Ongoing debate

http://www.guardian.co.uk/commentisf...helmets-safety

Interesting point if correct:-

"On the Australian experience, this from Stuart Jeffries in the Aug
2008 piece adds to your point:

When cycle helmets were made compulsory in Australia the number of
people cycling fell by a third, and although the number of serious
head injuries fell, too, it only fell by 11%. So, despite a large rise
in Australia in helmet use, the risk of head injury among those who
continued to cycle actually rose. Of course, one can't infer from this
that cycle helmets cause serious head injuries, but the statistical
association of a rise in both helmet use and in head injuries is
embarrassing for those who advocate helmets."

On Aug 12, 12:40*am, Squashme wrote:
http://www.guardian.co.uk/commentisf...ling-helmets-s...

Interesting point if correct:-

"On the Australian experience, this from Stuart Jeffries in the Aug
2008 piece adds to your point:

When cycle helmets were made compulsory in Australia the number of
people cycling fell by a third, and although the number of serious
head injuries fell, too, it only fell by 11%. So, despite a large rise
in Australia in helmet use, the risk of head injury among those who
continued to cycle actually rose. Of course, one can't infer from this
that cycle helmets cause serious head injuries, but the statistical
association of a rise in both helmet use and in head injuries is
embarrassing for those who advocate helmets."

Strange that once again a medical professional who deals with serious
head trauma cases on a regular basis thinks that cyclists should wear
helmets. If I may copy one interesting paragraph from this article:

"Until the government sees sense and decides to make the use of
helmets compulsory, the wearing of them needs to be encouraged as much
as possible by all, including the media – especially in these days of
reduced NHS budgets, when we need to reduce the burden on its
services. Many may question the effectiveness of helmets, but in 10
years in my current role I have never had a brain-injured patient who
was wearing a helmet – except for one boy who had neglected to do up
the straps"

This shows the importance of using safety equipment in the correct
manner. Maybe the Aussies didn't?

Derek C

On 12/08/10 05:11, Derek C wrote:
On Aug 12, 12:40 am, Squashme wrote:
http://www.guardian.co.uk/commentisf...ling-helmets-s...

Interesting point if correct:-

"On the Australian experience, this from Stuart Jeffries in the Aug
2008 piece adds to your point:

When cycle helmets were made compulsory in Australia the number of
people cycling fell by a third, and although the number of serious
head injuries fell, too, it only fell by 11%. So, despite a large rise
in Australia in helmet use, the risk of head injury among those who
continued to cycle actually rose. Of course, one can't infer from this
that cycle helmets cause serious head injuries, but the statistical
association of a rise in both helmet use and in head injuries is
embarrassing for those who advocate helmets."

Strange that once again a medical professional who deals with serious
head trauma cases on a regular basis thinks that cyclists should wear
helmets. If I may copy one interesting paragraph from this article:

"Until the government sees sense and decides to make the use of
helmets compulsory, the wearing of them needs to be encouraged as much
as possible by all, including the media – especially in these days of
reduced NHS budgets, when we need to reduce the burden on its
services. Many may question the effectiveness of helmets, but in 10
years in my current role I have never had a brain-injured patient who
was wearing a helmet – except for one boy who had neglected to do up
the straps"

I bet he never saw a serious head injury from anyone wearing a pink
feather boa either. You should wear one, will help prevent brain trauma.

This shows the importance of using safety equipment in the correct
manner. Maybe the Aussies didn't?

Derek C

On Aug 12, 6:21*am, Tosspot wrote:
On 12/08/10 05:11, Derek C wrote:

On Aug 12, 12:40 am, Squashme wrote:
http://www.guardian.co.uk/commentisf...ling-helmets-s....

Interesting point if correct:-

"On the Australian experience, this from Stuart Jeffries in the Aug
2008 piece adds to your point:

When cycle helmets were made compulsory in Australia the number of
people cycling fell by a third, and although the number of serious
head injuries fell, too, it only fell by 11%. So, despite a large rise
in Australia in helmet use, the risk of head injury among those who
continued to cycle actually rose. Of course, one can't infer from this
that cycle helmets cause serious head injuries, but the statistical
association of a rise in both helmet use and in head injuries is
embarrassing for those who advocate helmets."

Strange that once again a medical professional who deals with serious
head trauma cases on a regular basis thinks that cyclists should wear
helmets. If I may copy one interesting paragraph from this article:

*"Until the government sees sense and decides to make the use of
helmets compulsory, the wearing of them needs to be encouraged as much
as possible by all, including the media – especially in these days of
reduced NHS budgets, when we need to reduce the burden on its
services. Many may question the effectiveness of helmets, but in 10
years in my current role I have never had a brain-injured patient who
was wearing a helmet – except for one boy who had neglected to do up
the straps"

I bet he never saw a serious head injury from anyone wearing a pink
feather boa either. *You should wear one, will help prevent brain trauma.


A typical non-sequitur argument from a helmet sceptic! Do you know
what a red (or pink) herring is?

Excuse me, I must put my cycle helmet on as I am just about to wash my
hair!

By the way, according to some statistics supplied by another helmet
sceptic, only 2.5% of falls in the bathroom requiring hospital
treatment cause head injuries, whereas the comparative figure for
cyclists is 38%

On 12/08/2010 00:40, Squashme wrote:
http://www.guardian.co.uk/commentisf...helmets-safety

Interesting point if correct:-

"On the Australian experience, this from Stuart Jeffries in the Aug
2008 piece adds to your point:

When cycle helmets were made compulsory in Australia the number of
people cycling fell by a third, and although the number of serious
head injuries fell, too, it only fell by 11%. So, despite a large rise
in Australia in helmet use, the risk of head injury among those who
continued to cycle actually rose. Of course, one can't infer from this
that cycle helmets cause serious head injuries, but the statistical
association of a rise in both helmet use and in head injuries is
embarrassing for those who advocate helmets."


The only Australia figure I have seen is for the state of Victoria the
actual drop after in DSHI (Death Serious Head Injuries was 43%). I
believe the number of cyclist did initially plummet, by an average 30%
over the first two years. But AIUI this was only 15% less by the second
year.

The trouble seems to be that certain denialists (many well known to us)
repeatedly publish nonsence on this subject and the more gullible
amongst us read it and repeat it.

It would be interesting to see a justification for the above claim. But
I suspect that if it does appear it will suffer from one of the standard
problems related to scientific denial and the presentation of statistics.

Interpretting population statistics is fraught with difficulties and
unkonwns. The reason the denialists are so keen on them is that it gives
them an opportunity to confuse a mathematically weak public by
unjustifiablly converting this uncertainty into a negative result.

Nick wrote:

The only Australia figure I have seen is for the state of Victoria the
actual drop after in DSHI (Death Serious Head Injuries was 43%). I
believe the number of cyclist did initially plummet, by an average 30%
over the first two years. But AIUI this was only 15% less by the second
year.

So you haven't read (or bothered to look for) any of the research or the
data that is out there for many of the States in Australia and other
countries.....


The trouble seems to be that certain denialists (many well known to us)
repeatedly publish nonsence on this subject and the more gullible
amongst us read it and repeat it.

.....yet you already know its nonsense?

The biggest problem with the debate is uninformed twaddle from people
who already "know" the answer without bothering with such inconveniences
as the evidence.

Tony

On Thu, 12 Aug 2010 08:45:22 +0100 someone who may be Nick
wrote this:-

The only Australia figure I have seen is for the state of Victoria the
actual drop after in DSHI (Death Serious Head Injuries was 43%). I
believe the number of cyclist did initially plummet, by an average 30%
over the first two years. But AIUI this was only 15% less by the second
year.

http://www.cyclehelmets.org/1194.html has many more figures. The
discussion of the overall trend is

"The states with enforced laws at the time of the 1991 census (red
line on the graph below) saw a reversal of the trend of increasing
percentages of people cycling to work. In contrast, the percentage
cycling to work in states with no enforced helmet laws (blue line on
graph – WA, ACT and Qld) continued to increase, the sharp decline
occurring only in the 1996 census, when helmet laws were enforced
throughout Australia.

"There has been no recovery - the trend continued downward over the
next decade, followed by a slight increase in some states in the
2006 census as health authorities in some states try to counteract
increasing health problems, due to inactivity and obesity, by
increased promotion of cycling."

As for statistics, Dorre Robinson knows a little about them
http://www.cyclehelmets.org/papers/c2022.pdf. Hers are rather more
robust than those produced by helmet lobbyists, who are usually
quacks with little or no training in statistics.

Studying whole populations is not a trick to confuse the public. It
is a method which allows us to see what happens in the real world,
and check the claims made by enthusiasts who have made small scale
studies.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000...#pt3-pb3-l1g54

Squashme wrote:
http://www.guardian.co.uk/commentisf...helmets-safety

And a good letter in reply the next day:
http://www.guardian.co.uk/lifeandsty...without-helmet


Interesting point if correct:-

"On the Australian experience, this from Stuart Jeffries in the Aug
2008 piece adds to your point:

When cycle helmets were made compulsory in Australia the number of
people cycling fell by a third, and although the number of serious
head injuries fell, too, it only fell by 11%. So, despite a large rise
in Australia in helmet use, the risk of head injury among those who
continued to cycle actually rose. Of course, one can't infer from this
that cycle helmets cause serious head injuries, but the statistical
association of a rise in both helmet use and in head injuries is
embarrassing for those who advocate helmets."

Correct and cycling fell particularly hard in the under 16 age group -
up to 90% in some places. But the evidence is the same across Australia
and New Zealand that despite a large drop in cycle use, there was no
drop in head injury rates when helmets were made mandatory. The most
interesting one I saw and have to relocate was one of the Canadian
states where a helmet law was introduced but then not enforced. On the
introduction of the law helmet use doubled to around 90% usage and then
dropped back to the pre-law level over the next two years as the law was
not enforce. The trend line of cyclist head injuries is a straight line
right through that period, totally unperturbed by the big increase and
following big decrease in helmet usage.

Tony

Squashme wrote:

http://www.guardian.co.uk/commentisf...helmets-safety

Interesting point if correct:-

"On the Australian experience, this from Stuart Jeffries in the Aug
2008 piece adds to your point:

When cycle helmets were made compulsory in Australia the number of
people cycling fell by a third, and although the number of serious
head injuries fell, too, it only fell by 11%. So, despite a large rise
in Australia in helmet use, the risk of head injury among those who
continued to cycle actually rose. Of course, one can't infer from this
that cycle helmets cause serious head injuries, but the statistical
association of a rise in both helmet use and in head injuries is
embarrassing for those who advocate helmets."

Have you got a figure for the level of compliance with the law there?

The "discrepancy" might easily be explained in terms of the difference in
attitude and behaviours as between:

(a) those who are inclined to comply with the law and not to commit illegal
acts, and

(b) those who couldn't give a whatsername for any law or rules.

The ones "deterred" from cycling (eg, who won't cycle when a helmet is not
available) may well be those who were less likely to put themselves at risk,
whilst those who cycle without complying with that law might frequently put
themselves and others at unnecessary risk.

Tony Raven wrote:
Squashme wrote:
http://www.guardian.co.uk/commentisf...helmets-safety


And a good letter in reply the next day:
http://www.guardian.co.uk/lifeandsty...without-helmet



Interesting point if correct:-

"On the Australian experience, this from Stuart Jeffries in the Aug
2008 piece adds to your point:

When cycle helmets were made compulsory in Australia the number of
people cycling fell by a third, and although the number of serious
head injuries fell, too, it only fell by 11%. So, despite a large rise
in Australia in helmet use, the risk of head injury among those who
continued to cycle actually rose. Of course, one can't infer from this
that cycle helmets cause serious head injuries, but the statistical
association of a rise in both helmet use and in head injuries is
embarrassing for those who advocate helmets."

Correct and cycling fell particularly hard in the under 16 age group -
up to 90% in some places. But the evidence is the same across Australia
and New Zealand that despite a large drop in cycle use, there was no
drop in head injury rates when helmets were made mandatory. The most
interesting one I saw and have to relocate was one of the Canadian
states where a helmet law was introduced but then not enforced. On the
introduction of the law helmet use doubled to around 90% usage and then
dropped back to the pre-law level over the next two years as the law was
not enforce. The trend line of cyclist head injuries is a straight line
right through that period, totally unperturbed by the big increase and
following big decrease in helmet usage.

So what is the level of compliance with that law and what is the level of
breach of that law?

That missing data is relevant and essential to a proper understnding of the
results.