level higher than those of other developed countries (10–20%), and this discrepancy spurred the establishment of level 1 regional trauma centers (RTCs) in Korea [4]. In 2012, in support of level 1 RTCs, a project was initiated to establish such centers equipped with appropriate facilities, equipment, and manpower. This project aimed at providing severe trauma patients with optimal treatment (including emergency surgery) within 24 hours after hospital arrival, 365 days per year. By evenly distributing Korea’s RTCs such that treatment can commence for trauma patients within an hour of arrival, it was expected that the preventable trauma fatality rate could be reduced to <20% [3].

By 2020, 15 level 1 RTCs were being operated in Korea. Governmental efforts have focused on establishing a standard operating system for RTCs by reviewing RTC operation criteria, as well as by conducting operational-level examinations. Since level 1 RTCs are established to provide intensive treatment to a unique group of severe trauma patients, the scope and type of services should differ from those of emergency departments (EDs).

Severe trauma patients, who comprise the primary patient group treated at level 1 RTCs, are transported via emergency medical services (EMS; in Korea EMS include 119 emergency medical technicians, who provide primary care at the prehospital stage and during transportation to the hospital). To provide optimal treatment, RTCs need to be organically and independently operated. However, EMS personnel must understand that level 1 RTCs should provide specialized treatment to trauma patients only, unlike the broader range of services provided in the ED. A misunderstanding also exists that a regional trauma system can be operated simply by establishing trauma centers. Due to these misconceptions, the number of minor trauma patients at level 1 RTCs has continued to increase [5].

Thus, to prevent problems from arising, EMS must actively transport severe trauma patients to level 1 RTCs and distribute the transportation of uncomplicated minor trauma patients. Furthermore, it is necessary to compare EMS transportation before and after level 1 RTC establishment. However, no previous study anywhere in the world has compared EMS trauma patient transportation before and after level 1 RTC establishment. Accordingly, this study aimed to compare the EMS transportation patterns of trauma patients (including adult trauma patients with injuries of various severity transported by EMS, patient transportation time and distance, and the area the patient was transported from) before and after level 1 RTC establishment.

An examination of minor and severe trauma patients classified using the ISS-based criterion showed that the proportion of minor trauma patients decreased, while that of severe trauma patients increased after the trauma center was established. The hospital death rate increased in severe trauma patients after the establishment of the trauma center, but the mean ISS of severe trauma patients did not differ between pre- and post-establishment.

The mean transportation distance was higher after the trauma center opened than before it was established. The separate analyses of transportation distance for minor and severe trauma patients also showed the same pattern, with an increased transportation distance after the trauma center opened. According to the yearly comparisons from 1 year before the trauma center opened to 3 years after, the mean ISS and the proportion of severe trauma patients increased in the 3 post-opening years compared with 1 year before the opening. Further, mean transportation distance and time increased in the 3 post-opening years for both minor and severe trauma patients, similar to the findings of the analyses conducted to compare the pre- and post-opening findings of all trauma patients.

In the analysis by accident district, in trauma patients initially transported from an area in the same city as the trauma center, the proportions of minor and severe trauma patients, as well as mean transportation distance and time, were similar pre- and post-opening of the trauma center. In patients transported from an area outside of the city, the mean ISS and mean transportation distance showed a significant difference pre- and post-opening. For severe trauma patients transported from an area outside of the city, the mean transportation time and distance increased after the trauma center opened.

The study findings demonstrate positive changes after the establishment of the level 1 RTC. That is, EMS transported increasingly more severe trauma patients or patients suspected of having severe trauma to the RTC. However, given the finding that the mean transportation time and distance in minor trauma patients also increased, it seems that minor trauma patients still continued to be transported over long distances to the trauma center. The hospital mortality rate is thought to have increased after RTC establishment because there was a much higher proportion of patients with head and neck injuries after the trauma center opened than previously, and fatalities were higher for patients with head and neck injuries than for those with other injury types [6].

The prehospital patient assessment currently used in Korea is based on the “Guidelines for EMS Emergency Response”, first established in 2011 [7]. As specified in the prehospital care report, the level of consciousness, pupillary reflex, and vital signs are evaluated; and in severe trauma cases, an assessment is performed in accordance with the detailed severe trauma assessment table. These guidelines are based on the Guidelines for Field Triage of Injured Patients proposed in the US in 2011. According to these guidelines, the hospital to which trauma patients are transported is determined on the basis of the trauma severity, assessed based on physiological criteria, anatomical area, the mechanism of injury, and other factors determined at the discretion of EMS [7,8].

In a study conducted before the establishment of level 1 RTCs, Kim et al. [9] compared trauma severity assessments performed at the hospital to those performed by EMS in the field and found that only the vital signs assessment showed medium-level agreement, while the physical examination and the assessment of the mechanism of injury did not show high agreement. Hence, it is not easy to determine the level of hospital to which trauma patients should be transported based on severity assessments conducted only using the current guidelines for EMS emergency response. Further, it is impossible to use ISS at the prehospital phase to determine which patients should be transported to level 1 RTCs, because the ISS is derived after several tests are performed and a diagnosis has been made at the hospital. Recently, Lee et al. [10] reported that a prehospital evaluation of patient severity by measuring the Glasgow Coma Scale (GCS) and Revised Trauma Score (RTS) was helpful in assessing the severity of trauma patients. To assess trauma severity, it is necessary to evaluate the validity and utility of GCS or RTS, and the assessment items should be revised to follow, in a more multifaceted manner, the current guidelines for EMS emergency response and guidance in the prehospital care report.

Lastly, it is necessary to ensure that severe trauma patients who require treatment that can be provided only by level 1 RTCs are appropriately transported by continuing to improve the EMS guidelines for patients’ transportation, as well as the table of detailed severe trauma assessment items in the prehospital care report. To do so, the EMS data on patient transportation (including detailed trauma case records) gathered so far should be made completely public so that additional research can be conducted and EMS quality control can be strengthened. It is thought that through this process, disagreements between EMS and level 1 RTCs with respect to trauma patient transportation will be resolved.

In addition, improvements can be made by continuing to train EMS personnel, establishing a trauma system consisting of level 1 RTCs and local autonomous governments, and forming consortiums to organically link EMS within the region. At some university hospital trauma centers in the United States, trauma center nurses responsible for patient classification play the role of a central control center for EMS in their immediate communities. They participate in activating the trauma team at the hospital by providing consultation on the classification and transportation of ED patients and monitoring patient transportation in real time [5]. In Korea, level 1 RTCs should be involved more proactively in prehospital patient classification and patient transportation through direct communication between trauma center medical staff and EMS.

This study has a few limitations. First, the study analyzed trauma patients admitted to a single level 1 RTC. Due to regional limitations, the study sample may not be representative of level 1 RTCs nationwide; therefore, the findings should be interpreted with caution. In the future, multicenter studies should be conducted to examine data at the national level. Second, trauma patients aged <18 years were excluded from the study. It is not common for the ISS to be calculated in children, and the score that distinguishes between severe and minor trauma patients when using the ISS differs from that used for assessing adults [11]. Third, the methodology used a retrospective study design. Because the study was based on the review and analysis of medical charts and prehospital care reports, possible errors owing to incorrect recordings and missing information could not be avoided. Finally, because the scope of information that can be obtained from prehospital care reports is limited, factors such as the traffic situation impacting patient transportation time and distance or the situation of other hospitals were not considered in analysis. Additionally, the data entered into the table of detailed severe trauma assessment items and other detailed data on severe trauma patients transported to the level 1 RTC were not available to the authors; therefore, it was impossible to confirm whether or not EMS transported patients in accordance with the guidelines for EMS emergency response. In the future, these data should be disclosed so that research can be conducted on EMS prehospital trauma patients’ transportation to level 1 RTCs.

No previous study has yet compared EMS trauma patients before and after RTC establishment. This study confirmed changes in EMS transportation patterns before and after the establishment of the trauma center for. In the future, a nationwide survey of patients transported to RTCs by EMS is needed. A pre-hospital evaluation study of EMS is also needed, with the detailed evaluation of severe trauma.

Although EMS transportation of severe trauma patients to the level 1 RTC increased after the trauma center opened, long-distance transportation of minor trauma patients persisted after the establishment of a level 1 RTC. To address this problem, EMS should improve the methods used for prehospital trauma severity assessment, and level 1 RTCs should also be involved in the prehospital phase for severity assessment and patient transportation in the region.