Trends and characteristics of severe road traffic injuries in children: a nationwide cohort study in Japan.

Purpose: The purpose of this study was to evaluate temporal trends of characteristics of severe road traffic injuries in children and identify factors associated with mortality using a nationwide database in Japan.

Methods: We performed a retrospective analysis of Japan Trauma Data Bank (JTDB) from 2004 to 2018. We included patients with traffic injuries under the age of 18 who were hospitalized. The primary outcome was in-hospital mortality. We evaluated trends in characteristics and assessed factors associated with in-hospital mortality using a logistic regression analysis.

Results: A total of 4706 patients were analyzed. The most common mechanism of injury was bicycle crash (34.4%), followed by pedestrian (28.3%), and motorcycle crash (21.3%). The overall in-hospital mortality was 11.2%. We found decreasing trends in motorcycle crash and in-hospital mortality and increasing trends in rear passenger seats in cars over the 15-year period. The following factors were associated with in-hospital mortality: car crash (aOR 1.69, 95%CI 1.18-2.40), pedestrian (aOR 1.50, 95%CI 1.13-1.99), motorcycle crash (aOR 1.42, 95%CI 1.03-1.95) [bicycle crash as a reference]; concomitant injuries to head/neck (aOR 5.06, 95%CI 3.81-6.79), thorax (aOR 2.34, 95%CI 1.92-2.87), abdomen (aOR 1.74, 95%CI 1.29-2.33), pelvis/lower-extremity (aOR 1.57, 95%CI 1.23-2.00), spine (aOR 3.01, 95%CI 2.02-4.43); and 5-year increase in time period (aOR 0.80, 95%CI 0.70-0.91).

Conclusions: We found decreasing trends in motorcycle crash and in-hospital mortality, increasing trends in rear passenger seats in cars over the 15-year period, and factors associated with in-hospital mortality such as type of mechanisms and concomitant injuries. Strengthening child road safety measures, particularly for rear passenger seats in vehicles, is imperative to enhance our dedication to injury prevention.