Road traffic injuries caused by motorcycle crashes are one of the major public health burdens leading to high mortality, functional disability, and high medical costs. The helmet is crucial protective equipment for motorcyclists. This study aimed to measure the protective effect of motorcycle helmets on clinical outcomes and to compare the effects of high- and low-speed motorcycle crashes.

A cross-sectional observational study was conducted using a nationwide registry of severe trauma patients treated by emergency medical services (EMS) providers in Korea. The study population consisted of severe trauma patients injured in motorcycle crashes between January and December 2013. The primary and secondary outcomes were intracranial injury and in-hospital mortality. We calculated adjusted odds ratios (AORs) of helmet use and motorcycle speeds for study outcomes after adjusting for potential confounders.

Among 495 eligible patients, 105 (21.2%) patients were wearing helmets at the time of the crash, and 256 (51.7%) patients had intracranial injuries. The helmeted group was less likely to have an intracranial injury compared with the un-helmeted group (41.0% vs. 54.6%, AOR: 0.53 (0.33–0.84)). However, there was no significant difference in in-hospital mortality between the two groups (16.2% vs. 16.9%, AOR: 0.91 (0.49–1.69)). In the interaction analysis, there was a significant preventive effect of motorcycle helmet use on intracranial injury when the speed of the motorcycle was <30km/h (AOR: 0.50 (0.27–0.91)).

Wearing helmets for severe trauma patients in motorcycle crashes reduced intracranial injuries. The preventive effect on intracranial injury was significant in low-speed motorcycle crashes.