Stupid helmet question ...

In message
"pg" wrote:

[snip]

Interesting rebuttal of risk homeostasis he
http://ip.bmj.com/cgi/content/full/4/2/92


However this argument above is challenged and discussed further at

http://www.bmj.com.cgi/content/full/324/7346/1149

Mike
--
o/ \\ // |\ ,_ o Mike Clark
\__,\\ // __o | \ / /\, "A mountain climbing, cycling, skiing,
" || _`\,_ |__\ \ | immunology lecturer, antibody engineer and
` || (_)/ (_) | \corn computer user"

Mike Clark wrote:
In message
"pg" wrote:

[snip]

Interesting rebuttal of risk homeostasis he
http://ip.bmj.com/cgi/content/full/4/2/92


However this argument above is challenged and discussed further at

http://www.bmj.com.cgi/content/full/324/7346/1149


rant
No it's not - that gives page not found. Which makes sense, unlike "Risk
homeostasis *Theory*". The only time this *theory* is propounded is when
someone wants to claim that some peice of safety equipment doesn't make you
safer if you use it. And it is obvious rubbish, people use safety equipment
to be safer, not so they can be more dangerous.. [Sorry champ I know you
deliberately do the opposite ]
/rant
--
Chris *:-)

In message
"MoonMan" wrote:

Mike Clark wrote:
In message
"pg" wrote:

[snip]

Interesting rebuttal of risk homeostasis he
http://ip.bmj.com/cgi/content/full/4/2/92


However this argument above is challenged and discussed further at

http://www.bmj.com.cgi/content/full/324/7346/1149


rant
No it's not - that gives page not found.

Sorry http://www.bmj.com/cgi/content/full/324/7346/1149

Which makes sense, unlike "Risk homeostasis *Theory*". The only time
this *theory* is propounded is when someone wants to claim that some
peice of safety equipment doesn't make you safer if you use it. And
it is obvious rubbish, people use safety equipment to be safer, not
so they can be more dangerous.. [Sorry champ I know you deliberately
do the opposite ] /rant -- Chris *:-)


So you don't believe that people change their behaviour based on their
perception of risk?

Those that attack risk compensation, such as the article by Robertson
and Pless seem to be attacking a single idealised concept of "risk
compensation", based on an idea that risks will always tend to the same
level over a period of time. However few, and this includes Wilde, hold
to this rigid concept of unvarying risk tolerance and indeed it is
accepted that it is possible to change peoples tolerance levels to risk.

Very few people are in a position to make calculated decisions about
risk based on real actuarial data. So most people base their decisions
on their own perceptions as informed by general observation and perhaps
on publicity in the media. So for example people seem to be far more
risk adverse with regard to plane and train crashes, than they are with
car crashes, despite the facts that the risks of injury in planes and
trains is much lower than in travelling by car.

Mike
--
o/ \\ // |\ ,_ o Mike Clark
\__,\\ // __o | \ / /\, "A mountain climbing, cycling, skiing,
" || _`\,_ |__\ \ | immunology lecturer, antibody engineer and
` || (_)/ (_) | \corn computer user"

Mike Clark wrote:
In message
"MoonMan" wrote:

Mike Clark wrote:
In message
"pg" wrote:

[snip]

Interesting rebuttal of risk homeostasis he
http://ip.bmj.com/cgi/content/full/4/2/92


However this argument above is challenged and discussed further at

http://www.bmj.com.cgi/content/full/324/7346/1149


rant
No it's not - that gives page not found.

Sorry http://www.bmj.com/cgi/content/full/324/7346/1149

Which makes sense, unlike "Risk homeostasis *Theory*". The only time
this *theory* is propounded is when someone wants to claim that some
peice of safety equipment doesn't make you safer if you use it. And
it is obvious rubbish, people use safety equipment to be safer, not
so they can be more dangerous.. [Sorry champ I know you deliberately
do the opposite ] /rant -- Chris *:-)


So you don't believe that people change their behaviour based on
their perception of risk?

Those that attack risk compensation, such as the article by Robertson
and Pless seem to be attacking a single idealised concept of "risk
compensation", based on an idea that risks will always tend to the
same level over a period of time. However few, and this includes
Wilde, hold to this rigid concept of unvarying risk tolerance and
indeed it is accepted that it is possible to change peoples tolerance
levels to risk.

Very few people are in a position to make calculated decisions about
risk based on real actuarial data. So most people base their decisions
on their own perceptions as informed by general observation and
perhaps on publicity in the media. So for example people seem to be
far more risk adverse with regard to plane and train crashes, than
they are with car crashes, despite the facts that the risks of injury
in planes and trains is much lower than in travelling by car.

You've made my point for me, How can people Risk Compensate? they have no
real knowledge of what risk is, for example many people (current company
excluded of course) think that if you are exposed to a "Cancer causing
chemical" you *will* get cancer,rather than increasing a hypothetical small
chance that you might get cancer, as you stated people think planes are
dangerous when they are in fact one of our safest forms of transport. So how
can you judge the exact amount a device makes you safer, then act exactly
that much (or actually acording to the theory slightly more) stupidly? it
just doesn't make sense.

--
Chris *:-)

In message
"MoonMan" wrote:

[snip]
You've made my point for me, How can people Risk Compensate? they have
no real knowledge of what risk is, for example many people (current
company excluded of course) think that if you are exposed to a
"Cancer causing chemical" you *will* get cancer,rather than
increasing a hypothetical small chance that you might get cancer,

So why do so many young people take up smoking?

as you stated people think planes are dangerous when they are in fact
one of our safest forms of transport. So how can you judge the exact
amount a device makes you safer, then act exactly that much (or
actually acording to the theory slightly more) stupidly? it just
doesn't make sense.


OK so I see that you fall into the camp of believing that risk
compensation is about continually adjusting to an exact numerical risk.
I don't hold to that view.

My view of risk compensation is that people build up different
perceptions of what is dangerous and what is acceptable. Those views are
based on their own observations as well as on how things are presented
to them in the media. If you then feed them information that appears to
make something more or less risky than it really is they will adjust
their behaviour accordingly.

Since people are not able to easily determine exactly the level of risk
they are exposed to, the danger comes if publicity over, or under,
emphasises the degree of protection that a safety device offers, since
the individuals will adjust to their perception of danger, not
immediately to the real level of danger.

Mike
--
o/ \\ // |\ ,_ o Mike Clark
\__,\\ // __o | \ / /\, "A mountain climbing, cycling, skiing,
" || _`\,_ |__\ \ | immunology lecturer, antibody engineer and
` || (_)/ (_) | \corn computer user"

"Mike Clark" wrote in message
.uk...
| In message
| "pg" wrote:
|
|
| "Mike Clark" wrote in message
| .uk...
| | In message
| | "pg" wrote:
| |
| | [snip]
| | In the (only) group I have been discussing (ski racers /
mountain
| | dwellers), I reckon the effect - if any - would be negligible.
| |
| |
| | The simple way to demonstrate that you are right would be to show
that
| | mountain dwellers and ski racers were at much less risk than you'd
| | expect from the general population. I'd hypothesise that if you
did
| | find such data that you'd find that ski racers and mountain
dwellers
| | are likely to be at a higher risk than the general population
| | because familiarity with risk tends if anything to make people
less
| | cautious.
|
| So you would be safer being driven along a wet country road with 'Mr
| Ordinary Sunday driver' at the wheel, than as Michael Schumacher's
| passenger? More secure than on a winding, icy road sitting next to
| Sebastien Loeb?
|
| You're misunderstanding risk compensation again. If extra skills lead
| the individual to expose themselves to a higher risk more of the time
| the net effect may be a higher chance of an accident.
|
| Take racing and training out of the equation, and I would wager that
| this target group are at a greatly reduced risk level.
|
| Peter Bourne and Gianclaudio Regazzoni are two recent examples of
racing
| drivers who have been killed in motor accidents on the road.
|
| Because one can go very quickly indeed doesn't mean than one is
| compelled to.
|
| Agreed what we are considering is whether there is a higher
probability
| of taking risks.
|
| Beyond a certain age this is certainly not the case (I would guess
| 30/35+), and amongst the younger generations, they quickly gain a
| maturity and understanding of the genuine risks involved, of which
| most holiday skiers are unaware.
|
| Look the available data is very clear for general recreational skier
| injury rates, it is measured in terms of just a few injuries per 1000
| skier days of participation. If you compare that to race skiers it is
a
| few injuries per 1000 runs and that frequency seems to be true for
| National Championships as well as World Cup. So competitive skiers
seems
| to suffer more frequent injuries than recreational skiers. That
doesn't
| surprise me because it is clear to me that competitive skiers are
| prepared to push themselves to the limit even if it does risk injury.
| Many competitive skiers retire with lifelong effects from the injuries
| and any surgical treatments needed.
|
|
| Your hypothesis above completely ignores training, skill, fitness,
| familiarity with terrain, snow conditions and weather, knowledge of
| how to fall, instinctive awareness of what you can and cannot take
on.
| It also ignores certain negative factors adversely affecting the
short
| holiday skier on a quick dash to the snow.
|
|
| No my hypothesis is that knowledge of all the above leads individuals
to
| expose themselves to greater risk and hence the probability of injury
to
| the individual is often increased rather than decreased.
|
| As to ski racers being immune from "risk compensation" ask
yourself
| this simple question. Do you think that ski racers are more or
less
| likely to be injured whilst recreational skiing or whilst racing
or
| training?
|
| Vastly less, obviously. But I've only (throughout) been referring to
| relative immunity *with respect to the wearing, or otherwise, of a
| helmet, by genuinely expert skiers.* You're shifting the goal posts.
|
| No I'm not shifting the goalposts, all I'm saying is that you've
picked
| a sub group for which we can't find data one way or the other. However
| your hypothesis seems to be based on an idea that experts are immune
to
| risk compensation, whereas other studies show this not to be the case.
|
| With respect to ski racing/training we're talking about calculated
| risks consciously taken, not the hypothetical ones skiers may or may
| not take on unconsciously when they don a helmet.
|
| I flippantly questioned - with respect to a ski racer who has worn a
| helmet since he first slid down a slope - whether wearing a
different
| colour pair of socks would encourage him to ski with a different
| (safer/less safe) attitude. If the answer is no, then you prove my
| point. To a ski racer a helmet is an item of clothing, part of the
| uniform, no more, no less.
|
| So why present evidence that helmets are an item of safety equipment
if
| to you they are merely an item of clothing?
|
|
|
| With respect to risk compensation and lids across skiing as a whole,
| you might be interested in this brief summary of a study. It has an
| interesting conclusion: "Helmet use by skiers and snowboarders
| continued to trend upwards and does not appear to motivate more
risk
| taking. Helmet wearers engaged in less risk behavior than
| non-wearers, suggesting that decisions to adopt helmets are
motivated
| by safety concerns."
|
| Interesting study.
|
|
| http://www.cdc.gov/NCIPC/lifeguard/2...stractBook.pdf
(a
| very large pdf).
|
| On page 148 there a piece entitled: "Testing the Risk Compensation
| Hypothesis for Safety Helmets in Alpine Skiing and Snowboarding".
|
| Michael D Scott, PhD1, DB Buller, PhD2, PA Andersen, PhD3, BJ
Walkosz,
| PhD4, JH Voeks, PhD5, MB Dignan, PhD6, GR Cutter, PhD5
| 1California State University, Chico, CA; 2The Cooper Institute,
Denver,
| CO; 3San Diego State University, San Diego, CA; 4University of
Colorado,
| Denver, CO; 5University of Alabama, Birmingham, AL; 6University of
| Kentucky, Lexington, KY
|
| "Background/Objectives: Previous surveys showed increasing adoption
of
| helmets by skiers and snowboarders. Efficacy of helmets for these
sports
| has been questioned on the basis of risk compensation. This survey
| tracked helmet use by skiers and snowboarders and tested for risk
| compensation.
|
| Methods: Helmet use was recorded in face-to-face interviews with
1,779
| adult skiers and snowboarders at 31 ski areas in Western North
America
| in January-March 2003. Respondents were asked two questions
assessing
| risk compensation: do they (a) ski/snowboard faster, slower or about
the
| same speed and (b) challenge themselves more, less or about the
same.
| Helmet wearers compared current behavior to when they did not wear a
| helmet; non-wearers, to previous seasons.
|
| Results: In 2003, 23.0% were observed to be wearing a helmet (12.1%
in
| 2001; 19.6% in 2002). Significant univariate predictors of use
(p.05)
| were included in a multivariate logistic regression to identify the
| strongest predictors of higher use: older guests (O.R. = 1.02,
p.05),
| snowboarders (O.R. = 3.24, p.05), guests with a college degree
(O.R. =
| 1.73, p.05), and those who spent more days on the mountain (O.R. =
| 3.18-8.03, p.05). Helmet use was significantly associated with less
| risky skiing/snowboarding (higher speeds, O.R. = 0.64, 95% C.I.
0.49,
| 0.82; more challenge, O.R. = 0.76, 95% C.I. 0.60, 0.97) compared to
no
| use. A minority reported engaging in more risky skiing/snowboarding
| (33.6% faster; 35.7% challenge), but this was associated with
variables
| other than helmet use.
|
| Conclusions: Helmet use by skiers and snowboarders continued to
trend
| upwards and does not appear to motivate more risk taking. Helmet
wearers
| engaged in less risk behavior than non-wearers, suggesting that
| decisions to adopt helmets are motivated by safety concerns. "
|
|
| The above data is very interesting because it actually demonstrates
risk
| compensation, but in this case it is those that show the highest
| perception of risk (and thus choose to wear a helmet) are also taking
| the least overall risks in the study.
|
| If there was no risk compensation involved with wearing helmets you
| would expect that there was no change in risk behaviour on wearing
| helmets. In fact what this study shows is that those who wear helmets
| also take less risks.

It is likely that risk compensation exists in some form or other,
sometimes cancelling itself out, sometimes working one way, sometimes
the other, in all activities. I suggested that with respect to
competition skiers when skiing for pleasure, or to mountain dwellers,
the factor of influence was likely to be negligible (helmet wearing).

I made a number of points to back this up, and challenged you on various
issues, but you have yet to respond.

In message
"pg" wrote:


"Mike Clark" wrote in message
.uk...
[snip]
|
| The above data is very interesting because it actually demonstrates
| risk compensation, but in this case it is those that show the
| highest perception of risk (and thus choose to wear a helmet) are
| also taking the least overall risks in the study.
|
| If there was no risk compensation involved with wearing helmets you
| would expect that there was no change in risk behaviour on wearing
| helmets. In fact what this study shows is that those who wear helmets
| also take less risks.

It is likely that risk compensation exists in some form or other,
sometimes cancelling itself out, sometimes working one way, sometimes
the other, in all activities. I suggested that with respect to
competition skiers when skiing for pleasure, or to mountain dwellers,
the factor of influence was likely to be negligible (helmet wearing).

I made a number of points to back this up, and challenged you on
various issues, but you have yet to respond.


I've responded several times on the particular question of helmet use
but you clearly haven't acknowledged my response from your
comments above.

The study you cite from the USA seems to suggest that those wearing
helmets are in fact overcompensating by in fact skiing with less risky
behaviour. In contrast I pointed out that the Norwegian study came to
the conclusion that those who regarded themselves as risk takers were
more likely to wear a helmet. It could be that this represents a real
difference between the study groups in the USA and Norway, or it could
mean that people who thought that they were risk takers, in fact
weren't.

On the specific question of mountain dwellers or competition skiers I've
acknowledged that no data seems to exist that would allow us to look at
the possibility of risk compensation in this group with regard to
helmets. To me it is an unanswered question that I do not claim to know
the answer to, whereas you seem to be happy in your belief
unsubstantiated with any numerical evidence.

On the wider issue of whether mountain dwellers and professional skiers
are safer skiers than the general population I suggest that the data
doesn't stand up to scrutiny. Clearly ski-racers take risks and do
suffer injuries at a rate that looks higher than recreational skiers.
Similarly if you look at things such as avalanche statistics you will
see that mountain dwellers and professional skiers, including guides and
instructors are highly represented in the records. Yes they do spend
more time in the mountains as individuals, but numerically they are
still a smaller number than the clients and other visitors so what is
the risk per skier day?

see
http://david.geraldine.club.fr/Piste...dents-2006.pdf


This article makes some interesting estimates on numbers skiing
off-piste and ski-touring. For example it estimates that of
7 million skiers skiing for fifty million skier days in France, 10-12%
of skiers are skiing off-piste (possibly as high as 50% in Tignes)
whereas there are estimated only 1 million ski-tourers in the whole of
the Alps. The estimate is that ski-tourers may be at 100 times the risk
of avalanche compared to off-piste skiers.

Clearly then if peoples skiing abilities lead them to make a transition
from piste skiing to off-piste skiing and onwards to ski-touring it
seems plainly obvious that an increase in skills and ability is leading
to an increased participation in riskier activities. That participation
in riskier activities is then leading to higher representation in the
accident figures.

Mike
--
o/ \\ // |\ ,_ o Mike Clark
\__,\\ // __o | \ / /\, "A mountain climbing, cycling, skiing,
" || _`\,_ |__\ \ | immunology lecturer, antibody engineer and
` || (_)/ (_) | \corn computer user"

In message k
Mike Clark wrote:

[snip]
see
http://david.geraldine.club.fr/Piste...dents-2006.pdf

should be

http://david.geraldine.club.fr/Piste...dents-2006.pdf


--
o/ \\ // |\ ,_ o Mike Clark
\__,\\ // __o | \ / /\, "A mountain climbing, cycling, skiing,
" || _`\,_ |__\ \ | immunology lecturer, antibody engineer and
` || (_)/ (_) | \corn computer user"

On Mon, 22 Jan 2007 16:32:50 -0000, "MoonMan"
wrote:

And it is obvious rubbish, people use safety equipment
to be safer, not so they can be more dangerous.. [Sorry champ I know you
deliberately do the opposite ]
/rant

Sure that wasn't aimed at me?

--
-Pip

On Mon, 22 Jan 2007 17:37:04 -0000, "MoonMan"
wrote:

You've made my point for me, How can people Risk Compensate? they have no
real knowledge of what risk is, for example many people (current company
excluded of course) think that if you are exposed to a "Cancer causing
chemical" you *will* get cancer,rather than increasing a hypothetical small
chance that you might get cancer, as you stated people think planes are
dangerous when they are in fact one of our safest forms of transport. So how
can you judge the exact amount a device makes you safer, then act exactly
that much (or actually acording to the theory slightly more) stupidly? it
just doesn't make sense.

Well, obviously, people compensate for the *perceived* change in risk,
so their compensation may actually have no bearing on the reality; in
the case of apparent reduced risk, they could "over compensate" in
reality, thus increasing the real world risk, or they could
under-compensate, in which case they're safer, entirely depending upon
their perception.

We all have our personal level of both 'perceived risk' and also
'acceptable risk'. I'd suggest that the first sets the scale, as it
were, and the second sets the point on that scale beyond which we as
individuals are not happy to go. The point is that the scale itself
may have only approximate bearing on the real risk.

It is in the nature of our society to make our lives safer and safer;
only in the discovery of a new technology or activity do the risks
usually increase. What I might baulk at now now might well have been
considered perfectly safe, or at least, "the way things are" a hundred
years ago.

When it comes to personal protection, I prefer to have the choice, but
I'm sure that over the years the (probably) well-meaning pressure to
increase helmet use will eventually force us, either through
legislation, or more likely, through the insidious pressure of
insurance, to wear helmets. Just let's not force the pace, eh?

Hopefully I'll be long gone before helmets are compulsory for
recreational skiing.

--
-Pip