On Fri, 04 Feb 2005 02:41:52 GMT,
[email protected] (Bill Z.)
wrote in message <
[email protected]>:
>> >Funny that your side's only argument seems to be to rant about this
>> >single paper, as you pretty much ignore anything else.
>> Nice try, Bill, but seriously at odds with the facts.
>Try again - your side's argument is *not* a series of URLs you post
>now, but what the argument that is being posted by your side of the
>discussion *on this newsgroup.* Furthermore, what you *rant* about
>are the studies you are *complaining* about.
My "side"'s argument is that the evidence is far from clear,and that
the burden of proof remains solidly with those proposing intervention,
not with those urging scepticism. That evidence which purports to be
clear - such as the 1989 Seattle study, which remains the single most
widely-quoted study in the world despite its widely-publicised flaws -
turns out to be flawed. Discussing these flaws is necessary when
people quote the studies. It's called debating the evidence, and it's
the way science and public policy should always work.
Naturally the word "rant" is not pejorative, since the man who throws
a hissy-fit whenever he is called on to produce evidence would never
dream of being rude, since that would be rank hypocrisy.
>As I said, you people rant about T&R's paper as if that is the *only*
>paper that ever reported a postive result regarding helmets.
The UK's primary helmet promoters have just revised their website, and
85% is quoted as the figure for efficacy. This despite the fact that
they were judged to be unable to support it in a recent complaint to
the UK's advertising standards body. So they clearly think the 1989
Seattle study - the largest efficacy figure from any study I can think
of - is the best to quote. The fact that it is well-known to be bogus
clearly does not matter to them. Or to the local authorities whose
websites parrot the figure, often supplied to them by these people.
No other study since has managed to duplicate the figure, which is
hardly a surprise because few other authors would be foolish enough to
compare entirely different groups of cyclists and attribute all the
difference in injury rates to helmets rather than behavioural
differences. Like it or not, the bogus 1989 study is the single most
influential piece of helmet research in the world.
Going back a way I used to believe that stuff as well. Then the
faults in the Seattle study were drawn to my attention, and I read it,
and found that it is extraordinarily poor. And I started reading
other helmet studies and found that they, too, are often extremely
poor. So when they are quoted uncritically I (and others who have
read them) tend to speak up. And it turns out that very few of the
people quoting these figures have actually read and understood the
studies, and fewer still have considered the conflicting evidence.
Many of them are unaware that conflicting evidence even exists.
>If you do a google search on this newsgroup, you'll find that the people
>who consistently bring up this 85% figure are all charter members of
>the anti-helmet crew.
Really? There are people here who are anti-helmet? Who would they
be?
85% figure quoted as fact without caveat:
http://www.childalert.co.uk/absolutenm/PPL.TB/whydontchildrenw-1-9.asp
http://www.ich.ucl.ac.uk/gosh_families/ask_dr_jane_collins/body/cycle_helmets.htm
http://www.edd.gov.je/site.asp?NavID=405&SubID=2&PageID=571
http://www.headway.org.uk/default.asp?step=4&pid=157
http://www.essexcc.gov.uk/vip8/ecc/ECCWebsite/display/guideContents/index.jsp?oid=16298
http://www.cornwall.gov.uk/Environment/Safety/education/cycle.htm
http://www.cwu.org/default.asp?Step=4&pid=177
http://www.dorsetcc.gov.uk/index.jsp?articleid=169841
http://www.peterborough.gov.uk/news/pressreleases/2001-08/20010808001.shtml
http://www3.cambridgeshire.gov.uk/transport/around/cycling/safer_cycling.htm
http://www.capt.org.uk/pdfs/CSWquizhelmets.pdf
http://www.projectboxes.co.uk/resources/smash/cycle_helmets.doc
http://www.dhs.ca.gov/ps/cdic/epic/bike/default.htm
http://www.texmed.org/has/prs/hhh/default.asp
http://www.bhit.org
And of course:
http://www.helmets.org/stats.htm
Randy Swart says that he is aware of the fact that 85% is wrong but
that the figure is so ingrained in the injury prevention community
that "a change would not be helpful" - i.e. don't confuse them with
facts.
In fact it's quote hard to find any site recommending helmets which
does not use the claim "up to 85%" or even the plain figure 85% injury
reduction without even admitting that it is the absolute upper end of
estimates.
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