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Member Research & Reports

Member Research & Reports

Kentucky Researcher Examines Protective Effects of Motorcycle Helmets Using Linked Police Accident Report and Hospital Billing Records

Dr. Michael D. Singleton, Assistant Professor of Biostatistics, Department of Biostatistics and Kentucky Injury Prevention and Research Center, University of Kentucky College of Public Health, published new research on the protective effects of motorcycle helmets in the journal Traffic Injury Prevention. The article, “Differential protective effects of motorcycle helmets against head injury,” was published online on September 2, 2016.


[Photo: Dr. Michael D. Singleton]

Although numerous observational studies have demonstrated a protective effect of motorcycle helmets against head injury, the degree of protection against specific head injury types remains unclear. Experimental biomechanics studies involving cadavers, animals and computer models have established that head injuries have varying etiologies. Singleton conducted a retrospective cross-sectional study comparing helmet protection against skull fracture, cerebral contusion, intracranial hemorrhage and cerebral concussion in a consecutive series of motorcycle operators involved in recent traffic crashes in Kentucky.

Anonymized police collision reports and hospital inpatient and emergency department (ED) billing claims were probabilistically linked and analyzed for the period 2008 to 2012. Motorcycle operators with known helmet use who were not killed at the crash scene were included in the study. Helmet use was ascertained from the police report. Skull fracture, cerebral contusion, intracranial hemorrhage and cerebral concussion were identified from ICD-9-CM codes on the claims records. The relative risks of each type of head injury for helmeted versus unprotected operators were estimated using generalized estimating equations.

The study found that motorcycle helmets were associated with a 69 percent reduction in skull fractures, 71 percent reduction in cerebral contusion, and 53 percent reduction in intracranial hemorrhage. There was also a 20 percent reduction in cerebral concussion, though this result was not statistically significant. The author concludes that that current motorcycle helmets do not protect equally against all types of head injury, and suggests that efforts to improve rotational acceleration management in motorcycle helmets should be considered.

Dr. David Pienkowski, Associate Professor of Biomedical Engineering, at the University of Kentucky, provided valuable input on the biomechanics of motorcycle helmets and head injury. This research was partially funded by the National Highway Traffic Safety Administration, cooperative agreement number DTNH22-08-H-00302 (Crash Outcome Data Evaluation System).