A 6-year survey of road traffic accidents in Southwest China: Emphasis on traumatic brain injury

Abstract Background: In-depth investigation of road traffic accidents (RTAs) provides valuable data for implementing effective interventions to reduce traffic injury-related mortality. The objective of this study is to provide an overview of the patterns of injuries, especially traumatic brain injury (TBI) caused by RTAs and to discuss some of the public health consequences. Methods: A scientific team was established to collect cases of road traffic accidents occurring between 2013 and 2018 in Chongqing, Southwest China. For each accident, literature from local police departments, post-mortem reports, and clinical records were studied to determine the environment-, vehicle-, and person- variables. Head injuries were coded according to the abbreviated injury scale (AIS) 2005 revision. The overall injury distribution and TBI patterns of four types of road users (driver, passenger, motorcyclist, and pedestrian) were compared using univariate statistical methods. The environmental and time distribution of accidents with AIS1 + brain injuries were shown by bar and pie chart. The risks of severe brain injury, whether the motorcyclist was wearing a helmet or not, were compared, and the risk factors of severe TBI in pedestrian were determined by odds ratio analysis. Results: This study enrolled 2,131 accidents with 2,741 persons of all kinds of traffic participants, 1,149 of them suffered AIS1 + head injury and 1,598 (58%) died within 7 days of the collision. The most common cause of deaths is due to head injury with 714 (85%) and 1,266 (79%) persons dying within 2 hours after the collision. Out of the 1,149 persons who suffered TBI, the male/female ratio was 2.2:1 and the median age was 49 years. The pedestrian was the oldest group with a median age of 62 years. Specifically, temporal (31%) and subarachnoid hemorrhage (61%) was the most common injury pattern. Among 423 persons who suffered both skull fracture and intracranial injury, 102 (24.1%) suffered intracranial injury but no skull fractures, while no skull fracture without intracranial injury was found. Besides, motorcyclists without a helmet were at higher risks than those with helmet for all the brain injury categories. The risk of pedestrian suffering severe TBI at an impact speed of more than 70 km/h is 100 times higher than that with an impact speed of less than 40 km/h. No significant difference was found in the incidence of the cause of deaths, skull fracture, and intracranial hemorrhage among four types of road users. Conclusion: Head injury still occupied the highest proportion among the injuries and deaths associated with RTAs. There is an urgent need to develop a more reliable brain injury evaluation criterion for better protection of road users. We believe that strengthening the emergency care to head injury at the scene is the most effective way to reduce traffic fatality.