Universal helmet laws reduce traumatic brain injuries in young motorcyclists, according to trauma surgeons

It is already known that mandatory helmet use laws save lives and reduce the number of traumatic head injuries in adults. However, in a first-of-its-kind study, researchers compared the impact of partial helmet use laws -- state legislation that requires only riders under age 18 or those under age 21 to wear a helmet -- to universal helmet use laws on the number of traumatic head injuries in young people.

"TBI is the biggest burden in trauma care, so we wanted to see whether having universal helmet laws versus age-specific helmet laws really made a difference in the younger population," said contributing study author Bellal Joseph, MD, FACS, a trauma surgeon and associate professor of surgery at the University of Arizona, Tucson.

Today there are more motorcyclists on the road than ever before. But only 19 states plus the District of Columbia require all motorcyclists of any age to wear a helmet. Notably, the highest death and injury rates among motorcyclists are in 20 to 24 year olds. Wearing a motorcycle helmet is one way to reduce traumatic head injuries and deaths from crashes.

"We know from research that helmet use is significantly greater in states with universal laws compared to those with age-limited laws or no laws at all," said lead study author K. Tinsley Anderson, MD, a general surgery resident at the University of Arizona, Tucson. "What we also find is that having an age-limited law is the same as having no law at all. The rates of helmet usage in those states are the same as not having a law at all."

For the study, researchers used the Nationwide Inpatient Sample (NIS) database, which is derived from 20 percent of all admissions and discharges of US hospitals. They looked at all patients under 21 with trauma-related hospitalizations in 2011. The aim was to assess the impact of helmet legislation on the incidence of motorcycle accident-related TBI. The primary outcome was incidence of TBI, and secondarily death from TBI.

Patients included in the study were motorcycle riders -- passengers or drivers -- who had been in an accident and were admitted to a hospital for TBI. A total of 1,165,150 patients with trauma-related hospitalization across 39 states were reviewed. Of those, 598 patients with motorcycle accidents were identified. States were classified into three groups based on helmet legislation: universal helmet legislation, less than 18-years helmet legislation and less than 21-years helmet legislation.

The researchers found that the incidence of TBI was significantly less in states with universal helmet laws compared to states with age-restricted helmet laws. In states with universal helmet laws, the rate of TBIs per 1,000 motorcycle accidents was 282 versus 307 in states with less than 18-years helmet legislation and 366 in states with less than 21-years helmet legislation.

Further, the overall mortality from TBI was significantly less in those states with universal helmet legislation. When study authors controlled for all injuries together, they found that young riders in states with universal helmet use laws were 2.5 times less likely to sustain a traumatic head injury.

"Our study is unique because we prove that universal helmet laws save lives and decrease TBIs in the pediatric population as well," Dr. Anderson said. "I think it's an important group to look at because they are the least risk averse group and most inexperienced rider population and are more likely to be unprotected in the absence of universal laws."

Dr. Joseph adds, "I think just having this kind of information may also help patients and the public take a different perspective, even where the laws don't exist."