BMA page updated

The BMA "report" on which the change of policy was founded has been
amended. http://www.bma.org.uk/ap.nsf/Content/Cyclhelmet

Note that the policy is now on very shaky ground, since it is based on
a report whose inaccuracy has led to its being, in effect, withdrawn.

Note, too, that it now repeats Angie's assertion that the drop in
cycling in Australia was attributable to a change in the age for
driving. Or rather, as it turns out, a change in the age for
learner's permits, by one year, in one state.

It would be good to put pressure on to get the more egregious bull****
in the revised version pulled down - if they have to do it enough
times they may decide to stop letting Nicky Jaysinghe make them look
like a bunch of arses and get someone to do the job properly...


Guy
--
http://www.chapmancentral.co.uk

"To every complex problem there is a solution which is
simple, neat and wrong" - HL Mencken

"Just zis Guy, you know?" wrote in message
...
The BMA "report" on which the change of policy was founded has been
amended. http://www.bma.org.uk/ap.nsf/Content/Cyclhelmet

Note that the policy is now on very shaky ground, since it is based on
a report whose inaccuracy has led to its being, in effect, withdrawn.

Note, too, that it now repeats Angie's assertion that the drop in
cycling in Australia was attributable to a change in the age for
driving. Or rather, as it turns out, a change in the age for
learner's permits, by one year, in one state.

It would be good to put pressure on to get the more egregious bull****
in the revised version pulled down - if they have to do it enough
times they may decide to stop letting Nicky Jaysinghe make them look
like a bunch of arses and get someone to do the job properly...

Thanks Guy, this is the biggest crock of bull**** it has ever been my
misfortune to read. I copied a few quotes to illustrate:

"Recent evidence has indicated that the introduction of compulsory
legislation does not have a significant negative effect on cycling levels.
Such legislation in the UK should not discourage cyclists and lead to a more
sedentary lifestyle with consequent health risks.

It is estimated that 90,000 road-related and 100,000 off-road related
cycling accidents occur every year in the UK, of which 53% (100,000) involve
children under sixteen [Go to reference 4].

[4] Chapman HR, Curran ALM. Bicycle Helmets 1- Does the dental profession
have a role in promoting their use? British Dental Journal
2004;196(9):555-560

In 2002, 594 children and 1,801 adults were killed or seriously injured as a
result of road-related cycling accidents [Go to reference 6].

Action to reduce the high rate of fatal and serious accidents suffered by
cyclists must include: "

Enuff. Don't doctors suffer from embarrassment? The only possible
conclusion is that the people proposing this are either completely
incompetent to do any kind of research whatsoever, or they are higly
prejudiced.

If I belonged to an organisation which didn't immediately rectify such gross
errors, either the people in charge wouldn't have a job any more, or I
wouldn't be a member. Kind of makes you think about what the average doctor
is really like. Are they really happy to tolerate such behaviour in their
name?

Maybe it's time to try alternative medicine :-)

Rich wrote:

Enuff. Don't doctors suffer from embarrassment? The only possible
conclusion is that the people proposing this are either completely
incompetent to do any kind of research whatsoever, or they are higly
prejudiced.

I think it's technically known as a stitch-up, something surgeons in
particular should be good at.

--
Dave...

On Wed, 02 Mar 2005 23:06:52 GMT, "Rich"
wrote:

Thanks Guy, this is the biggest crock of bull**** it has ever been my
misfortune to read.

I thought so too. This is my reaction thus far - not sure what I'm
going to do with it yet.



I am inclined to the view that there may be a fundamental weakness in
the process by which this report has been prepared and amended: the
author(s) appear so intent on proving a point that they are accepting
at face value claims which anybody active in the field of cycle safety
will readily identify as speculative, contentious, or even plain
false.

I note that some of the more easily disproved information has been
removed, but there are still false claims which are readily
identifiable as emanating from the same source as the bizarre "50
fatalities" figure which has, at least, been removed. No attempt has
apparently been made to verify these claims, despite this previous and
plainly embarrassing experience. Moreover, it is apparent that the
authors of the paper not only have not read the wider literature, it
appears they have not even read the sources they cite - claims are
attributed to one source when that source is in turn citing another
already referenced within the BMA paper. This is appallingly sloppy!

A paper on which a body as prestigious as the BMA intends to base
lobbying for public policy change should at the very least meet the
standards required for publication in a journal such as the BMJ. I
strongly suspect that if this paper were submitted to the Editors it
would be rejected out of hand, and certainly following peer review.
The scope of research is narrow, the sources highly selective and
taken in the main from helmet compulsion activists. Context is almost
entirely absent. What is the evidential basis for singling out
cycling as a candidate for special treatment in this way? By what
measures is cycling either uniquely dangerous or uniquely productive
of head injuries? The authors do not say.
In short, the paper reads like a press release from the national
association of hand-wringers fine as an opinion piece, but lousy
science and an appalling basis for policy in any body with claims to
scientific credibility. It falls a very long way short of the breadth
and depth of the previous review which it apparently replaces. In
short, it does the BMA no credit to replace a policy based on a review
by the internationally renowned Meyer Hillman, with one based on a
document whose authors are not even identified by name, and who
display in several areas a profound ignorance of the current state of
knowledge on cycle safety.

The paper says: "The evidence from those countries where compulsory
cycle helmet use has already been introduced is that such legislation
has a beneficial effect on cycle-related deaths and head injuries."
This is not true: the facts from Australia and New Zealand, for
example, show that the laws were followed by a steep decline in the
numbers of cyclists, and consequently the *numbers* of head injuries
dropped, but the *rates* (per mile travelled or as a proportion of all
reported cyclist injuries) remained the same or worsened. If the
evidence were as clear-cut as is claimed, Road Safety Minister David
Jamieson would surely not have stated, as he did in a letter to
Michael Jack, MP, that the British Government knows of no data linking
increases in helmet use with improvements in cycling safety.

The paper says: "Recent evidence has indicated that the introduction
of compulsory legislation does not have a significant negative effect
on cycling levels." This refers solely to the situation in a single
province of Canada, where the law was not enforced. Wearing rate
trends did not change as a result of legislation - and neither did
head injury rate trends. This has been pointed out before, I believe,
but remains in the report; discussion of this "recent data" has been
placed separately at the end of the paper, which has the effect of
obscuring the source.

The paper says: "Such legislation in the UK should not discourage
cyclists and lead to a more sedentary lifestyle with consequent health
risks." But the BMA appears to want an enforced law, and the evidence
from jurisdictions where a law has been enforced strongly supports the
idea that cycling is discouraged.

The paper says: "Cycle helmets are now compulsory in Australia, New
Zealand, Spain, (etc.)" While true, this does not constitute
evidence. Some 75% of countries have laws requiring one to drive on
the right, not the left as we do. Does that mean we must follow suit?

To constitute evidence in favour of helmets the list of "law"
countries must be measured against the following criteria:

(1) Do these countries have, as a result of their laws or otherwise, a
safer cycling record than the UK?

(2) Did these countries demonstrate an improvement in cyclist safety
as a result of these laws?

The answer to 1 is: no. One example of a country with a markedly
better cycling safety record than the UK is the Netherlands. They
have a legislative framework for cyclist safety, but in their case it
is a law of "strict liability" where any motorist injuring a
vulnerable road user (pedestrian or cyclist) is presumed to be at
fault. This, unlike helmet laws, goes to the heart of the source of
danger, rather than attempting to mitigate the effects of it, and it
benefits pedestrians as much as it does cyclists. The BMA should not
need to be reminded that the major cause of injury death in children
is road traffic crashes, and only a small minority of these involve
bicycles.

The answer to 2, according to the British Government (and most
impartial observers) is also no, but to an extent it depends on your
definition of improvement. As stated above, while both Australia and
New Zealand saw numerical declines in cyclist head injuries following
the passage of laws, these were more than matched by declines in
numbers cycling (whether or not one accepts that these were due to the
laws) and in neither case did the injury rate drop. Graphs of
percentage head injury in New Zealand show that the decline in cyclist
head injury percentage tracks that of all road users for the five
years before and after the law, years during which head injury rates
rose from around 40% to over 95%, and then fell again to just over
90%. There is, in short, no credible evidence that the New Zealand
law (to name but one) has delivered any benefit.

Even if pre-existing trends and trends for non-cyclists are ignored,
so the results of all safety improvement for cyclists are attributed
solely to helmets, the laws in New Zealand still resulted in less than
a quarter of the injury reduction claimed in advance - cost-benefit
analysis indicates that the law, even attributing far more benefit to
helmets than can reasonably be proven, represented a net cost to the
economy.

The paper says "Studies in a number of these countries have shown that
high usage rates of helmets as a result of legislation is associated
with a reduction in cycle related deaths and head injuries." Really?
According to the US Consumer Products Safety Commission, the risk of
head injury has approximately doubled during the period when helmet
use rose from under 20% to around 50%. Perhaps the author means "some
studies" - in which case these should be named, and, given that BMA is
supposedly an impartial and professional body, balanced by those which
tell a conflicting story. Such as Rodgers' 1987 study of eight
million cycle injuries, which showed that helmet wearers were
significantly more likely to suffer a fatal accident than non-wearers.

The paper says "Evidence supporting the wearing of cycle helmets
continues to mount.". Really? The majority of the published original
research into helmets predates the BMA's last review, in 1997, and
what has been published since is predominantly meta-analysis. There
are a few genuinely new pieces of evidence, such as the 2004 paper by
Mok et. al in Injury Prevention, which showed that risk compensation
could be detected in the use of protective equipment (specifically
including cycle helmets) by children - a point which the paper ignores
entirely.

The paper says "It is estimated that 90,000 road-related and 100,000
off-road related cycling accidents occur every year in the UK, of
which 53% (100,000) involve children under sixteen". The cited
reference is a secondary source, the original being the paper's own
reference 5, and here the figure is revealed as speculative, with no
source cited. There is no measure of the severity of these injuries,
no reference to the causes (whether single-vehicle or involving motor
traffic, and no indication of the rate of injuries as a proportion of
all cyclist crashes. My own analysis of hospital admissions data for
children in England over a seven year period leads me to conclude that
the proportion of admissions in child cyclists which are due to head
injury is typical for all injury admissions, somewhat lower than for
child pedestrians. The paper makes no attempt to place the figures in
context, or to provide any measure of how these figures might compare
with, say, injuries due to trips and falls, which account for half of
all child injury admissions. Cycling accounts for around 6.5% of
serious child head injuries, and many of these will involve motor
traffic. 75% of children have bicycles.

The paper says: "In 2002, 594 children and 1,801 adults were killed or
seriously injured as a result of road-related cycling accidents."
While this may be true, the paper is surely not seeking to claim that
cycle helmets are effective in crashes involving motor traffic? This
is a wholly unsupportable idea, as even the most cursory reference to
the standards will reveal, yet what other purpose can there be in
mentioning the figure? I also wonder why were the 2003 figures not
used? And what about the 2,828 child and 5,644 adult pedestrians
killed or seriously injured the same year? In this context surely the
law to be pressed for is again that of presumed fault in crashes
involving vulnerable road users, which would yield benefits in a much
larger target group. The KSI figure for child cyclists in 2002 is
about the same as that for bus users - does the BMA think that bus
travel is especially dangerous?

The paper states: "Significantly, with child cyclists, 85 per cent of
accidents occur off road where primary prevention measures such as
cycle lanes, vehicle speed reduction and driver education are
ineffective" and cites as evidence a paper written by the Lee and Mann
of the Bicycle Helmet Initiative Trust, a single-issue pressure group
(the group responsible for the 50 fatalities claim and other
speculations). Published criticisms of this paper have also
apparently not been followed up.

The paper then goes on to cite some of the research which is routinely
quoted by helmet advocates, without noting (a) how the claimed figures
compare with the average for all claims made in such studies (i.e.
have the largest claims been cherry-picked?); (b) what, if any,
published criticisms exist of these studies; (c) how these studies
relate to real-world comparisons of helmet usage and head injury
trends, and what evidence might there be to explain the obvious
disparity. The absence of (3) is partly explained by the failure of
this paper even to mention this disparity, despite its having been
noted in the academic press at least as far back as 1987, and widely
discussed as a result of the 2004 Private Member's Bill introduced by
Eric Martlew, MP.

The paper cites reference 5 as the source for "a 30-month study of
3,854 cyclists showed that helmet usage decreased the overall risk of
brain injury by 65 per cent and severe brain injury by 74 per cent in
all age groups". This is a secondary source, the original is cited -
it comes from the Snell Memorial Foundation, which has a vested
interest in helmet promotion. Was the reference not checked?

The paper's reference 7 states "An Australian study showed that
wearing cycle helmets reduces both the incidence of facial injuries by
28 per cent and their severity" - this is another second-hand
reporting of a study which proposes no mechanism by which helmets
might prevent facial injuries; this might well be taken by a more
sceptical reviewer as evidence of confounding factors or
self-selection bias in the sample (a factor common to many
widely-reported observational studies, not by any means restricted to
cycle helmets). Instead it is repeated verbatim, but not referenced
back to its source.

The paper states: "A Cochrane review considering five case-control
studies from the UK, Australia and the USA illustrates a large and
consistent protective effect from cycle helmets, reducing the risk of
head and brain injury by 65 to 88 per cent and injury to the upper and
mid face by 65 per cent". This is unforgivably lax. The review in
question includes, by the nature of the Cochrane review, the comments
and criticisms which have been appended over time. None of these are
noted. Specifically, the 88% figure is quoted despite its having been
arrived at by attributing to helmets the differences in injury rates
between predominantly white middle-class families riding on leisure
trails, with mainly young, black, urban road cyclists. It has also
been pointed out that substituting the helmet wearing rate from this
homogeneous and atypical control group for co-author Rivara's own
contemporaneous street counts, brings the claimed benefit down to zero
within the limits of statistical accuracy. The Cochrane review has
also been criticised because the majority of cases covered come from
the authors' own studies, the studies selected all lie at the upper
end of the range of estimates of efficacy, and counter-evidence such
as that available from Australia and New Zealand by that time was
deliberately excluded.

The paper states: "A study of primary school, secondary school and
adult cyclists in New Zealand demonstrated a 19 per cent reduction in
head injuries to cyclists in the three years after the introduction of
legislation". This cites the work of Scuffham, directly contradicted
by the same author's own previous analysis which showed no benefit.
The change from no benefit to 19% benefit (well below the forecasts
and the estimates in the Cochrane review, a fact for which the paper
makes no attempt to account) was arrived at by the simple expedient of
careful selection of the timeframe, and explicit exclusion of
pre-existing trends. This same author has shown that even with this
claimed 19% benefit, the costs of the law still outweigh the benefits.

The paper states: "In Victoria, Australia, an increase in helmet use
from 31 per cent prior to legislation to 75 per cent one year after
was accompanied by a decrease in head injuries by 40 per cent in the
following four years". This is meaningless without the accompanying
data for pedestrians and other road users, and data for exposure. In
fact there was no evidence of any reduction in the proportion of head
injuries, the number of head injuries per cyclist, or the number of
head injuries per mile travelled. Levels of cycling dropped
substantially in the years following the law, by an amount at least as
great as the decline in head injuries. This has been sufficiently
widely discussed that to claim a 40% reduction in head injuries
without acknowledging the parallel reduction in cycling levels amounts
either to gross ignorance (in which case what are these authors doing
writing a policy paper in the first place) or deliberate intent to
mislead.

The paper states: "As with any other legislation enforcement is as
important as the law itself. Without compliance the law is at best
ineffective. To achieve maximum compliance, the legislation should be
complemented by mass educational and promotional campaigns. Evidence
from Australia and New Zealand showed that educational campaigns prior
to the introduction of legislation resulted in an increase in helmet
wearing from two per cent to up to 95 per cent". So it may have done,
but as previously noted it made no measurable difference to head
injury rates. If the goal of legislation is to promote helmet wearing
then the laws succeeded; if it is to reduce head injuries, then they
appear to have failed. If the aim is to deliver, overall, better
health for the nation, then it is clear to me that the helmet laws are
a public health own-goal, a fact now admitted by Australia's Land
Transportation Safety Board, the body responsible for the laws.

The paper cites: "An education programme in Reading that promoted
cycle helmet use among children and teenagers resulted in a local
increase in usage from 18 per cent to 60 per cent and a concurrent
decrease in cycle-related injuries". This is the Lee and Mann paper
in Arch. Dis. Child again, which appears to be the source of around
half the claims made in the paper. The authors' vested interest is
not noted, and neither are the criticisms of this paper for example,
there were no measures of levels of cycling to determine potential
deterrent effect, despite evidence from TRL that this was a possible
consequence which should therefore be controlled for; and the fact
that much of the claimed reduction in head injuries turns out to have
happened before the programme started. In fact this paper provides so
little hard data that it is impossible to test the authors'
conclusions.

The paper cites again the Cochrane review, criticisms of which are
previously noted. Again no account is taken of the criticisms and
comments which form part of that review.

The paper states: "At a practical level, enforcing the legislation can
be achieved through on-the-spot fines or tickets issued by police and
traffic wardens, while schools can ensure all children wear helmets on
journeys to and from school. Cycle helmet legislation and other safe
cycling promotions are not mutually exclusive, and there is a clear
role for the simultaneous introduction of more primary prevention
measures including cycle lanes, driver education and vehicle speed
reduction initiatives." No evidence is presented regarding the
relative merit of various "safe cycling" promotions, but international
evidence for the efficacy of cycle facilities in reducing the danger
posed to cyclists by motor traffic is hard to come by. John Franklin,
widely acknowledged as Britain's foremost authority on safe cycling,
has spent some time analysing the injury and fatality record of
segregated facilities and concluded that, in the main, they are
ineffective in their stated aim of reducing risk, since they generally
trade a reduction in a small risk (being hit from behind) for a
substantial increase in a much larger risk (conflicts at junctions).
To lump cycle facilities in as a "safe cycling" initiative is to
display an ignorance of the wider context which is, again,
unforgivable in a policy paper for a body as influential as the BMA.

The paper states: "The BMA believes that cycling has many advantages
to the individual in terms of improved health and mobility, as well as
to society via, for example, reduced air pollution and traffic
congestion. Even in the current hostile traffic environment, the
benefits gained from regular cycling are likely to outweigh the loss
of life through accidents for regular cyclists." This is
uncontroversial, but hardly compatible with the vastly inflated claims
of danger, and of helmet efficacy, made elsewhere. If the figures as
presented in the paper are taken at face value, helmets might be
expected to prevent of the order of 100,000 or more head injuries
annually, and by implication several thousands of serious,
debilitating or fatal injuries. This suggests that either the wording
"many advantages" is an understatement of the highest order, or the
figures are simply wrong.

The paper suggests a number of possible cycle safety initiatives. No
attempt is made to prioritise these, or to provide any measure of the
likely benefit. In context, a poll of the BMA's own members placed
helmets last in the hierarchy of possible effectiveness of various
measures. Indeed, I am not aware of any objective assessment of the
relative merits of various cycle safety interventions which puts
helmets anywhere other than last. And rightly so: prevention of
injury certainly does not begin with attempts to mitigate the last
link in the chain, when the cyclist hits the ground.

And that is my biggest problem with the tone of the entire paper.
Helmet laws seek to place the focus entirely on the cyclist, and on
passive actions taken by the cyclist to mitigate the consequences of
crashes. The causes of crashes are ignored, as are the potential
effects of addressing those causes on other road users. The paper
mentions, in passing, reduction of vehicle speeds. It has been
estimated that a reduction of mean vehicle speeds by 10mph could save
over 1,000 lives annually. By comparison, the most optimistic
credible estimate I have seen for the number of children's lives which
could be saved by a rigidly enforced helmet law is: one.

When we consider public policy in respect of cycling, we should be
thinking: do we emulate the USA and Australia, whose cycle safety
record is worse than our own (and who are, possibly not
coincidentally, the two most obese nations on Earth), or the
Netherlands?

The paper repeats a claim which comes from Angela Lee of the Bicycle
Helmet Initiative Trust that: "[...] evidence from Australia
indicating that cycling levels decreased following the introduction of
legislation [...] was found to be outdated and contained distortions
from variables including a reduction in the legal age of driving that
meant more teenagers travelled in motor vehicles." This is simply
wrong. The legal age for a learner driver's permit (not a licence)
was changed by one year in one state. This could not account for more
than a fraction of the observed drop in cycling levels nationally
among this age group, let alone made any significant impact on the
overall numbers cycling. The paper goes on to say: "A study from
Ontario, Canada, demonstrated that the introduction of helmet
legislation did not reduce numbers of children cycling" - this , as
has been pointed out, is because the law was not enforced - and
cycling levels were, in any case, poorly and inconsistently measured.
Lack of enforcement meant that wearing rates did not change after
passage of the law, as they did in New Zealand and Australia, so this
evidence, limited as it is, does not contradict that of the far more
closely studied Australasian laws.

The paper states: "Research published in June 2003 for the Department
for Transport revealed a growing trend for wearing cycle helmets in
the UK." Up to a point. Wearing rates were declining for children,
the group said to be most deserving of compulsion.

The paper does not note the apparent substantial reduction in cyclist
injuries in London following the introduction of the congestion
charge, against a background of increasing cycle use.

Finally, the references are appallingly narrow. I do not have access
to a tiny fraction of BMA's resources but my personal database of
helmet and cycle safety research publications amounts to several
hundred papers and abstracts, and with comments and critiques almost a
thousand separate documents.

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

88% of helmet statistics are made up, 65% of them at CHS, Puget Sound

It would be good to put pressure on to get the more egregious bull****
in the revised version pulled down - if they have to do it enough
times they may decide to stop letting Nicky Jaysinghe make them look
like a bunch of arses and get someone to do the job properly...

email to (as advised by the site)

Can you tell me why you are peddling (excuse the pun) this rubbish
about compulsory helmet use for cyclists?

Is there really any substantive evidence that helmets save lives? I
was involved in a RTA 14 months ago where an uninsured driver ploughed
into the back of me whilst I rode home from work, a journey that I had
done for some 3 years without incident and without a helmet.
According to anecdotal and "scientific" arguments I should not have
survived this 40mph impact as I was not wearing a helmet.

There are so many other things that would make cycling safer, such as
reminding drivers to take regular eye tests (the driver that run me
down actually told the police in her statement that she did not
realise that she had hit me) or educating drivers to be more tolerant
of vunerable road users including horse riders, cyclists and
motorcyclists.

Please stop this call for compulsion, the last thing we need in this
country is more pointless, uneforceable and widely ignored laws.

Allan Wishart

Just zis Guy, you know? wrote:


The answer to 2, according to the British Government ..... years during which head injury rates
rose from around 40% to over 95%, and then fell again to just over
90%. There is, in short, no credible evidence that the New Zealand
law (to name but one) has delivered any benefit.


ITYM helmet wearing rates.

Tony

in message , Just zis Guy,
you know? ') wrote:

Bravo. Only one nitpick: the bracket in this paragraph does not appear
to be closed.

ThereÂ*isÂ*noÂ*measureÂ*ofÂ*theÂ*severityÂ*ofÂ*the seÂ*injuries,
no reference to the causes (whether single-vehicle or involving motor
traffic, and no indication of the rate of injuries as a proportion of
all cyclist crashes.Â*Â*MyÂ*ownÂ*analysisÂ*ofÂ*hospitalÂ*admis sionsÂ*dataÂ*for
children in England over a seven year period leads me to conclude that
the proportion of admissions in child cyclists which are due to head
injury is typical for all injury admissions, somewhat lower than for
child pedestrians.Â*Â*TheÂ*paperÂ*makesÂ*noÂ*attemptÂ*to Â*placeÂ*theÂ*figuresÂ*in
context, or to provide any measure of how these figures might compare
with, say, injuries due to trips and falls, which account for half of
all child injury admissions.Â*Â*CyclingÂ*accountsÂ*forÂ*aroundÂ*6.5 %Â*of
serious child head injuries, and many of these will involve motor
traffic.Â*Â*75%Â*ofÂ*childrenÂ*haveÂ*bicycles.

--
(Simon Brooke) http://www.jasmine.org.uk/~simon/

Morning had broken. I found a rather battered tube of Araldite
resin in the bottom of the toolbag.

I thought so too. This is my reaction thus far - not sure what I'm
going to do with it yet.

Just skimmed through it. Reads very well - much more interesting than the
stuff I should have been reading this morning.

[para 4]
Road Safety Minister David Jamieson would surely not have stated, as he
did in a letter to Michael Jack, MP, that the British Government knows
of no data linking increases in helmet use with improvements in
cycling safety.

Would the government still claim this?

[para 8]
"head injury rates rose from around 40%.." should be helmet wearing rates.

[para 9]
Even if pre-existing trends and trends for non-cyclists are ignored,
so the results of all safety improvement for cyclists are attributed
solely to helmets, the laws in New Zealand still resulted in less than
a quarter of the injury reduction claimed in advance

Does this mean that the decline in cycling didn't completely account for
the drop in injury rates for cyclists?

[para 10]
According to the US Consumer Products Safety Commission, the risk of
head injury has approximately doubled during the period when helmet
use rose from under 20% to around 50%

Have cyclist KSIs continued to track those of other road users, but at a
lower relative level than they used to?

[para 11]
You mentioned one of the new pieces of research. Was the finding you
mentioned representative of the reports (cycle-relevent) findings? Are
there really no post-1997 studies that have 'pro-helmet' findings (i.e. was
this report cherry picked?)

[para 12]
why were the 2003 figures not used?
Were these a lot lower then? (I know, I know - stupid question :-). Wonder
how low the 2004 ones'll be..

[para 12]
The KSI figure for child cyclists in 2002 is about the same as that
for bus users - does the BMA think that bus travel is especially
dangerous?

I see your point, but it might be read as 'same as that for [child] bus
users' as IMO it isn't really a particularly valid comparison otherwise.

[para 13]
written by ?the? Lee and Mann

I suppose they could be that infamous to warrant a 'The'..

[Para 17]
brings the claimed benefit down to zero within the limits of statistical
accuracy.

Presumably the statistics aren't very accurate. What's the 95% range
thingy and is the zero you mention towards the end of this range?

[para 18]
a 19 per cent reduction in head injuries to cyclists in the three
years after the intoduction of legislation

You mention a careful selection of timeframe, but the study is the three
years after legislation! In what way was this a careful selection of
timeframe?

[Para 21]
much of the claimed reduction in head injuries turns out to have happened
before the programme started.

Out of pure interest, did they manage to claim the crdit for the reductions
that happened before the programme started? If so, how?

[para 25]
a poll of the BMA's own members placed helmets last in the hierarcgy
of possible effectiveness of various measures.

I can't believe that a load of normal doctors would be that sceptical of
the benefits of magic helmets! How representative was this poll of true
opinion amongst doctors?

I am not aware of any objective assessment of the relative merits of
various cycle safety interventions which puts helmets anywhere other
than last.

How many objective assessments are you aware of?

[para 27]
Lack of enforcement meant that helmet weearing rates did not change
after passage of the law

Did wearing rates really not change? Did rates rise sharply in the run up
to the law?

Thanks for the comments, gents - updated and stuck on the website for
want of a better use for it right now.

http://www.chapmancentral.co.uk/web/.../Documents/BMA


Guy
--
http://www.chapmancentral.co.uk

"To every complex problem there is a solution which is
simple, neat and wrong" - HL Mencken