Does Nice Ride increase risk of head injuries?

A Nice Ride bike rental station at West 26th Street and Lyndale Avenue South in Minneapolis, July 2013. Jennifer Simonson/MPR News

Can we please get on the same page on the issue of bike helmets, America?

A few weeks ago in this space, I relayed the assertion that riding a bike without a helmet does not increase the chance of injury.

Writing on Vox, Joseph Stromberg acknowledged that, of course,  you’re better off wearing a helmet if you get hit by a car. But he asserted that if you wear a helmet, you may be more likely to get hit by a car.

He noted that a Canadian study said head injuries have fallen for both riders with helmets and helmets without. And he said drivers might be more careful around the helmetless.

Though US data is scarcer, it’s hard to see the positive overall impact of helmets in the United States either. Between 1995 and 2002, for instance, the number of bike-related concussions suffered by people under 18 declined, but the number of young people who were biking actually dropped much more significantly.

Other data shows that despite increased voluntary helmet use by adults in the US and Great Britain, the overall number of cyclist fatalities hasn’t been affected.

On the whole, when large numbers of people begin wearing helmets, we really don’t see a benefit in the head injury or fatality rates. How is this possible?

That scarce U.S. data? There’s a little more today, NPR reports.

Researchers analyzed five cities — Minneapolis was one of them — with ride-sharing programs (you have to bring your own helmet when you rent a bike from Nice Ride).

The results?

The proportion of head injuries attributed to bike accidents increased in cities after they implemented bike-sharing programs. Overall, there was a 14 percent greater risk of bicycle-related head injuries in people admitted to trauma centers after sharing programs were implemented. There was no increase seen in the control cities.

“The study basically confirmed our worries,” says Janessa Graves, who works on pediatric injury prevention at Washington State University’s nursing school in Spokane. She’s the lead author of the study, published online Thursday by the American Journal of Public Health. “Public bike-share initiatives are great wellness initiatives,” she tells Shots. “But without providing helmets, we were concerned that we would see an increase in head injuries. And we did.”

Now, a study like this one can’t prove cause and effect. Other factors that might have been missed by the researchers could have been at work. The researchers didn’t have information on individual patients and don’t know whether the people who were hurt in bike-share cities were actually using bikes they rented.

Also, a bump seen in the graph showing the proportion of head injuries before the launch of bike-share programs might be a sign of problems with the data.

The study — at least NPR’s version of it — doesn’t seem to address one obvious explanation: If you have a ride sharing program, you have more people riding bikes. If you have more people riding bikes, you’ll have more accidents. If you have more accidents, you have more head injuries.

Is it really the fault of not having a helmet? And is it really the fault of the bike-sharing program that it puts more bikers on the road in cities downtowns — I’m looking at you, Saint Paul — that are decidedly unfriendly for bicyclists?

Besides, a commenter points out what he says is a flaw in the interpretation of the data:

Brain injuries DECREASED in cities after bike-sharing rolled out, compared to the control set of cities where bike sharing was not available. (Note that the ‘before’ data is over 2 years, the ‘after’ data is over 1 year, so expect the ‘after’ data to be 50% of the before, all else being equal.)

What changed was that the proportion of brain injuries relative to all ‘bike-related’ injuries in their dataset increased, which is a different thing, altogether. As others have pointed out, there is no information that distinguishes whether the injured were wearing helmets, or not, or whether the injured were road bikers, stoned ‘side of the road’ weave-in-and-outers, mountain bikers, or had even ever heard about the ride-share program in their cities.

This is not ‘research’, it’s BS data picking, with one plot chosen (Figure 1) to ‘make a point’ that ‘tut-tuts’ everyone about the ‘dangers’ of biking the ‘wrong’ way. Like the authors, I have a PhD, too. I’m ashamed for them. This is junk ‘science’. I wish I had had a chance to review this before the American Journal of Public Health, NPR, and Reddit had got a hold of it!

Unfortunately, we can’t see table 2. It’s behind a paywall.