Objective To assess the direct economic burden and influencing factors of road traffic injuries in Shanghai， providing a basis for future prevention of road traffic injuries.

Methods Information of inpatient cases caused by road traffic injuries was collected from 22 pilot hospitals in Shanghai that participated in the registration and reporting system of injury hospitalizations from 2017 to 2020. The main content of the collected information included basic demographic information， total hospitalization costs for injuries， mode of transportation， cause of injury， nature of injury， location of injury， and hospital level. Univariate analysis was used to analyze the average hospitalization costs and length of hospital stay between different years. Kruskal-Wallis test was used to analyze the median hospitalization costs and the median length of hospital stay between different years， and the median hospitalization costs of different groups. A full subset regression model in multivariate regression was used to explore the main influencing factors of hospitalization costs.

Results A total of 4 655 patients were hospitalized with road traffic injuries， including 2 675 males （57.47%） and 1 980 females （42.53%）. The average age was （53.84±15.37） years old， with a minimum age of 4 years old and a maximum age of 97 years old. 1 907 patients （40.97%） had non-motor vehicle accidents， and 2 748 patients （59.03%） had motor vehicle accidents. The average hospitalization cost is 23 245.71 yuan， with a median of 9 793.94 yuan. The average length of stay was 13.61 days， with a median stay of 10.00 days. The main factors affecting hospitalization costs included year， nature of injury， location of injury， length of hospital stay， and hospital level.

Conclusion Road traffic injuries seriously affect the health of middle-aged and young people， especially vulnerable road user such as pedestrians and cyclists， causing serious injury and an increase of direct economic burden year by year. Therefore， road traffic injury prevention projects should be actively carried out to reduce the occurrence of injuries.