Background: This study aimed to investigate differences in injury severity and mortality between patients who met with bicycle or motorcycle accidents and were hospitalized at a Level I trauma center in Taiwan.
Methods: We performed a retrospective analysis of bicycle-related injuries that have been reported in the Trauma Registry System in order to identify and compare 699 bicyclists to 7,300 motorcyclists who were hospitalized for treatment between January 1, 2009 and December 31, 2013. Statistical analyses of the injury severity, associated complications, and length of stay in the hospital and intensive care unit (ICU) were performed to compare the risk of injury of bicyclists to that of motorcyclists with the corresponding unadjusted odds ratios and 95 % confidence intervals (CIs). Adjusted odds ratios (AORs) and 95 % CIs for mortality were calculated by controlling for confounding variables that included age, and an Injury Severity Score (ISS) was calculated.
Results: More of the cyclists were under 19 years of age or over 70 than were the motorcyclists. In contrast, fewer bicyclists than motorcyclists wore helmets, arrived at the emergency department between 11 p.m. and 7 a.m., and had a positive blood alcohol concentration test. The bicyclists sustained significantly higher rates of injuries to the extremities, while motorcyclists sustained significantly higher rates of injuries to the head and neck, face, and thorax. Compared to motorcyclists, the bicyclists had significantly lower ISSs and New Injury Severity Scores, shorter length hospital stays, and a smaller proportion of admittance into the ICU. However, the bicyclists had higher AORs for in-hospital mortality (AOR: 1.2, 95 % CI: 1.16-1.20). In terms of critical injury severity (ISS ≥ 25), the bicyclists had 4.4 times (95 % CI: 1.95-9.82) the odds of mortality than motorcyclists with the same ISSs.
Conclusions: Data analysis indicated that the bicyclists had unique injury characteristics including bodily injury patterns and lower ISSs, but had higher in-hospital mortality compared to motorcycle riders. In this study, given that only 9 % of bicyclists reported wearing helmets and considering the high mortality associated with head injury, it is possible that some bicycle riders underestimated the gravity of cycling accidents.