Bicycle-related Crashes in Hong Kong: Is It Possible to Reduce Mortality and Severe Injury in the Metropolitan Area?

TLDR: Middle-aged casualties, the presence of head injuries, and the involvement of motor vehicles all increase the risk of more severe injury in bicycle-related crashes.

Abstract: Background: Cycling is not the primary mode of commuter transport in Hong Kong, yet cyclists are exposed to a high risk of injury and fatality in road crashes. It is essential to identify the significant factors contributing to severe injury among cyclists in Hong Kong. Aim: To evaluate the effects of significant factors, including demographics, temporal distribution, cyclist behavior, road conditions, and weather, on the risk of severe and life-threatening injury among cyclists in road crashes in Hong Kong. Method: The study was nested on a database known as Road Casualty Information System (RoCIS) which is a linked database between police traffic accident investigations reports and hospital injury records. A total of 682 victims were identified during the study period from 1 January 2004 to 31 December 2006. In particular, injured body part, demographics, helmet use, alcohol intoxication, weather conditions, road type and geometry, and collision characteristics of 682 trauma patients were the attributing variables of concern. The primary outcome measure was the injury severity of trauma patients which was classified into three levels: slight injury [Injury severity Scale (ISS) =9), and life-threatening injury (ISS >=25). A multinomial logit regression model was established to evaluate the significance of factors contributing to severe and lifethreatening injuries among cyclists in road crashes. Results: The results indicated that middle-aged and elderly (35-54, RRR=2.48; and 55 or above, RRR=4.39) casualties and favourable weather conditions (2.56) significantly increased the risk of severe injury among cyclists. The presence of severe head injury (RRR=509.24), severe trunk injury (RRR=79.24), and the involvement of motor vehicles (RRR=27.18) substantially increased the risk of life-threatening injury to cyclists. Conclusions: Middle-aged casualties, the presence of head injuries, and the involvement of motor vehicles all increase the risk of more severe injury in bicycle-related crashes. Safety education and countermeasures should target at middle-aged and elderly cyclists and discourage cycling on the motorway.