"judith" wrote in message
...
On Thu, 28 Aug 2008 15:01:43 +0100, "OG"
wrote:


"judith" wrote in message
. ..
On Thu, 28 Aug 2008 11:19:32 GMT, _
wrote:

snip


Indeed. It's just as important to protect it while cycling as to do so
while walking, or having a shower.

Do you wear a helmet while walking?

If not, why not?


I am not aware of any evidence that wearing a helmet whilst out
walking will overall reduce the risk of injury to my head.

I am aware that research has been carried out which shows that overall
wearing a helmet while cycling will reduce the risk of injury to the
head.


But can you point to evidence that overall wearing a helmet while cycling
'does' reduce the risk of injury to the head?


Yes - I think I got it from: British Medical Journal, (2006) 332:
722-725 "No clear evidence from
countries that have enforced the wearing of helmets" D.L. Robinson

but I didn't keep the copy.


Is this the one?
http://www.bmj.com/cgi/content/full/332/7543/722-a

There are 4 summary points,
- Case-control studies suggest cyclists who choose to wear helmets generally
have fewer head injuries than non-wearers

- Before and after data show enforced helmet laws discourage cycling but
produce no obvious response in percentage of head injuries

- This contradiction may be due to risk compensation, incorrect helmet
wearing, reduced safety in numbers, or incorrect adjustment for confounders
in case-control studies

- Governments should focus on factors such as speeding, drink-driving,
failure to obey road rules, poor road design, and cycling without lights at
night

Are you suggesting that this may not be correct?

Given the summary points, yes it seems your interpretation is incorrect.

And do you have any evidence that wearing a helmet whilst out walking
*does* overall reduce the risk of injury to my head.

? ? ?

On Thu, 28 Aug 2008 18:51:40 +0100, "OG"
wrote:
snip

Is this the one?
http://www.bmj.com/cgi/content/full/332/7543/722-a

There are 4 summary points,
- Case-control studies suggest cyclists who choose to wear helmets generally
have fewer head injuries than non-wearers

interesting points - but points which are irrelevant to "can you
point to evidence that overall wearing a helmet while cycling 'does'
reduce the risk of injury to the head? - snipped

Are you suggesting that this may not be correct?

Given the summary points, yes it seems your interpretation is incorrect.

Oh really - you missed the bit:

Helmeted cyclists in collision with motor vehicles had much less
serious non-head injuries than non-helmeted cyclists (suggesting lower
impact crashes).

I would say that that supports my view that overall wearing a helmet
while cycling 'does' reduce the risk of injury to the head? - wouldn't
you?


And do you have any evidence that wearing a helmet whilst out walking
*does* overall reduce the risk of injury to my head.

? ? ?


Ignore that bit - it was a response to a ****wit who was suggesting
pedestrians should wear helmets.

"judith" wrote in message
...
On Thu, 28 Aug 2008 18:51:40 +0100, "OG"
wrote:
snip

Is this the one?
http://www.bmj.com/cgi/content/full/332/7543/722-a

There are 4 summary points,
- Case-control studies suggest cyclists who choose to wear helmets
generally
have fewer head injuries than non-wearers

interesting points - but points which are irrelevant to "can you
point to evidence that overall wearing a helmet while cycling 'does'
reduce the risk of injury to the head? - snipped

Are you suggesting that this may not be correct?

Given the summary points, yes it seems your interpretation is incorrect.

Oh really - you missed the bit:

Helmeted cyclists in collision with motor vehicles had much less
serious non-head injuries than non-helmeted cyclists (suggesting lower
impact crashes).

That's just after the bit that notes that cyclists who *choose* to wear
helmets are of higher socioeconomic status - are you seriously claiming that
we can reduce poverty by forcing poor cyclists to wear helmets?

Tee hee, Norman Tebbit, eat your heart out!

I would say that that supports my view that overall wearing a helmet
while cycling 'does' reduce the risk of injury to the head? - wouldn't
you?

No. You have mis-read that part of the article! Cyclists who *choose* to
wear helmets suffer less serious *non-head* injuries - i.e. irrespective of
any protection offered by the helmet, it is suggested that they experience
lower impact accidents and the difference in seriousness of head injuries
*may* be explained by that factor.

That is what is described as a confounder, and as the paragraph concludes
"Unless case-control studies record and fully adjust for all these
confounders, their effects may incorrectly be attributed to helmets"

Didn't the article title give you a clue?

On Thu, 28 Aug 2008 21:05:17 +0100, "OG"
wrote:


"judith" wrote in message
.. .
On Thu, 28 Aug 2008 18:51:40 +0100, "OG"
wrote:
snip

Is this the one?
http://www.bmj.com/cgi/content/full/332/7543/722-a

There are 4 summary points,
- Case-control studies suggest cyclists who choose to wear helmets
generally
have fewer head injuries than non-wearers

interesting points - but points which are irrelevant to "can you
point to evidence that overall wearing a helmet while cycling 'does'
reduce the risk of injury to the head? - snipped

Are you suggesting that this may not be correct?

Given the summary points, yes it seems your interpretation is incorrect.

Oh really - you missed the bit:

Helmeted cyclists in collision with motor vehicles had much less
serious non-head injuries than non-helmeted cyclists (suggesting lower
impact crashes).

That's just after the bit that notes that cyclists who *choose* to wear
helmets are of higher socioeconomic status - are you seriously claiming that
we can reduce poverty by forcing poor cyclists to wear helmets?

Tee hee, Norman Tebbit, eat your heart out!

I would say that that supports my view that overall wearing a helmet
while cycling 'does' reduce the risk of injury to the head? - wouldn't
you?

No. You have mis-read that part of the article! Cyclists who *choose* to
wear helmets suffer less serious *non-head* injuries - i.e. irrespective of
any protection offered by the helmet, it is suggested that they experience
lower impact accidents and the difference in seriousness of head injuries
*may* be explained by that factor.

That is what is described as a confounder, and as the paragraph concludes
"Unless case-control studies record and fully adjust for all these
confounders, their effects may incorrectly be attributed to helmets"

Didn't the article title give you a clue?


No - because there is no mention of compulsion in the question I
posed:


and indeed, the following finding is very relevant:

"Helmeted cyclists in collision with motor vehicles had much less
serious non-head injuries than non-helmeted cyclists (suggesting lower
impact crashes).

A very simple statement- no ifs, buts, or may bes.

Do you not accept that statement?

What about the other points from the DfT paper I have quoted:

Bicycle helmets have been found to be effective at reducing the
incidence and severity of head, brain and upper facial injury.
Bicycle helmets have been found to be effective in reducing injury for
users of all ages, though particularly for children.
All studies found evidence of a protective effect with regards to head
injury of helmet wearing in the event of a bicycle crash.

do you not believe those either?

"judith" wrote in message
...
On Thu, 28 Aug 2008 21:05:17 +0100, "OG"
wrote:


"judith" wrote in message
. ..
On Thu, 28 Aug 2008 18:51:40 +0100, "OG"
wrote:
snip

Is this the one?
http://www.bmj.com/cgi/content/full/332/7543/722-a

There are 4 summary points,
- Case-control studies suggest cyclists who choose to wear helmets
generally
have fewer head injuries than non-wearers

interesting points - but points which are irrelevant to "can you
point to evidence that overall wearing a helmet while cycling 'does'
reduce the risk of injury to the head? - snipped

Are you suggesting that this may not be correct?

Given the summary points, yes it seems your interpretation is incorrect.

Oh really - you missed the bit:

Helmeted cyclists in collision with motor vehicles had much less
serious non-head injuries than non-helmeted cyclists (suggesting lower
impact crashes).

That's just after the bit that notes that cyclists who *choose* to wear
helmets are of higher socioeconomic status - are you seriously claiming
that
we can reduce poverty by forcing poor cyclists to wear helmets?

Tee hee, Norman Tebbit, eat your heart out!

I would say that that supports my view that overall wearing a helmet
while cycling 'does' reduce the risk of injury to the head? - wouldn't
you?

No. You have mis-read that part of the article! Cyclists who *choose* to
wear helmets suffer less serious *non-head* injuries - i.e. irrespective
of
any protection offered by the helmet, it is suggested that they experience
lower impact accidents and the difference in seriousness of head injuries
*may* be explained by that factor.

That is what is described as a confounder, and as the paragraph concludes
"Unless case-control studies record and fully adjust for all these
confounders, their effects may incorrectly be attributed to helmets"

Didn't the article title give you a clue?


No - because there is no mention of compulsion in the question I
posed:

So why bring it up? The issue is whether wearing a helmet (in itself) offers
head protection. Real life experience in areas where helmet wearing rates
have been increased does not offer a correlation between increased helmet
wearing rates and reduced head injury rates.


and indeed, the following finding is very relevant:

"Helmeted cyclists in collision with motor vehicles had much less
serious non-head injuries than non-helmeted cyclists (suggesting lower
impact crashes).

A very simple statement- no ifs, buts, or may bes.

Do you not accept that statement?

I accept the statement, but your attempt to use it in support of your
proposition is flawed.

There may be numerous reasons for lower impact crashes, and there may be a
correlation with the accidents experienced by helmet wearers, but it is
flawed logic that the wearing of a helmet in itself actively reduces the
impact of crashes

On Thu, 28 Aug 2008 22:40:52 +0100, "OG"
wrote:


"judith" wrote in message
.. .
On Thu, 28 Aug 2008 21:05:17 +0100, "OG"
wrote:


"judith" wrote in message
...
On Thu, 28 Aug 2008 18:51:40 +0100, "OG"
wrote:
snip

Is this the one?
http://www.bmj.com/cgi/content/full/332/7543/722-a

There are 4 summary points,
- Case-control studies suggest cyclists who choose to wear helmets
generally
have fewer head injuries than non-wearers

interesting points - but points which are irrelevant to "can you
point to evidence that overall wearing a helmet while cycling 'does'
reduce the risk of injury to the head? - snipped

Are you suggesting that this may not be correct?

Given the summary points, yes it seems your interpretation is incorrect.

Oh really - you missed the bit:

Helmeted cyclists in collision with motor vehicles had much less
serious non-head injuries than non-helmeted cyclists (suggesting lower
impact crashes).

That's just after the bit that notes that cyclists who *choose* to wear
helmets are of higher socioeconomic status - are you seriously claiming
that
we can reduce poverty by forcing poor cyclists to wear helmets?

Tee hee, Norman Tebbit, eat your heart out!

I would say that that supports my view that overall wearing a helmet
while cycling 'does' reduce the risk of injury to the head? - wouldn't
you?

No. You have mis-read that part of the article! Cyclists who *choose* to
wear helmets suffer less serious *non-head* injuries - i.e. irrespective
of
any protection offered by the helmet, it is suggested that they experience
lower impact accidents and the difference in seriousness of head injuries
*may* be explained by that factor.

That is what is described as a confounder, and as the paragraph concludes
"Unless case-control studies record and fully adjust for all these
confounders, their effects may incorrectly be attributed to helmets"

Didn't the article title give you a clue?


No - because there is no mention of compulsion in the question I
posed:

So why bring it up? The issue is whether wearing a helmet (in itself) offers
head protection. Real life experience in areas where helmet wearing rates
have been increased does not offer a correlation between increased helmet
wearing rates and reduced head injury rates.


I agree : The issue is whether wearing a helmet (in itself) offers
head protection.

I would say that the answer is yes.

my **** snipped

I accept the statement, but your attempt to use it in support of your
proposition is flawed.


You are right - I have retracted what I said - as I had not
appreciated the non-helmeted bit,

"judith" wrote in message
...
On Thu, 28 Aug 2008 22:40:52 +0100, "OG"
wrote:


"judith" wrote in message
. ..
On Thu, 28 Aug 2008 21:05:17 +0100, "OG"
wrote:


"judith" wrote in message
m...
On Thu, 28 Aug 2008 18:51:40 +0100, "OG"
wrote:
snip

Is this the one?
http://www.bmj.com/cgi/content/full/332/7543/722-a

There are 4 summary points,
- Case-control studies suggest cyclists who choose to wear helmets
generally
have fewer head injuries than non-wearers

interesting points - but points which are irrelevant to "can you
point to evidence that overall wearing a helmet while cycling 'does'
reduce the risk of injury to the head? - snipped

Are you suggesting that this may not be correct?

Given the summary points, yes it seems your interpretation is
incorrect.

Oh really - you missed the bit:

Helmeted cyclists in collision with motor vehicles had much less
serious non-head injuries than non-helmeted cyclists (suggesting lower
impact crashes).

That's just after the bit that notes that cyclists who *choose* to wear
helmets are of higher socioeconomic status - are you seriously claiming
that
we can reduce poverty by forcing poor cyclists to wear helmets?

Tee hee, Norman Tebbit, eat your heart out!

I would say that that supports my view that overall wearing a helmet
while cycling 'does' reduce the risk of injury to the head? - wouldn't
you?

No. You have mis-read that part of the article! Cyclists who *choose* to
wear helmets suffer less serious *non-head* injuries - i.e. irrespective
of
any protection offered by the helmet, it is suggested that they
experience
lower impact accidents and the difference in seriousness of head
injuries
*may* be explained by that factor.

That is what is described as a confounder, and as the paragraph
concludes
"Unless case-control studies record and fully adjust for all these
confounders, their effects may incorrectly be attributed to helmets"

Didn't the article title give you a clue?


No - because there is no mention of compulsion in the question I
posed:

So why bring it up? The issue is whether wearing a helmet (in itself)
offers
head protection. Real life experience in areas where helmet wearing rates
have been increased does not offer a correlation between increased helmet
wearing rates and reduced head injury rates.


I agree : The issue is whether wearing a helmet (in itself) offers
head protection.

I would say that the answer is yes.


So let's get back to the proposition.
If it were true that wearing a helmet offers protection; increasing helmet
usage would increase the number of people protected and reduce the incidence
of head injuries.

Do you agree that the paper points out that the 'expected' reduction in head
injuries has not been observed?

On Thu, 28 Aug 2008 23:09:15 +0100, "OG"
wrote:


"judith" wrote in message
.. .
On Thu, 28 Aug 2008 22:40:52 +0100, "OG"
wrote:


"judith" wrote in message
...
On Thu, 28 Aug 2008 21:05:17 +0100, "OG"
wrote:


"judith" wrote in message
om...
On Thu, 28 Aug 2008 18:51:40 +0100, "OG"
wrote:
snip

Is this the one?
http://www.bmj.com/cgi/content/full/332/7543/722-a

There are 4 summary points,
- Case-control studies suggest cyclists who choose to wear helmets
generally
have fewer head injuries than non-wearers

interesting points - but points which are irrelevant to "can you
point to evidence that overall wearing a helmet while cycling 'does'
reduce the risk of injury to the head? - snipped

Are you suggesting that this may not be correct?

Given the summary points, yes it seems your interpretation is
incorrect.

Oh really - you missed the bit:

Helmeted cyclists in collision with motor vehicles had much less
serious non-head injuries than non-helmeted cyclists (suggesting lower
impact crashes).

That's just after the bit that notes that cyclists who *choose* to wear
helmets are of higher socioeconomic status - are you seriously claiming
that
we can reduce poverty by forcing poor cyclists to wear helmets?

Tee hee, Norman Tebbit, eat your heart out!

I would say that that supports my view that overall wearing a helmet
while cycling 'does' reduce the risk of injury to the head? - wouldn't
you?

No. You have mis-read that part of the article! Cyclists who *choose* to
wear helmets suffer less serious *non-head* injuries - i.e. irrespective
of
any protection offered by the helmet, it is suggested that they
experience
lower impact accidents and the difference in seriousness of head
injuries
*may* be explained by that factor.

That is what is described as a confounder, and as the paragraph
concludes
"Unless case-control studies record and fully adjust for all these
confounders, their effects may incorrectly be attributed to helmets"

Didn't the article title give you a clue?


No - because there is no mention of compulsion in the question I
posed:

So why bring it up? The issue is whether wearing a helmet (in itself)
offers
head protection. Real life experience in areas where helmet wearing rates
have been increased does not offer a correlation between increased helmet
wearing rates and reduced head injury rates.


I agree : The issue is whether wearing a helmet (in itself) offers
head protection.

I would say that the answer is yes.


So let's get back to the proposition.
If it were true that wearing a helmet offers protection; increasing helmet
usage would increase the number of people protected and reduce the incidence
of head injuries.

Do you agree that the paper points out that the 'expected' reduction in head
injuries has not been observed?


Yes - it is an anomaly which has not been explained.
I have said that when discussing the "compulsory" aspects there appear
to be anomalies which aren't adequately explained.

Have a look at
http://www.bmj.com/cgi/eletters/332/7543/722-a#15405


and then explain your interpretation of Figure 2



--

If you're going to make snide insinuations about the author,
as you undoubtedly did, then you can **** right off. (Guy Chapman)
If you are going to make accusations about someone, then you need to
be able to substantiate when asked to. (Judith Smith)

"judith" wrote in message
...
On Thu, 28 Aug 2008 23:09:15 +0100, "OG"
wrote:


"judith" wrote in message
. ..
On Thu, 28 Aug 2008 22:40:52 +0100, "OG"
wrote:


"judith" wrote in message
m...
On Thu, 28 Aug 2008 21:05:17 +0100, "OG"
wrote:


"judith" wrote in message
news:0cudb45nhac2m8af8m1oo46j077epj5otq@4ax. com...
On Thu, 28 Aug 2008 18:51:40 +0100, "OG"
wrote:
snip

Is this the one?
http://www.bmj.com/cgi/content/full/332/7543/722-a

There are 4 summary points,
- Case-control studies suggest cyclists who choose to wear helmets
generally
have fewer head injuries than non-wearers

interesting points - but points which are irrelevant to "can you
point to evidence that overall wearing a helmet while cycling 'does'
reduce the risk of injury to the head? - snipped

Are you suggesting that this may not be correct?

Given the summary points, yes it seems your interpretation is
incorrect.

Oh really - you missed the bit:

Helmeted cyclists in collision with motor vehicles had much less
serious non-head injuries than non-helmeted cyclists (suggesting
lower
impact crashes).

That's just after the bit that notes that cyclists who *choose* to
wear
helmets are of higher socioeconomic status - are you seriously
claiming
that
we can reduce poverty by forcing poor cyclists to wear helmets?

Tee hee, Norman Tebbit, eat your heart out!

I would say that that supports my view that overall wearing a helmet
while cycling 'does' reduce the risk of injury to the head? -
wouldn't
you?

No. You have mis-read that part of the article! Cyclists who *choose*
to
wear helmets suffer less serious *non-head* injuries - i.e.
irrespective
of
any protection offered by the helmet, it is suggested that they
experience
lower impact accidents and the difference in seriousness of head
injuries
*may* be explained by that factor.

That is what is described as a confounder, and as the paragraph
concludes
"Unless case-control studies record and fully adjust for all these
confounders, their effects may incorrectly be attributed to helmets"

Didn't the article title give you a clue?


No - because there is no mention of compulsion in the question I
posed:

So why bring it up? The issue is whether wearing a helmet (in itself)
offers
head protection. Real life experience in areas where helmet wearing
rates
have been increased does not offer a correlation between increased
helmet
wearing rates and reduced head injury rates.


I agree : The issue is whether wearing a helmet (in itself) offers
head protection.

I would say that the answer is yes.


So let's get back to the proposition.
If it were true that wearing a helmet offers protection; increasing helmet
usage would increase the number of people protected and reduce the
incidence
of head injuries.

Do you agree that the paper points out that the 'expected' reduction in
head
injuries has not been observed?


Yes

Thanks.

On Thu, 28 Aug 2008 21:05:17 +0100, "OG"
said in :

You have mis-read that part of the article! Cyclists who *choose* to
wear helmets suffer less serious *non-head* injuries

While this appears to be true in general, the largest statistical
study (Rodgers, 1988) showed that helmeted cyclists experienced a
small but not significant increased risk of injury and a small and
significant increase in risk of fatality.

I'd be interested to see if rabbits' feet or St Christopher medals
provide similar effects, but I don't suppose anyone has the
financial incentive to prove that particular case.

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

85% of helmet statistics are made up, 69% of them at CHS, Puget Sound