title: The impact of helmet use on outcomes after a motorcycle crash.
abstract: BACKGROUND
  Helmet use in a motorcycle collision has been shown to reduce head injury and death. Its protective effect on the cervical spine (C-spine), however, remains unclear. The objective of this study was to explore the relationship between helmet use and C-spine injuries.
  
  
  METHODS
  Retrospective National Trauma Data Bank (NTDB) study. All motorcycle collisions between 2007 and 2014 involving either a driver or passenger were included. Data collected included demographics, vital signs, Abbreviated Injury Scale (AIS), Injury Severity Score (ISS) and specific injuries. The primary outcome was the prevalence of C-spine injuries. Secondary outcomes included were overall mortality, ventilation days, intensive care unit length of stay (LOS), total hospital LOS, and in-hospital complications.
  
  
  RESULTS
  A total of 270,525 patients were included. Helmets were worn by 57.6% of motorcyclists. The non-helmeted group was found to have a higher incidence of head injury with head AIS>2 (27.6% vs 14.8%, p<0.001). Univariate analysis showed a higher prevalence of C-spine injuries in the non-helmeted group (10.4% vs 9.4%, p<0.001), with a higher proportion of severe C-spine injuries with AIS>2 (3.2% vs 2.6%, p<0.001). Additionally, traumatic brain injury (TBI) was found to be two times higher in the non-helmeted group (20.7% vs 10.9%, p<0.001). Multiple logistic regression showed helmet use to be an independent protective factor against mortality (OR=0.832, 95% CI 0.781-0.887, p<0.001). Although statistically significant in univariate analysis, helmet use was not associated with C-spine injuries after adjusting for relevant covariates. However, helmet use reduced the risk of severe head injuries by almost 50% (OR=0.488, 95% CI 0.475-0.500, p<0.001).
  
  
  CONCLUSIONS
  Helmet use reduces the risk of head injury and death among motorcyclists; however, no association with C-spine injuries could be detected.
authors.affiliation: Division of Acute Care Surgery and Surgical Critical Care, LAC+USC Medical Center, CA, USA.
authors.forename: Desmond
authors.initials: D
authors.lastname: Khor
authors.affiliation: Division of Acute Care Surgery and Surgical Critical Care, LAC+USC Medical Center, CA, USA. Electronic address: kenji.inaba@med.usc.edu.
authors.forename: Kenji
authors.initials: K
authors.lastname: Inaba
authors.affiliation: Division of Acute Care Surgery and Surgical Critical Care, LAC+USC Medical Center, CA, USA.
authors.forename: Alberto
authors.initials: A
authors.lastname: Aiolfi
authors.affiliation: Division of Acute Care Surgery and Surgical Critical Care, LAC+USC Medical Center, CA, USA.
authors.forename: Samantha
authors.initials: S
authors.lastname: Delapena
authors.affiliation: Division of Acute Care Surgery and Surgical Critical Care, LAC+USC Medical Center, CA, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Benjamin
authors.affiliation: Division of Acute Care Surgery and Surgical Critical Care, LAC+USC Medical Center, CA, USA.
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Matsushima
authors.affiliation: Division of Acute Care Surgery and Surgical Critical Care, LAC+USC Medical Center, CA, USA.
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Strumwasser
authors.affiliation: Division of Acute Care Surgery and Surgical Critical Care, LAC+USC Medical Center, CA, USA.
authors.forename: Demetrios
authors.initials: D
authors.lastname: Demetriades
mesh_terms: D015998:Abbreviated Injury Scale; D000063:Accidents, Traffic / Q000401:mortality / Q000706:statistics & numerical data; D000293:Adolescent; D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae / Q000293:injuries*; D006259:Craniocerebral Trauma / Q000453:epidemiology* / Q000401:mortality / Q000517:prevention & control; D003422:Critical Care / Q000706:statistics & numerical data; D016208:Databases, Factual; D005260:Female; D006260:Head Protective Devices / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D015601:Injury Severity Score; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009049:Motorcycles; D019838:Neck Injuries / Q000453:epidemiology* / Q000401:mortality; D012189:Retrospective Studies; D013124:Spinal Injuries / Q000453:epidemiology* / Q000401:mortality; D014481:United States / Q000453:epidemiology; D055815:Young Adult
keywords: Cervical spine; Helmet; Motorcycle collisions; Motorcyclist; Trauma