WASHINGTON – Mandatory bicycle helmet laws are associated with a lower incidence of fatalities among youth cyclists involved in motor vehicle collisions, a national analysis has shown.
States with laws that require bicyclists to wear helmets had only 84% of the deaths per population that those without helmet laws had, after adjustment for other potential confounding factors, Dr. William P. Meehan III reported at the annual meeting of the Pediatric Academic Societies.
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Mandatory bicycle helmet laws are associated with a lower incidence of fatalities among youth cyclists involved in motor vehicle collisions, a national analysis has shown.
"Twenty-nine states still do not have [laws requiring cyclists to wear helmets], and we think they should be considered," said Dr. Meehan, director of the Micheli Center for Sports Injury Prevention and the Sports Concussion Clinic in the division of sports medicine at Boston Children’s Hospital.
Approximately 900 people die each year in bicycle crashes, three-quarters of them from traumatic brain injuries. On a local level, previous studies have shown that the laws result in increased helmet usage and decreased risk of injury and death in bicycle–motor vehicle collisions.
To assess the effect nationally, Dr. Meehan and his colleagues analyzed data on U.S. bicyclists younger than 16 years of age who died between January 1999 and December 2009. They used the Fatality Analysis Reporting System (FARS) to compare death rates in states with and without mandatory helmet laws. FARS is run by the National Highway Traffic Safety Administration and collects data on all motor vehicle accidents that result in the death of someone involved in a collision.
Over the study period, 1,612 bicyclists under the age of 16 died in a collision with a motor vehicle. The mean unadjusted rate of fatalities was 2 per million in states with helmet laws, versus 2.5 per million in states without the laws. The overall unadjusted incidence rate ratio was 0.83.
After adjustment for three factors that could potentially influence the rate of fatality in bicycle–motor vehicle collisions – elderly driver licensure laws, legal blood alcohol limits (lower than .08% versus .08% or higher), and household income, states with mandatory helmet laws continued to be associated with lower rates of fatalities, with an adjusted incidence rate ratio of 0.84, reported Dr. Meehan, also of the department of pediatrics at Harvard Medical School, Boston.
Because the FARS database includes only collisions that resulted in fatalities – and not other severe injuries – there’s "potentially much greater benefit in helmet legislation" than is reflected by the study findings, he noted.
The American Academy of Pediatrics supports legislation that requires all cyclists to use helmets.
State laws requiring the use of bicycle helmets cover populations up to varying ages, but almost all cover children up to 16 years of age.
At the start of the study period, 16 states had bicycle helmet laws. By the end, in 2009, 19 states and the District of Columbia had helmet laws. (At least two of the additional laws were enacted in the earlier part of the study period). Helmet mandates have also been established by some local municipalities throughout the country, but the analysis covered only states.
The study was funded in part by the Micheli Center for Sports Injury Prevention and the National Institutes of Health. Dr. Meehan reported that he had no relevant financial disclosures.