Objective
The Trauma and Injury Severity Score (TRISS) has been used to predict trauma patient mortality and to assess the quality of trauma care systems. The goal of this investigation was to develop a modified trauma-related injury severity score (termed the TRISS-D) for predicting disability in acute trauma patients.
Methods
We used data collected by emergency medical services and entered into the Korea Centers for Disease Control and Prevention severe trauma database. The TRISS-D was based on age category (0–14, 15–54, ≥55 years), the Revised Trauma Score, and the Injury Severity Score. The outcome measures were severe disability and worsening disability. Worsening disability was defined as a lower Glasgow Outcome Scale score at hospital discharge than before the traumatic incident. Two types of cases were examined: those with penetrating or blunt injuries (group 1) and those with severe head injuries (group 2). We assessed the discriminatory power of the TRISS-D by calculating the area under a receiver operating characteristic curve (AUROC).
Results
The database comprised 14,791 patients; overall, 3,757 (25%) had severe disability and 6,018 (41%) had worsening disability. For severe disability, the AUROC (95% confidence interval) for the TRISS-D was 0.948 (0.944–0.952) in group 1 and 0.950 (0.946–0.954) in group 2. The corresponding values for worsening disability were 0.810 (0.803–0.817) and 0.816 (0.809–0.823), respectively.
Conclusion
The TRISS-D showed excellent discriminatory power for severe disability and very good discriminatory power for worsening disability.

Objective
To analyze motor vehicle accidents in two different traffic environments and compare differences in severity between both regions.

Methods
Injury data were collected by the Emergency Medicine and Traffic Accident Research Team as part of the Korean In-Depth Accident Study. Patients admitted to emergency medical centers located in Wonju, Gangwon province (population 345,143, rural, group A) and Bucheon, Gyeonggi province (population 870,735, urban, group B) between January 2011 and December 2017 were included for analysis. Injury severity was classified into four categories based on Injury Severity Score (ISS): minor (1≤ <9), moderate (9≤ <15), major (15≤ <25), and critical (≥25).

Results
Overall, 1,807 patients were included (group A, 1,484; group B, 323). There was a higher proportion of daytime accidents, accidents involving larger cars, passenger injuries, and accidents involving lack of seat belt use in group A than in group B. The mean ISS value was 8.98 in group A and 4.62 in group B (P<0.001). Minor (20.4% vs. 10.8%) and major/critical (15.7% vs. 5.0%) injuries were more frequent in group A than group B (P<0.001). Patient ratios (A/B) for each ISS classification were 0.76 (minor), 1.89 (moderate), 3.43 (major), and 2.77 (critical). The factors showing a significant relationship with severity were driver’s seat (P=0.037) and no seat belt (P<0.001).

Conclusion
Patients in a rural city who visited the emergency room owing to motor vehicle accidents had more severe injuries than those in an urban city.