published helmet research - not troll

"Steven Bornfeld" wrote

This is something that the anti-helmet partisans continue to repeat,
and I'm not sure what you mean by this. I am inclined to think you're
saying that folks feeling relatively protected will engage in riskier
behavior. I think this is speculative; the same argument the right uses
in this country to attack dispensing of condoms. I've seen plenty of
risky behavior from both helmeted and non-helmeted riders. Of course
this is anecdotal, but I doubt anyone would seriously contend that
people drive more recklessly because they are wearing seat belts.

I've heard the statement, in this newsgroup and others, several times.
Voiced various ways, but the same sentiment

[not verbatim, but close enough]
"I ride harder if I have the helmet on"
"I'm a little more careful if I don't have the helmet on"
"Cycling is just too dangerous without a helmet"
"I would never, ever, ride a bike without a helmet"

And the ever popular "Organ donor" or "Darwinism in action"

Pete

"Shayne Wissler" wrote

Clearly, they're not in the protection business; they're in the business
of selling helmets.

Assuming a free market, it would be in a helmet manufacturers best
interest
to be in the business of both, for the same reasons. In the current
mixed-economy it still makes sense for a helmet manufacturer to be
principally concerned with the performance of the helmet and to let
profits
flow from that--it's the only honest way, and it in fact still could lead
to
becoming a market leader.

Performance (in a crash) doesn't really count, because there are 1) few
enough crashes to matter, and B) no design with current materials that would
actually sell.

Significant, measurable increase in protection would necessitate a
revolution in materials, or a larger helmet. The first is pie in the sky,
and the second won't sell.

Pete

Just zis Guy, you know? wrote:

Here you are wrong: not only do people contend this, it is actually a
mainstream view. Taxi drivers in Germany and Denmark were found to
drive more aggressively in cars fitted with ABS. Drivers who did not
habitually wear seat belts were found to drive faster when persuaded
to wear seat belts. Seat belt legislation has never resulted ina
reduciton in road deaths, but it did lead to the biggest recorded
increase in pedestrian, cyclist and rear-seat passenger deaths in the
UK. The arrival in the second-hand market of the first generation of
cars with drivers' airbags has seen a sharp rise in fatalities of
front seat passengers of young male drivers.

It is very difficult to prove cause and effect in these cases, as most
of these laws were instituted in times of rapidly increasing automobile use.
I can tell you unequivocally in the area in which I have
expertise--facial injuries--that I have never seen a patient with facial
injuries following an auto accident that had been wearing a seat
belt--never.



But the dangers in cycling are low.

This is a tough sell to me. We both know people who have died or been
seriously injured in bicycle accidents.



I would view
effective cycling instruction in the same way. For that matter, one
must demonstrate competence before being licensed to drive a motor
vehicle. In spite of this training many drive with a blatant disregard
to the real dangers.


Because the danger is not to them, or at least they get all the
benefit of the aggressive driving

(!)

and only part of the risk..


Another issue is cultural; in the UK, and in Europe and most of the
rest of the world, the bicycle is seen as a legitimate means of
transportation. In the U.S. it is overwhelmingly still seen as a toy.
As a consequence of this, very few cyclists--even those who bicycle for
legitimate transportation follow even basic transportation regulations.


A great reason to challenge that failing :-)

We do what we can. I'm following the polls.



(As an aside, while on a bicycle tour I once rode through a red
traffic signal in London--a transgression for which I was vigorously
chastised by several pedestrians. I didn't do it again.)


Heh! Red lights are treated as "give way" by all comers, motorised
and cycling, in London :-)


I assume that
the way increased cycling will improve safety is first that there are
less motor vehicles on the road.


- drivers see more cyclists so are expecting them
- drivers are more likely to be cyclists and know how to behave around
them

I can say that this is not my experience. I have been attacked more
frequently when cycling in groups than I have been cycling alone. I
have been attacked more frequently on roads where cyclists are abundant
than on roads where they are not.



Furthermore, I would assume that once
cycling reaches a certain critical mass it will have a political
constituency to effect changes in access, motor vehicle regulations etc.


No, I don't think so. There's no money in it.


If the numbers are there the power and then the money will be.



I have analysed
UK child hospital admissions returns and found that there is no
significant difference in the proportion of head injuries suffered by
road cyclists and pedestrians, despite helemt wearing rates only
around 15%.


Again, I must ask if this pertains to total number of incidents,
proportion of head injuries among total injuries, head injuries per unit
time, etc. This is a complicated issue; I trust that you have looked at
the design of the studies as apparently some of the journals have not.


That's why I stated the figures as I did. Cyclists admissions 49%
head injury, pedestrians 46% head injury, 15% helmet wearing rate.
So: cyclists and pedestrians suffer roughly the same proportion of
head injuries. The ratio is pretty much unchanged with helmet use.
By comparing the ratio you normlaise out exposure. You can do similar
calculations with severity ratios and show that the proportion of
cyclist inuries which are severe are unaffected by helmet use.

I'm still not understanding this. This is percentage of total
admissions? Percentage of accident admissions with head injury?


By contrast, Liddites claim "head injuries fell in Australia following
the law" which is literally true, but they fell by less than the fall
in the number of cyclists.

Look at graph 2 he http://agbu.une.edu.au/~drobinso/bhacc.htm




You're supposed to try to disprove, not prove, your
initial premise. In this case the researchers [...] decided on the
outcome before they started.


Well, sure. That's the way it is supposed to be. But drug trials are
not conducted by folks looking for the drugs not to work. Of course,
one cannot do a double-blind study on this. But this is a very serious
charge against the NEJM, and I would have expected to hear about it.


It's not a particularly serious charge against them, actually; it's a
study with an error in it. It happens all the time. It is an
indictmentof their peer review process, though. But not as bad as the
Cook & Sheikh paper in Injury Prevention.

I have to disagree. If I understand the error as you state it, it is
both blatant and elementary. Any responsible editor should have seen
it. Having not seen it beforehand, in a journal of the pedigree of
NEJM, the editor should have been history. This does NOT happen all the
time, thank God.






Well, as you say, there's cycling, and then there's cycling. I made a
decision after a serious crash in my first year racing that I was
finished. It's a bargain you make with yourself--I won't race again and
THEN I'll be safe. I was not spared a head injury by my helmet, but I
probably saved myself having my eyes cut up by the broken glass I fell into.


Sure. I don't do technical downhill - too risky. I fact the kind of
riding I do it's very unlikely a helmet would ever be of benefit, not
least because I ride with my arse a foot off the ground :-)


Now, this is likewise the kind of statistic that bothers me. I am
assuming that you are speaking of cardiovascular risk. OK. But the
choice should not be cycling vs. couch potato. I have never seen a
study actually pretend to predict life extension based on a particular
volume of cardiovascular exercise anyway. However, for those who cycle
for fitness instead of purely for transportation (as I do) one cannot
assume that someone who stops cycling will do no other aerobic exercise.
There are other confounding factors, such as that those who bicycle or
do other forms of aerobic exercise are less likely to smoke. I have
seen studies that attempt to correct for this, but they are mostly fantasy.


Sure - but the message is sound. Cyclists live longer than average;
this would not be possible if cycling were extraordinarily dangerous.


This may or may not be true. I have no reason to believe that the
cycling population is heterogeneous. I do have reason to believe that
avid cyclists (the ones most likely to enjoy a health benefit) are
considerably more affluent and get better medical care than the general
population.



These are the proportions of all admissions which are due to head
injury. So, if you have a bike crash, you are not markedly more
likely to suffer head injury than if you are hit as a pedestrian.


This assumes that the total number of person-hours spent cycling is
roughly equivalent to the total number of person-hours spent as a
pedestrian.


No it doesn't, because it compares like with like. You have already
been injured: is your injury more likely to be a head injury if you
are a cyclist? Answer, not really. Are you more likely to be injured
per se as a cyclist? Probably not, inless there is a motor vehicle
involved.


The risk levels comparison: 10% of cycling is on road, 90% off road.

This is a simply amazing statistic. In the U.S. even most mountain
bikes are never ridden off road.


Includes bike paths and trails. You might be surprised :-)


Not likely in the U.S. Bike trails are relatively rare here.
Furthermore, even roads with dedicated bicycle paths frequently carry
motor vehicles as well.



So what would you change? As you've pointed out, cars are heavily
regulated because of the greater danger. The industry is more powerful
economically and politically. So what would be the focus of improving
bicycle safety vis a vis automobiles?


First, enforce traffic regulations (for all road users) inna zero
tolerance stylee. Second,make sure that quality bike training is
available for all. And third, make sure that anybody who drives badly
gets a chance to find out how the other half live as they do without
their license for a while.

That's a noble sentiment. I fully expect to die before seeing this though.



Thanks for your interesting and thorough discussion. This is obviously
an important issue for you. The issue of helmet mandates is frankly
unimportant to me. What is important is the truth regarding helmets and
bicycle safety, for myself and my family. As someone who has been
permanently injured in crashes I'm sure it is something on which we both
can agree


It is a matter of life and death, literally. I spend between one and
two hours every weekday riding my bike on the roads, and I have kids.
I cannot afford not to take an interest :-)

Guy

Hold on--I thought this was a relatively safe activity! ;-)

Steve

Snoopy *is n wrote:


What I have just stated in not definitive proof of anything. But I
do want to suggest that correlating cycle use with the introduction of
cycle helmet laws is not just the statistical exercise it might appear
to be.

Although they haven't been mentioned in the current thread, the best
measurements correlating reduction in cycle use and helmet laws come
from Australia.

What was seen there was a significant step drop exactly concurrent with
the introduction of the law. The counts in Victoria (IIRC) used trained
observers before and after the law, monitoring use in the same places
under the same weather conditions. Other data came from automatic
devices placed on bridges commonly crossed by cyclists.

And while correlation does not prove causation, they did do telephone
surveys asking people about their cycling. Respondents said they were
cycling less because of the law.

As I've said before, it's unreasonable to expect anything but a drop in
cycling upon imposition of a MHL. The only question is how large the
drop will be. I say this because it's certain _someone_ will say they
won't cycle if they have to wear a helmet. (Also, you'll probably have
some parents who will say "Damn, if it's _that_ dangerous, I'm not
letting you cycle at all!")

But it's hard to imagine anyone saying "Gee, now that a helmet is a
requirement, that makes me want to take up cycling."

--
--------------------+
Frank Krygowski [To reply, remove rodent and vegetable dot com,
replace with cc.ysu dot edu]

Pete wrote:
"Steven Bornfeld" wrote

This is something that the anti-helmet partisans continue to repeat,
and I'm not sure what you mean by this. I am inclined to think you're
saying that folks feeling relatively protected will engage in riskier
behavior. I think this is speculative; the same argument the right uses
in this country to attack dispensing of condoms. I've seen plenty of
risky behavior from both helmeted and non-helmeted riders. Of course
this is anecdotal, but I doubt anyone would seriously contend that
people drive more recklessly because they are wearing seat belts.


I've heard the statement, in this newsgroup and others, several times.
Voiced various ways, but the same sentiment

[not verbatim, but close enough]
"I ride harder if I have the helmet on"
"I'm a little more careful if I don't have the helmet on"
"Cycling is just too dangerous without a helmet"
"I would never, ever, ride a bike without a helmet"

And the ever popular "Organ donor" or "Darwinism in action"

Pete

I can't say this doesn't happen BUT in my experience, risk-averse folks
are careful. People who don't care won't care to protect themselves.
That means reckless folks won't wear helmets, and they'll ride recklessly.
Have I seen reckless riders with helmets? Sure. But I tend to doubt
they are reckless because of the helmet. They are reckless
because...they are reckless.

Steve

Steven Bornfeld wrote:


I only suggested to those who opposed mandatory helmets by saying
that other measures were more important to safety that their objections
had more to do with freedom to choose than it did to the efficacy of
helmets.

For me, it's not simply freedom to choose.

To illustrate - and hopefully not get the discussion off track: There
are other issues regarding which I disagree with the lack of freedom to
choose, but I don't get very concerned.

And example would be air bags in cars. From the reading I've done, they
are not the panacea they are proclaimed to be - that is, IIRC, they
offer only about 8% improvement in survival over a properly fastened
seat & shoulder belt, yet they cost far, far more and they have the
capability of killing people. (Certainly, "First do no harm" should
apply to safety devices as well as physicians!)

However, I'm not going to devote time to that particular
freedom-to-choose issue. I think the societal negatives are relatively
minor.

The overpromotion of bike helmets is, to me, another matter. It does
harm society by discouraging cycling. It tends to place the blame for
certain injuries on victims. It distracts from more effective (and
bicyclist-friendly) tactics that would do greater good for cycling
safety and for cycling in general. It falsely portrays ordinary cycling
as extremely dangerous. And, as icing on the cake, it uses false logic
and incompetent science - something that would irritate me about most
issues.

So it's not just a freedom issue. Sure, that's there, as well, but
there are lots of freedom issues that lead me to say nothing more than
"Oh well."

--
--------------------+
Frank Krygowski [To reply, remove rodent and vegetable dot com,
replace with cc.ysu dot edu]

Frank Krygowski wrote:
Steven Bornfeld wrote:


I only suggested to those who opposed mandatory helmets by saying
that other measures were more important to safety that their
objections had more to do with freedom to choose than it did to the
efficacy of helmets.


For me, it's not simply freedom to choose.

To illustrate - and hopefully not get the discussion off track: There
are other issues regarding which I disagree with the lack of freedom to
choose, but I don't get very concerned.

And example would be air bags in cars. From the reading I've done, they
are not the panacea they are proclaimed to be - that is, IIRC, they
offer only about 8% improvement in survival over a properly fastened
seat & shoulder belt, yet they cost far, far more and they have the
capability of killing people. (Certainly, "First do no harm" should
apply to safety devices as well as physicians!)

However, I'm not going to devote time to that particular
freedom-to-choose issue. I think the societal negatives are relatively
minor.

The overpromotion of bike helmets is, to me, another matter. It does
harm society by discouraging cycling. It tends to place the blame for
certain injuries on victims. It distracts from more effective (and
bicyclist-friendly) tactics that would do greater good for cycling
safety and for cycling in general. It falsely portrays ordinary cycling
as extremely dangerous. And, as icing on the cake, it uses false logic
and incompetent science - something that would irritate me about most
issues.

So it's not just a freedom issue. Sure, that's there, as well, but
there are lots of freedom issues that lead me to say nothing more than
"Oh well."

As I said, if there is no significant safety issue, there is no need to
speak of regulation at all.

Steve

Frank Krygowski wrote:
Steven Bornfeld wrote:



Just zis Guy, you know? wrote:


But the dangers in cycling are low.



This is a tough sell to me. We both know people who have died or
been seriously injured in bicycle accidents.


I've literally lost count of the people I know who died or were
seriously injured while riding in motor vehicles. I imagine this is
true of most people. Yet most people don't ever say "Damn - riding in a
motor vehicle is really dangerous." They obviously think the danger is
low.

Clearly, knowing one or more injured people proves little about an
activity's relative danger. It's much more instructive to dig for data
on, say, injuries or fatalities per hour exposure.

True, the data's hard to find. But the available data for cycling seems
to belie the "Cycling is dangerous" nonsense.

I don't doubt this. Personally, I hear discussion about the sorry
state of autmotive safety all the time. I am lucky enough to know no
one personally who has been seriously injured in an auto-only accident.
Obviously, this doesn't mean it doesn't happen. By the same token, I
know several people who have suffered life-threatening injuries cycling,
about half of them with no motor vehicles involved.
I am not about to soft-pedal (nyuck, nyuck) the dangers of either.

Steve

Steven Bornfeld wrote:



Just zis Guy, you know? wrote:


But the dangers in cycling are low.


This is a tough sell to me. We both know people who have died or
been seriously injured in bicycle accidents.

I've literally lost count of the people I know who died or were
seriously injured while riding in motor vehicles. I imagine this is
true of most people. Yet most people don't ever say "Damn - riding in a
motor vehicle is really dangerous." They obviously think the danger is low.

Clearly, knowing one or more injured people proves little about an
activity's relative danger. It's much more instructive to dig for data
on, say, injuries or fatalities per hour exposure.

True, the data's hard to find. But the available data for cycling seems
to belie the "Cycling is dangerous" nonsense.


--
--------------------+
Frank Krygowski [To reply, remove rodent and vegetable dot com,
replace with cc.ysu dot edu]

Frank Krygowski wrote:
Steven Bornfeld wrote:



Pete wrote:

"Steven Bornfeld" wrote

This is something that the anti-helmet partisans continue to repeat,
and I'm not sure what you mean by this. I am inclined to think you're
saying that folks feeling relatively protected will engage in riskier
behavior. I think this is speculative; the same argument the right
uses
in this country to attack dispensing of condoms. I've seen plenty of
risky behavior from both helmeted and non-helmeted riders. Of course
this is anecdotal, but I doubt anyone would seriously contend that
people drive more recklessly because they are wearing seat belts.




I've heard the statement, in this newsgroup and others, several times.
Voiced various ways, but the same sentiment

[not verbatim, but close enough]
"I ride harder if I have the helmet on"
"I'm a little more careful if I don't have the helmet on"
"Cycling is just too dangerous without a helmet"
"I would never, ever, ride a bike without a helmet"

And the ever popular "Organ donor" or "Darwinism in action"

Pete



I can't say this doesn't happen BUT in my experience, risk-averse
folks are careful. People who don't care won't care to protect
themselves. That means reckless folks won't wear helmets, and they'll
ride recklessly.
Have I seen reckless riders with helmets? Sure. But I tend to
doubt they are reckless because of the helmet. They are reckless
because...they are reckless.


The issue is more subtle than just "reckless with [or without] helmets."
The question is, when a helmet is put on a person's head, how does
their recklessness _change_?

Even a cautious person can exhibit risk compensation, and they regularly
do it. Again, even someone saying "I would never ride a bike without a
helmet" is admitting to risk compensation. They are admitting to
increasing what they perceive as risky behavior, because they perceive a
degree of protection.

Interestingly, if they underestimate the degree of protection, but
accurately estimate the increased riskiness of their behavior, they
still come out ahead.



But in a climate where the most-quoted claim of helmet benefit is so
outrageously high (85%) there must be lots of people who overestimate
the real protection.

"85%? Hell, that's close to 100%! I'll _never_ get a head injury if I
wear this thing. Banzai!!!"

I'm sure that happens all the time! ;-)

Steve