Epidemiology and Outcomes of Severe Traumatic Brain Injury: Regional Trauma Center in Incheon, Korea, 2018–2022

Traumatic brain injury (TBI), which refers to head trauma leading to brain dysfunction, is a global health concern with wide-ranging implications,8) affecting individuals, families, and healthcare systems worldwide. The study of the epidemiology and outcomes of TBI is vital for developing effective healthcare policies and trauma management protocols, particularly in Korea, which mirrors global trends.

With its high population density and urbanization rate, Incheon presents unique challenges in TBI management. Moreover, the demographic and socioeconomic characteristics of the city potentially influence the prevalence and nature of TBI cases. Therefore, examining TBI in the context of the healthcare resources and infrastructure of Incheon is crucial, providing insights into urban TBI trends and healthcare efficacy.

Despite the global recognition of ’the impact of TBI in the healthcare system and socioeconomic status of a country, comprehensive, region-specific studies regarding the occurrence and management of TBI in Korea are lacking. The existing literature often generalizes or omits local factors crucial to understanding the epidemiology and outcomes of TBI. This study aimed to fill this gap by investigating the regional characteristics and outcomes of patients with severe TBI in Incheon, utilizing data from a regional trauma center. This approach sought to deepen our understanding of ’the impact and management of TBI within this urban context.

This retrospective study was approved by the Clinical Research Ethics Review Committee of the Gachon University Gil Medical Center (approval No. GBIRB2023-042). Given its retrospective design, the requirement for informed consent was waived. All procedures adhered strictly to the relevant guidelines and regulatory standards outlined in the Declaration of Helsinki.

The average age of patients with severe TBI was 54 years, with the highest incidence in the 60–79 years age group at 37.4%, followed by the 40–59 years age group at 31.6%. According to Korea’s demographic statistics announced by the Ministry of the Interior and Safety in December 2023,18, 19) the 50–59 years age group constitutes 17.2% of the total population of Incheon, followed by the 40–49 years age group at 16.0%. In addition, the 40–59, 20–39, and 60–79 years age groups represent 33%, 26%, and 21% of the total population of Incheon, respectively. The high incidence of severe TBI in the 40–59 age group aligned with the age distribution in Incheon. However, the 60–79 age group showed a relatively high incidence of severe TBI (37.4%) relative to its population percentage (21%), possibly due to increased risk of falls associated with age-related decline in muscle strength and reflexes. This trend was even more pronounced in the over-80 age group, where despite only making up 3% of the population, they accounted for 8.8% of accident cases, indicating a significantly higher incidence relative to their population proportion compared with that of other age groups.

In Incheon, the gender ratio in the population is evenly split between men and women.18) However, the incidence of severe TBI in men was approximately 3 times higher than that in women. This disparity may have been influenced by factors such as occupational types and alcohol consumption rates; however, due to a lack of specific data, the exact causes remain unclear.

The number of hospitalized patients by year showed a sharp decline in 2020 and 2021 but then increased again in 2022. It is thought to be related to coronavirus disease 2019 (COVID-19). Previous studies have reported a decrease in the overall number of trauma patients due to a decrease in non-essential activities during the COVID-19 pandemic,15, 25) and this study also showed similar results.

In this study, the most common injury mechanisms for severe TBI were traffic accidents, followed by falls. This aligned with the findings by Jeong et al.12) from their 2018–2021 national survey on severe TBI. They reported that trauma centers predominantly attended to cases of traffic accidents and falls as injury mechanisms, whereas nontrauma centers had more cases of slip-downs, followed by traffic accidents. The similarity between the results of this study and the national data on trauma centers suggested the existence of an appropriate categorization of patients based on injury mechanisms between trauma and nontrauma centers, at least in the Incheon region.

Although comparing our results with data from hospitals nationwide was not possible due to the lack of trauma score data from nontrauma centers, the injury severity assessed using the GCS and trauma scoring systems in this study showed no significant differences from the results of trauma centers nationwide.13)

Regarding the hospital arrivals of patients with severe TBI, direct admissions, primarily via public EMS, were the most common. Transfers often involved private ambulance services due to limitations in the use of public EMS in the Korean emergency medical system. Incheon has been operating a doctor helicopter since 2011, with emergency medical specialists providing care during the transport of patients from remote areas. Currently, 8 hospitals nationwide use helicopters as a vital part of their emergency transport system. Unique to Incheon since 2019 is the operation of a doctor car, where trauma surgeons and nurses respond directly to emergency scenes.1) This service is mainly used for severe trauma patients with significant bleeding, and in this study, all 4 cases using the doctor car involved polytrauma patients with substantial bleeding.

Postinjury complications occurred in approximately 16% of patients with severe TBI, with pneumonia, AKI, and DVT being the most common. Prolonged bedridden states and ventilator use in patients with severe TBI likely contribute to the higher rates of pneumonia and DVT.4, 24) In polytrauma patients, AKI can result from causes such as shock-induced renal ischemia and rhabdomyolysis.7) Moreover, factors such as hypernatremia and osmotic therapy may increase AKI risk in patients with TBI.24) Considering that these complications significantly affect outcomes, careful monitoring and proactive preventive measures are crucial.

In this study, the mortality rate for patients with severe TBI was 44%, matching the expected survival rate of 56% as indicated by TRISS. Moreover, after 6 months, 70% of patients showed unfavorable outcomes as measured by GOS. Interestingly, a review of 15 previous studies on severe TBI outcomes revealed considerable variability: 21%–79% for mortality and 41%–85% for unfavorable outcomes, with an overall average of 43.6% for mortality and 52.9% for unfavorable outcomes.2, 3, 5, 6, 9, 10, 11, 14, 16, 17, 20, 21, 23, 26) Compared with the findings of the abovementioned studies, our study found no significant difference in mortality rates for severe TBI cases. However, the rate of unfavorable outcomes in our study was higher than that reported in these studies, also exceeding the 72.7% rate of unfavorable outcomes reported for trauma centers nationwide in Korea by Jeong et al.12) These comparisons, while not exact due to differences in patient cohorts among studies, highlight the need for improved treatment guidelines and emergency medical policies to enhance favorable outcomes in patient with TBI.

For trauma patients, including those with head injuries, the EMS system is crucial for securing the “golden time,” which is the critical period immediately following an injury. The EMS system is designed to provide swift and effective medical services in emergencies. It is divided into 2 main stages based on the location of care: the prehospital and inhospital stages. The prehospital phase includes emergency medical communication systems and ambulance services, whereas the inhospital phase encompasses medical institutions such as emergency and trauma centers, specialized emergency medical personnel, and emergency treatments. Effective implementation and operation of the EMS system require collaboration among governments, local authorities, medical institutions, ambulance services, communities, and research and education institutions.22) In 2020, Incheon initiated a pilot project to establish a regional trauma care system. This project involves the collaboration among the Incheon city council, fire headquarters, coast guard, Incheon research institutes, regional trauma centers, emergency medical institutions, and private transportation companies. The aim was to establish a regional trauma governance system to reduce preventable trauma death rates by ensuring timely and appropriate transport and referral of trauma patients. If this trauma system in the Incheon area is effectively and well-organized, a significant improvement in the outcomes of trauma patients, including those with severe TBI is expected in the future.

This study had several limitations. First, its focus on a single trauma center may not fully represent the characteristics of patients with severe TBI across the entire Incheon region. Further analysis incorporating data from local emergency medical centers is needed to address this. Second, the method of extracting postinjury complication data based solely on disease codes may have led to the underestimation of complication incidences. Third, the inability to analyze data on accident locations limited our insights into the unique challenges of the geographical characteristics of the Incheon island area and its emergency transport system. In addition, the importance of time interval analysis is emphasized because “golden time” is crucial to TBI patients. Still, because injury time was recorded only when public EMS was used as a mode of transport, it was impossible to analyze the time from injury to hospital arrival by transportation method. Future data collection efforts in collaboration with emergency services are crucial. Finally, this study did not evaluate factors such as prehospital management, TBI management strategies, and brain computed tomography (CT) findings, including the Rotterdam CT score, which are vital in assessing TBI outcomes. Future research should aim to analyze these factors to better understand their impact on TBI outcomes.

As the inaugural research effort at the regional trauma center in Incheon, this study explored the epidemiology and outcomes of patients with severe TBI. Despite data limitations, it offered valuable insights regarding TBI outcomes by comparing local data with national statistics. Future research focusing on periodic assessments of severe TBI and incorporating additional data, particularly from the prehospital stage, is anticipated to enhance the functionality of emergency medical and trauma systems in Incheon and improve outcomes for patients with severe TBI.