Effect of Age on Severity of Injuries in Traffic Accidents Involving Elderly Drivers

Background: The number of elderly drivers involves in traffic accidents is increasing with the aging of the population. This study aimed to investigate the relationship between the driver's age and injury severity in traffic accidents caused by elderly drivers. Methods: Data from the Emergency Department-based Injury In-depth Surveillance (EDIIS) from 2011-2016 was used to analyze traffic accidents by drivers aged 60 and older. Patients were classified into non-severe and severe injury group. The driver's age was subdivided by 5-year interval to compare the difference in age groups. Multivariate logistic regression was used to identify the factors related to the severe injury. Results: Among a total of 262,361 subjects, 6,427 patients were included, of which 890 (13.9%) were severely injured. There were more male in all age groups. The accidents occurred most in the daytime and general roads. In multivariate analysis, drivers aged 75-79 had 1.39 odds ratio (OR) of severe injury compared to drivers aged 60-64 (95% confidence interval [CI]: 1.06-1.84). Male (OR: 1.71, 95% CI: 1.40-2.09), alcohol intake (OR: 2.02, 95% CI: 1.39-2.94), and non-use of seatbelt (OR: 2.06, 95% CI: 1.71-2.48) were associated with severe injury, as well as the counterpart and road class. Conclusion: Among elderly drivers, there were significant differences in characteristics of traffic accidents according to age groups. The risk of severe injury increased in drivers aged over 75 years comparing to relatively young elderly drivers. These results provide the practical adjustment in determining the age standard when establishing traffic safety policies.