Interesting new paper in Health Economics. “Effects of Bicycle Helmet Laws on Children’s Injuries“:
Cycling is popular among children, but results in thousands of injuries annually. In recent years, many states and localities have enacted bicycle helmet laws. We examine direct and indirect effects of these laws on injuries. Using hospital-level panel data and triple difference models, we find helmet laws are associated with reductions in bicycle-related head injuries among children. However, laws also are associated with decreases in non-head cycling injuries, as well as increases in head injuries from other wheeled sports. Thus, the observed reduction in bicycle-related head injuries may be due to reductions in bicycle riding induced by the laws.
Lots of people ride bikes. Lots of kids ride bikes. But they can be dangerous. In 2009 alone, bike accidents led to 782 deaths and more than 518,000 visits to emergency rooms in the US. Kids age 19 and under account for 57% of those injuries. A lot of the badness is due to head injuries, especially in kids. In recent decades, we’ve done a lot to promote the use of bike helmets. We’ve done such a good job that not wearing a bike helmet is only second to smoking cigarettes in arousing the public wrath of my children.
Even so, according to this paper, less than half of riders are using helmets regularly nationwide. Some places have implemented laws to make their use mandatory. Do they work to reduce head injuries?
This study examined the association between bike helmet laws and head injuries. But they also looked at the effect of bike helmet laws on bike-related non-head injuries, and injuries from other wheeled activities not affected by helmet laws (ie skateboards). They found that, in kids age 5-19 years, helmet laws were associated with a 13% reduction in the incidence of bike-related head injuries. But they were also associated with a 9% reduction in bike-related non-head injuries.
This means that either wearing a helmet protected the body as well as the head, or that bike helmet laws worked by getting fewer kids to ride bikes. The researchers also saw an 11% increase in injuries from other wheeled activities. This would support the idea that some kids just started riding other devices, and still kept getting injured.
Now it’s still possible to look at these results and argue that bike helmet laws and campaigns lead to safer riding practices, and that has reduced injuries in bikes overall. The data are consistent with that story. But they’re also consistent (perhaps more so, when adding in the increase in other wheeled injuries) with the story that bike helmet laws merely get fewer kids to ride bikes and move to other activities, where they are being injured just as much.
I don’t know what the answer is. I don’t think this will stop me from getting my kids to wear helmets when they ride their bikes, no matter what the laws are in Indiana. For the record, I also make them wear helmets when riding their scooters. It’s the pediatrician in me. But I do hope people look into this further. We don’t want to think we’re solving the problem if we’re really not.
