title: Repeal of the Michigan helmet law: the evolving clinical impact.
abstract: BACKGROUND
  Michigan repealed a 35-year mandatory helmet law in April 2012. We examined the impact of this legislation on a level 1 trauma center.
  
  
  METHODS
  A retrospective cohort study comparing the 7-month period before and the 3 motorcycle seasons after the helmet law repeal.
  
  
  RESULTS
  A total of 345 patients were included in the study. Nonhelmeted riders increased from 7% to 28% after the repeal. Nonhelmeted crash scene fatalities were higher after the repeal (14% vs 68%). The nonhelmeted cohort had significantly higher in-patient mortality (10% vs 3%), injury severity score (19 vs 14.5) and abbreviated injury scale head (2.2 vs 1.3). Non-helmeted riders also had increased alcohol use, intensive care unit length of stay and need for mechanical ventilation. The median hospital cost for the non-helmeted cohort was higher (P < .05).
  
  
  CONCLUSIONS
  The impact of the Michigan helmet law repeal continues to evolve. Three years after this legislative change, we are now observing increased injury severity score, higher in-patient mortality, and worse neurologic injury.
authors.affiliation: Department of Surgery, Michigan State University and Grand Rapids Medical Education Partners, 221 Michigan Street 200A, Grand Rapids, MI 49503, USA. Electronic address: becky.striker@grmep.com.
authors.forename: Rebecca H
authors.initials: RH
authors.lastname: Striker
authors.affiliation: Department of Surgery, Michigan State University and Grand Rapids Medical Education Partners, 221 Michigan Street 200A, Grand Rapids, MI 49503, USA.
authors.forename: Alistair J
authors.initials: AJ
authors.lastname: Chapman
authors.affiliation: Department of Surgery, Michigan State University and Grand Rapids Medical Education Partners, 221 Michigan Street 200A, Grand Rapids, MI 49503, USA.
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Titus
authors.affiliation: Department of General Surgery, Michigan State University, Grand Rapids, MI, USA; Grand Rapids Medical Education Partners Research Department, Grand Rapids, MI, USA.
authors.forename: Alan T
authors.initials: AT
authors.lastname: Davis
authors.affiliation: Department of Surgery, Michigan State University and Grand Rapids Medical Education Partners, 221 Michigan Street 200A, Grand Rapids, MI 49503, USA; Department of General Surgery, Michigan State University, Grand Rapids, MI, USA; Department of Trauma Surgery, Spectrum Health, Grand Rapids, MI, USA.
authors.forename: Carlos H
authors.initials: CH
authors.lastname: Rodriguez
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000453:epidemiology; D006259:Craniocerebral Trauma / Q000209:etiology* / Q000401:mortality / Q000517:prevention & control*; D005260:Female; D006260:Head Protective Devices / Q000706:statistics & numerical data*; D006801:Humans; D015601:Injury Severity Score; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008824:Michigan / Q000453:epidemiology; D008875:Middle Aged; D009049:Motorcycles / Q000331:legislation & jurisprudence*; D012121:Respiration, Artificial / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012307:Risk Factors
keywords: Helmet; Helmet law; Michigan; Mortality; Motorcycle; Repeal