Monday, April 27, 2009
Do bicycle helmets harm the public health?
If it were not for all the math, I'd love to be an actuary. They get to study the net effects of different activities in isolation and often come up with very counterintuitive results. See, e.g., this abstract of a paper that purports to show that bicycle helmet laws may have a net negative public health effect because, to be reductionist about it, requiring helmets makes biking so uncool or uncomfortable that people do much less of it than when helmets are not required. From the paper itself (click through the link in the abstract):
Generally there has been solid support for bicycle helmet laws in Canada, Australia and New Zealand, less so in the US and the UK, and little support in northern European countries such as the Netherlands and Denmark, where cycling is far more popular. Reasons for lack of support include the following. First, helmets reduce cycling and hence the impact of "safety in numbers." Second, helmets may promote the view and possible misconception that cycling is a relatively dangerous activity. Third, helmets may draw attention and harm prevention activities away from the real causes of cycling accidents. Finally, helmets may promote the view that cycling is a non normal activity only to be undertaken with specialized equipment.
A reduction in cycling has negative environmental and health consequences. DeMarco (2002) opines: "Ultimately, helmet laws save a few brains but destroy many hearts." Ignoring any environmental costs associated with reduced cycling, the efficacy of helmet laws hinges on whether the positive direct benefits (fewer head injuries) outweigh the indirect negative effects (less exercise).
There are, of course, environmental consequences as well. Bicycles do not pollute, do not require imported oil or the enrichment of Arab dictators and kings, do not make noise, and do not take up nearly as much space on the road. If those considerations are factored in, do helmet laws lose all their net utility? It is possible. The Dutch, who ride bicycles like a people possessed, do not require the wearing of helmets in part because they worry that fear of "hat head" will cause people to stop commuting by bike and take up driving instead. I admit, hat-head considerations keep me from riding my bike to work as well, unless I leave time to shower when I get there.
Interestingly, there is a whole web site with lots of linkage given over to this question. If you want to build the case against cycling with a helmet, there's your resource.
Important disclaimer: My company makes products for neurotrauma. As such, I see a lot of neurotrauma case studies, and have developed a preferential interest in avoiding trauma to my own head or the head of any loved one. Therefore, I wear a helmet when I ride a bike or ski, and require that my children do the same, actuarial hoo-ha notwithstanding.
12 Comments:
By 
, at
Mon Apr 27, 09:34:00 PM:
I've been a club cyclist for 10 years now. Helmets are required on club rides. Period. Professional cycling also requires helmets, after too many riders died or suffered serious injury. Yes, "helmet hair" is a downer. But brain injury is worse. In my 10 years with the club, we've had a handful of fatalities, and a number of serious head injuries. And we are just normal folks riding, not racing, bikes for health and recreation. I don't much care about the actuarial arguments. I won't ride without a helmet. I've crashed enough times to know the value of the "brain bucket."
By 
Georg Felis, at
Tue Apr 28, 12:20:00 AM:
Figures lie, and liars figure.
With that said, the wife and I were hit from behind while making a left hand turn some years ago. Without helmets, neither of us would be here. Road rash heals, cracked skulls not so much. Helmets save lives, wear them.
By Noumenon, at
Tue Apr 28, 01:33:00 AM:
Funny, I had no idea actuaries did stuff like that. That paper looks like economics to me.
So maybe an incentive program instead of a law? The government gives you a coupon for a new helmet when you buy a bike?
By TigerHawk, at
Tue Apr 28, 07:31:00 AM:
Assuming that the linked paper's analysis is true, it points out a tension between individual health and the public health. Yes, people who ride bikes are better off with helmets, so they should by all means wear them (as I do). But in doing so, they discourage many more people from riding. This has two perverse consequences. First, those discouraged people are less healthy, on average, than if they rode even without a helmet. Second, even the helmet-riding bikers are less safe because the roads become more dominated by cars than bikes. If, after all, there were swarms of bikes on our roads automobile drivers would need to change their behavior.
By Cas, at
Tue Apr 28, 08:03:00 AM:
perhaps as Noumenon suggested, instead of FORCING everyone to wear a helmet, they could persuade you to wear one, and those who care about the safety of their skulls will wear one.
Since I'm already so far out of fashion, I've never let something like "helmet hair" bother me. But, at least they could make most of the helmets look COOLER, like the racing helmets shaped like teardrop (like I'll ever need to minimize aerodynamic drag!) or with better colors. Maybe I just bought the cheapest one...
By Cardinalpark, at
Tue Apr 28, 08:14:00 AM:
All I can say is that the analysis turns logic on its head; it's idiotic.
Riding is among my favorite workouts, and I workout alot. Wear a helmet. Also - see Richardson story from ski season - wear a helmet when you ski too.
By , at
Tue Apr 28, 09:27:00 AM:
Interesting, but not surprising to learn that requiring helmets reduces bike riding. Maybe we should require motorists and their passengers to wear helmets at all times as well? It makes at least as good a safety case as helmets do for bikes. Perhaps it would lead to less driving and fuel consumed?
By Mystery Meat, at
Tue Apr 28, 10:29:00 AM:
Years back, I read a report in a California newspaper claiming that motorcycle helmet laws had increased the death rate. The logic is that dead motorcyclists were the source of organs for transplant. A motorcyclist could "save" up to four people with his heart, kidneys and liver. So helmet laws in this instance resulted in a net increase in overall deaths.
By Mystery Meat, at
Tue Apr 28, 10:32:00 AM:
Correction: Motorcyclists were A common source of donated organs, not THE source.
By kentuckyliz, at
Tue Apr 28, 08:45:00 PM:
Not following you, Meat. Wouldn't that be a net decrease of deaths, because of the multiple lives saved by each motorcyclist's organs?
By Retriever, at
Tue Apr 28, 09:02:00 PM:
The one time I did not wear a bicycle helmet (vanity, going to a party, didn't want to flatten my hair) in grad school (too poor for a car) I was in a bike accident and needed the plastic surgeon to sew up my face. I have worn a helmet ever since whenever I ride a bike.
Also, I was a chaplain in a neurointensive care unit and the ER at one point and am therefore rabid on the subject of my family wearing helmets...
It's all moot where I live now, tho, as it is not safe to ride a bike at all given the narrow roads, lack of bike lanes and roads overcrowded with Suburbans and Escalades and minivans.
By Mystery Meat, at
Tue Apr 28, 11:55:00 PM:
"Not following you, Meat. Wouldn't that be a net decrease of deaths, because of the multiple lives saved by each motorcyclist's organs?"
If the motorcyclist dies, four other people will get his organs and live. If the motorcyclist lives, the four people who didn't get his organs die. Thus the net increase in the number of deaths.
