Epidemiology of Bicycle Accidents in a Japanese Core Regional City: Characteristics of Single- and Multiple-Rider Bicycle Accidents

Abstract Introduction: Comprehensive epidemiological studies of bicycle accidents involving all ages in Japan are limited, particularly regarding multiple-rider incidents. This study investigated the epidemiology of single- and multiple-rider bicycle accidents in a Japanese core regional city. Method Ambulance transport data from Takatsuki City (January 1, 2014 to July 31, 2024) were retrospectively analyzed, including demographics, accident characteristics, and severity of injury for bicycle accident patients. The primary outcome was examination of the epidemiology of bicycle accidents with moderate or greater severity or severe or greater severity, encompassing both single- and multiple-rider incidents. Statistical tests and logistic regression analysis were used. Result For 6,683 transported patients, 6377 (95.4%) involved single-rider accidents and 306 (4.6%) involved multiple riders. Single-rider patients were older and more often male. Moderate or greater injuries occurred in 625 single-rider and 11 multiple-rider patients. No severe or fatal injuries occurred in multiple-rider accidents. General roadways and intersections were common accident locations. Male sex and older age predicted greater injury severity in single-rider accidents. Fifty single-rider bicycle accidents resulted in severe or greater severity injuries, and 4 fatal accidents were recorded. Conclusion This study uniquely details multiple-rider bicycle accidents in Japan, revealing a lower severity of injuries compared to single-rider accidents.