After Michigan repealed its helmet law, motorcycle riders who crashed there were 24 percent less likely to be wearing protective head gear and 14 percent more likely to suffer a head injury, a new study found.
The first statewide investigation since Michigan loosened its law in 2012 also showed a shift in the severity of head injuries diagnosed in emergency rooms, with more skull fractures and fewer mild concussions after the state allowed most bikers to ride without helmets.
"As an emergency physician and a public health researcher, I worry that the law (change) had a negative impact on the health and wellbeing of the people of Michigan, and I think that the data bears that out," study lead author Dr. Patrick Carter said in a phone interview.
"Policymakers need to decide whether the effects of this type of law change are what they want to see," said Carter, who is a professor of emergency medicine at the University of Michigan in Ann Arbor.
Dr. Jayson Aydelotte, a trauma surgeon at Ascension's Seton Healthcare Family and University Medical Center Brackenridge in Austin, Texas, views compulsory helmets as analogous to seatbelts.
"It's like when we first started wearing seatbelts. It's not a burden, at least it wasn't for me," he said in a phone interview. Aydelotte, who wasn't involved in the new research, rode motorcycles for about a decade but stopped when he decided it was too dangerous, even with a helmet.
Carter and his colleagues compared rates of helmet use, deaths and head injuries for one year before and after Michigan lifted its helmet law for riders age 21 and older who pass a safety course and carry $20,000 in medical insurance.
Lawmakers promoted the repeal partly in an effort to increase motorcycle tourism into Michigan. But the study showed no uptick in the number of out-of-state motorcyclists involved in accidents, leading Carter to believe the helmet repeal failed to boost the number of visitors, he said.
Ironically, a sponsor of the legislation who promoted it as a tourism draw, state Representative Peter Pettalia, R-Presque Isle, died in a motorcycle crash in September.
The 61-year-old former emergency medical technician had bemoaned the fact that Michigan was surrounded by states that allow bikers to ride without headgear. He was wearing a helmet when a truck hit him.
Carter's team analyzed 7,235 police-reported accidents as well as 1,094 reports of head injuries among patients hospitalized at trauma centers.
Though prior studies found that repeals of helmet laws increased the number of motorcycle accident deaths, the new study showed no increase in fatalities, as reported in the American Journal of Public Health.
But it did find that bikers without helmets were nearly twice as likely to die in a crash compared to helmeted riders, and three times as likely to suffer a head injury.
Intoxicated riders appear to be the most vulnerable. Their helmet use dropped 35 percent in one data set and 47 percent in another.
"Drinkers were the population most likely to take off their helmets (after the law was repealed), and they already are in a high-risk pool if they're going to ride intoxicated," Carter said.
Aydelotte believes that statewide death rates from motorcycle accidents likely will rise after the one-year period Carter and his team studied.
Head injuries are the leading cause of motorcycle accident deaths, according to the authors. They say motorcyclists died in 14 percent of U.S. traffic fatalities in 2014, although only 3 percent of registered vehicles were motorcycles.
Prior research has found that helmets cut head-injury risk by more than two-thirds, according to the study.
Three states have no helmet requirements; 28 states require some riders to wear helmets; and 19 states and the District of Columbia require all motorcyclists to wear them.
A previous study of one Michigan hospital found that deaths and head injuries rose sharply among bikers treated at one hospital in the three years following repeal of the helmet law.
Deaths at the crash scene more than quadrupled, and deaths in the hospital tripled, the American Journal of Surgery study found.