Helmet Wars
Carlton Reid highlighted this article from the Wall Street Journal . Aside from a major factual error in the final paragraph…
Take President Obama. When he hasn’t been mau-maued by safety fanatics, he makes sensible distinctions. On a Chicago street where he might collide with a car, he wears a helmet. For a leisurely ride on a smooth bike path away from traffic, he doesn’t. There, he simply isn’t going to have the high-speed collisions for which helmets provide valuable protection. The First Daughters’ helmets, like his, are largely symbolic. They are amulets against vulnerability, their gracelessness a sacrifice to the fates.
… it’s quite a balanced piece. I was intrigued by the numbers quoted from research carried out by economists Christopher S. Carpenter of the Merage School of Business at the University of California, Irvine, and Mark F. Stehr of the LeBow College of Business at Drexel University.
The WSJ piece says the research showed that mandatory helmet laws do have a positive impact on fatalities (19% improvement in the age-group affected by the laws), but that there was also a corresponding drop in the total number of people riding bikes.
The number they came up with was that for every life saved, 81,000 few people were riding bikes in the first place.
This got me thinking - what proportion of lives were being saved by the magical properties of helmets, and what proportion were being saved by virtue of there just being fewer people riding bikes in the first place? Here’s where it gets interesting.
According to the League of American Bicyclists , around 57,000,000 people ride a bike at least once a year in the USA. And there are around 700 cyclist fatalities a year. Divide one by the other to find out how many cyclists there are per death, and you get . . . 81,000!
OK - I’m not a real statistician, and we don’t have the background data to do stuff like hypothesis testing to see if these two numbers are linked, or if it’s just a strange coincidence.
But I’ve got to say, it looks to me as if helmets save lives purely by discouraging people from riding a bike in the first place. Period.
Either the sign is pointing in the wrong direction (see arrows on the road) or it’s blocking a cycle lane.
Daily I face the irony of one of those “Think Bike” signs (which should really read “think motorbike”) that has helpfully been attached to the posts holding up a roadsign which helps to block the cycle lane.
A friend of mine was a very good cyclist, training to do the RAAM route. He fell of at about 2mph on the way to the gym and died the next day…..I’ll wear a helmet…..
By the way, he just fell off, no car involved…
Hi Rob - so sorry to hear about that - it’s terrible.
I don’t wear a helmet all the time - only when I’m on a bike with skinny tyres or clipless pedals (so that’s probably >80% of the time). The reason is that with skinny tyres I’m more likely to skid in cornering (especially in the wet - I’ve come off twice like this) and they’re more susceptible to upsets from minor defects in the road surface that chunkier lower pressure tyres would just roll over. The logic for a helmet with clipless pedals is that there’s always a risk of a spud-fall. I’ve had two of those too - near stationary and just unable to get unclipped in time to avoid falling over.
The point isn’t the efficacy or not of helmets though - it’s the impact that helmet laws have on cycling. The health benefits of cycling, compared with a sedentary lifestyle add up to two years longer life and with significantly fewer health problems. So to save one life through mandatory helmets, 162,000 person-years of life are lost. Let’s make the numbers simple, and say that people live around 80 years. What this means is that there’s a 2,000:1 cost to society from mandatory helmets rather than any net benefit.
Well said KarlOnSea, there is a a lot of fearmongering and mis-information out there.
Rob H, wear a helmet if it make to feel better, but the evidence that it will save your life is very thin. I suggest that you have a read of this preliminary report Transport and Health Study Group, in particular Appendix 2A “Cycle Helmet Evidence” which give a good summery of the evidence. Ever wonder why you friend fell off at 2mph? Ever considered that he may have had a stroke? Sadly it is just one of those things which can happen to anyone…
Cycle helmets save very few, if any lives, they just frighten people away from cycling…
Those numbers look fishy. It looks like all you can legitimately conclude is that there was a ratio of 1 cycling fatality per 81,000 riders; or 1:81,000. Nothing in there says whether or not helmets were involved, nor does it suggest anything about decreased riding due to helmet laws.
Correct. But the research as reported by the WSJ says that cycling goes down when helmets are mandatory, and the ratio of fewer cyclists to people not dying is 81,000:1. It may in large part be a coincidence, and again, I’d emphasise that it says nothing at all about the efficacy of a helmet in any specific case. But the fact that there seems to be a very similar ratio makes me wonder if the figures might be related.
I’ve been riding my whole life and a helmet wearing rider for 20 years. I never even questioned the validity of needing a helmet. It made sense to me! Of course I’m also a klutz and have had many interesting crashes over the years.
My husband and I go back and forth because he hates wearing a helmet…. but does want our 3 darling girls to wear theirs. I figure a helmet isn’t going to hurt me, but could help. And my girls? Aside from wrapping them in bubble wrap, we try to take reasonable precautions. And since one of them has inherited my proclivity for falls, we’ll go with helmets.
But it sounds like there is no research to support that? Why are helmets so drilled if they don’t provide a measure of safety?
That’s the problem with statistics - it’s easy to mistake two apparently related figures, and think that one causes the other. The classic example of this is the man walking along the street who insists that snapping his fingers every second keeps elephants away. His evidence is that there are no elephants around, so it must be working!
Do helmets work? Do they provide a degree of protection in the event of certain types of fall? Possibly, but we can’t tell from this data. What we can say is that were helmets are made mandatory, there seems to be a significant drop in the number of people riding bikes.
And as for why helmets are drilled and promoted, you need to look at who’s doing the promotion. Typically, you’ll notice that people who’re in business to make and sell helmets are very sure of their benefits.
The doctors talk about ‘number to treat’ when assessing a drug. It looks like even if helmets are effective, the NTT for bike helmets is very high and given the side effects (reduced ridership leading to more sedentary population) they probably wouldn’t make it through the NICE protocol
Thank you Townmouse - you win this week’s prize for educating the masses - that whole number to treat thing is completely new to me!
The prize is some of my home-baked bagels delivered by post - I’ll email you to get the delivery address!
ooooh. Arrived safely and being saved for tea. TVM!
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