Examining the Impact of Mandatory Helmet Laws on Traumatic Brain Injury and Mortality

Background:  The leading cause of death among children and young adults in the United States is Traumatic Brain Injury (TBI).  Unintentional injuries, including TBI, are the 5th leading cause of death among all age groups.(CDC, 2010)   It is likely that people who do not wear helmets and ride motorized vehicles would have significantly more severe injuries than those who do not.  However, until recently data on emergency department visits were not readily available on a national level to the independent academic researcher.  More lenient regulations regarding release of the de-identified data are now in place and permit such analysis.  Laws governing helmet use vary by state.  Nineteen states and the District of Columbia require all motorcyclists to wear a helmet.  In 28 states, helmet requirements vary by age of the rider, season of the year, type of vehicle, etc.  Illinois, Iowa, and New Hampshire are currently the only states in the United States that do not require the use of helmets.

Methods:  This exploratory study employs data distributed by the Agency for Healthcare Research and Quality via the Healthcare Cost and Utilization Project to evaluate the effectiveness of mandatory helmet laws in reducing motorcycle accident mortality and traumatic brain injury.  These include the 2012 Nationwide Emergency Discharge Sample (NEDS) which aggregates state level data and provides a 20% sample of all emergency department admissions.  State level information were analyzed using HCUP-Net.  Two of the states that have no helmet requirements, IL and IA, cooperate with HCUP-Net.  In addition, the 2011 Nationwide Inpatient Sample also provided state level comparisons.

Results:  More complete analysis is in process, but it is clear that states that had no motorcycle helmet requirements had higher rates of motorcycle related mortality and increased severity of motorcycle related traumatic brain injury.  In addition, those states also had higher medical costs and longer length of hospital stays for individuals who did survive a motorcycle accident.  

Conclusions:  Mandatory helmet laws do improve rates of traumatic brain injury and motorcyle accident mortality. Analysis is limited by fact that the Nationwide Emergency Department sample is stratified by geographic region and does not provide state specific data.  The decision to eliminate state level identifiers from the National Inpatient Sample protects the confidentiality of hospitals and patients, but reduces the ability to use the data for comparisons of state level policy.