Friday, May 8, 2009

Helmets

Because this is a generally humorous blog…

No, wait. Maybe that’s going too far.

Because this is a blog that generally tries to be humorous…

That’s better.

I thought we’d talk about death and injuries today, largely because I came across a website that annoyed me. Yes, I know that it’s dangerous to write a blog post while annoyed, but I’ll take the risk. The website in question was written by someone who can’t figure out why cyclists bother to wear helmets. He wanted to find out if helmets are really of any use.

So we thought we'd cast aside all the "it just makes sense" and "if just one life is saved" rubbish and find some real, hard numbers to evaluate the effectiveness of crash helmets.

Now, as a scientist (and a card carrying geek), I am all in favor of using real, hard numbers to evaluate things. On the other hand, I don’t think I’d automatically toss out “it just makes sense” and “if just one life is saved” as being rubbish. Anecdotal evidence isn't necessarily inaccurate.

So, on this website they compared fatality rates per 10,000 vehicles, per 1 million population and per 1 million miles traveled and compared cars, bikes, motorcycles and pedestrians, and they found that the death rates for pedestrians and cyclists were about the same for every million miles traveled (though cyclists were quite a bit more likely to be injured than pedestrians were). Oh, and they also found this out:

It turns out that alcohol is a major player in all fatalities, not just car crashes. Drunk drivers cause 40% of car fatalities; drunk riders cause 29% of motorcycle fatalities; drunk bicyclists cause 24% of bicycle fatalities; and drunk pedestrians (we are not making this up) cause 33% of pedestrian fatalities. Apparently, staying sober while trying to move, or not trying to move while drunk, are both excellent ways of improving one's odds of survival.

I just reprinted that part because the concept of drunk cyclists (and drunk pedestrians) startled me, although I suppose it shouldn’t have.

Scientific studies can generally be divided into two groups:

1. Wow. I didn't know that - Viruses aren't actually living organisms.

2. No duh - Students who read do better in school.

I mention this because I would have thought that the concept that driving or riding or walking or operating heavy machinery or attempting to ride an elephant while drunk is probably bad is a "no duh" kind of result.

Now, let’s assume for the sake of argument that all of the data presented on this website is accurate. It is jam packed with table like this one:


Death Rate

Injury Rate

From cancer

2010

N/A

From pneumonia/flu

237

N/A

From poisoning

73.5

1842

From falling

50.9

27100

From suffocation

44.0

137

While walking

16.9

280

From Drowning

14.8

28.5

While driving

12.9

987

While motorcycling

9.8

717

On horseback

3.8

127

While bicycling

2.5

453

Struck by lightning

2.0

8.0

While skiing

0.2

43




















which is then summed up like this:

Nearly twice as likely to be killed by a horse, six times more likely to drown, 100 times more likely to die of pneumonia or the flu, than to be killed while riding a bicycle. More than twice as likely to be seriously injured in a car, and four times as likely to be poisoned, than seriously injured on a bicycle. And keep in mind, according to the CDC, only a third of those bicycle injuries are head injuries.

Well, how many of those riders who didn’t get head injuries were wearing helmets? How many of the riders who got head injuries were wearing helmets. I didn’t actually find that information on the website, so either I missed it or the author didn’t know, but it seem a relevant point to me.

And the conclusion to be drawn from the mountain of data?

Helmets save lives? Well, sure, occasionally they do.

Oh, well, if it’s only occasionally…

In the real world, biking is no more dangerous than taking the dog for a walk, and often even safer.

I’ve been walking a dog for considerably longer than I’ve been riding a bike, but I’ve never had any dog walking related injuries, and I’ve never met anyone who has had any dog walking related injuries. I have picked up a few cycling related injuries and I know quite a lot of people who have picked up cycling related injuries. I also know a couple of people who, if they hadn’t been wearing helmets, would probably be in a lot worse shape than they are today (one of those people being me). I’ll grant you that this is only anecdotal evidence, but it persuades me.

And the final word from the author of the website?

We feel no more need for a helmet than we feel the need to strap a lightning rod to our shorts. But then again, we don't bother playing the lottery either.

I’m not quite sure how to take this. Does this mean that the author feels like he needs to wear a helmet or not? I don’t know. I do know that I won’t ride without one, and I hope you won't either.

See you on the road.

Hopefully with a helmet on your head.

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