As a bike commuter, I’m always interested in scientific studies that examine bicycle safety. Including a new study titled, “Pediatric bicycle-related head injuries: a population-based study in a county with out a helmet law” from Injury Epidemiology that looked at the incidence and severity of head injuries for those both wearing and not wearing biking helmets in a U.S. county without a helmet law.
What Ruchi Kaushik, Isabelle M. Krisch, Darrell R. Schroeder, Randall Flick, and Michael E. Nemergut found was that by tracking whether a cyclist with a head injury had a brain injury and/or needed diagnostic imaging against whether or not they wore a helmet, that those without helmets were much more likely to need imaging and/or to have a brain injury.
(For what it’s worth, in my own city, New York, children under 13 and bicycle delivery workers must wear helmets—others are not required by law to wear them.)
Kaushik et al. looked into diagnostic codes from Olmsted County in Minnesota related to bicycle injuries, and specifically if there was documentation about whether or not the injured cyclist had been wearing a helmet (they found that while many accidents had no documentation about that, those involving the head, more frequently, did).
They found that those not wearing helmets were much more likely (32.1% vs. 11.5%) to require diagnostic imaging of the head (X-ray and CT scans), and also more likely (28.1% vs. 13.8%) to have actually sustained a brain injury.
In the end, the authors suggest using all possible means—education, providing free or subsidized helmets, legislation—to get as many cyclists as possible to wear helmets. I always do, and have been grateful for mine when my bike and I have gone down.