Comparison of single bicycle crashes and collisions among severely injured cyclists-A 16-year analysis based on the Helsinki Trauma Registry (HTR)

Objective: The Finnish national Traffic Safety Strategy 2022-2026 seeks to halve the number of road fatalities and serious injuries from 2020 to 2030. The strategy states that better information on bicycle crashes is needed for safety promotion. The aim of this study was to describe the demographics, injury characteristics, alcohol involvement, and helmet use of severely injured cyclists and to compare single bicycle crashes (falling alone or hitting a fixed object) to collisions. Material and methods: We identified all bicycle crashes between 2006 and 2021 from the Helsinki Trauma Registry (HTR). Variables analysed were basic patient demographics, Abbreviated Injury Scale (AIS) codes, AIS 3+ injuries, injured body regions, patient Injury Severity Score (ISS) and New Injury Severity Score (NISS), 30-day in-hospital mortality, ICU length of stay, injury mechanism, alcohol use by the injured cyclists, and helmet use. Results: Of the 325 severe (NISS >15) cycling injury patients in the HTR, 53.5 % were injured in single crashes and 46.5 % in collisions with a moving object. Most (71.4 %) patients were men and mean age of all patients was 54.1 years (SD 16.7). Alcohol was detected in 23.1 % of cases and more often in single crashes (32.8 %) than in collisions (11.9 %). Less than a third (29.2 %) of all cyclists wore a helmet; those who wore a helmet had fewer serious (AIS 3+) head injuries than those who did not. Cyclists injured in collisions had higher ISS and NISS scores than those injured in single crashes. Serious (AIS 3+) injuries in extremities or in pelvic girdle were more common in collisions than in single crashes. Conclusions: Among severely injured cyclists, single bicycle crashes were more common; alcohol was more often detected in single bicycle crashes than in collisions. Overall injury severity was higher in collisions than in single crashes. Helmet users had less AIS 3+ head injuries than non-users. Attention should be focused on preventing alcohol-related cycling injuries, promoting use of bicycle helmets, and more precise and comprehensive documentation of bicycle crashes in health care units.