Bike-shares linked with greater risk of head injury
Editor's note: The headline and story have been corrected and clarified to convey that the study's measure was the proportion of head injuries among all bicycle-related injuries in the cities studied. Additionally, the original version of this news release did not identify the limitations of the research, as outlined on pages 4 and 5 of the study published online. The researchers were not able to determine whether injured people represented by the data were using bike shares, nor whether they were wearing helmets. - June 18, 2014
Risk that a bicycle-related injury involved a head injury increased 14 percent after implementation of bike-share programs in several major cities, according to a new study from the University of Washington and Washington State University.
The study, titled “Public Bicycle Share Programs and Head Injuries,” was published online June 12 in the American Journal of Public Health.
Researchers looked at the change in the proportion of bicycle-related head injuries before and after the implementation of bike-share programs in five cities in the United States and Canada. They also gathered similar data for five cities that did not have bike-share programs.
Of all bicycle-related injuries that occurred in bike-share cities during the study period, the proportion that were head injuries rose from 42 percent to 50 percent after bike-share program implementation. No such increase was found in cities without these programs.
“Our results suggest that bike-share programs should place greater importance on providing helmets so riders can reap the health benefits of cycling without putting themselves at greater risk for injury,” said Janessa Graves, affiliate faculty at the Harborview Injury Prevention and Research Center and assistant professor at the Washington State University College of Nursing.
She led the study; Frederick Rivara, a UW professor of pediatrics, was senior author.
Helmets are regularly shown to help lower the risk of head and brain injury, whereas not using a helmet can increase fatality among people who incur a traumatic brain injury in a biking accident. Despite these findings, many bike-share programs worldwide do not offer helmets to cyclists.
Graves and her colleagues examined trauma-registry data for bicycle-related injuries for two years before and one year after bike programs began. They studied the same timeframe in control cities. They collected injury data from trauma center databases and registries in the United States and Canada.
The cities with bike-share programs were Boston, Miami Beach, Minneapolis, Washington, D.C., and Montreal, Quebec. None of the programs provided helmets to users during the study period. The cities without bike-share programs were Los Angeles, Milwaukee, New York City, Seattle and Vancouver, British Columbia.
In September, Seattle will implement a bike-share program called Pronto Cycle Share, one of the first such programs in the United States to offer helmet rentals. Each helmet will cost $2 and be sanitized after each use. Providing helmets in Seattle is essential due to King County’s bike helmet regulation law. WSU has its own bike-share program in Pullman called Green Bike, which also offers helmets.
“It doesn’t take much effort to wear a helmet when you bike,” Graves said, “but doing so could make all the difference.”
The study was supported by the National Institute of Child Health and Human Development under award number T32HD057822.