Invisible Cyclists in Solstice Dark

  • Thread starter Elisa Francesca Roselli
  • Start date



gds wrote:

> OK here we go back to implied character smear rather than arguing the
> issue. That is usually the tactic of folks who have no proof so need to
> displace the argument.


Whatever. Such character smears say a lot more about the smearer, than
the smearee.

> Let's be clear. No one, on either side of the debate, has been able to
> point to a prospective, population based study, designed with an "a
> priori" null hypothesis to test helmet efficacy. That would be the
> "gold standard" to be able to argue persuasively one way or the other.


Yes, if you want to look at efficacy over a population, what you say is
true. However if you simply want to look at how helmet wearers versus
non-helmet wearers fare in accidents, that data is readily available. Of
course there will be claims that such data is suspect because of risk
compensation, etc.

> The helmet sceptics keeping quoting the flaws of studies that show
> helmets to be efective and counter with citations, which when I review
> them all have serous methodological flaws. To everyone's credit no one
> disputs the existance of the flaws but some do seem to ignore the
> implication of the flaws and continue to quote the results.


This has been going on for as long as I can remember. As an engineer,
it's annoying to see the junk science on population studies, especially
since there are more than a few people that are taken in by it. These
junk science "studies" attempt to create "debaters' points" by looking
at two variables, without understanding (or understanding but ignoring)
the fact that there really is no correlation due to other variables that
they don't look at, or don't have data for.

> We should all understand that if a study has a serious flaw then the
> finidngs are suspect no matter how large the study.


It's more than that. A "study" is not counting the number of cyclists
that pass by a specific intersection, stating that the numbers are less
than they were a few years before the helmet law went into effect, and
then proclaiming that helmets cause vast number of people to stop
cycling. Yet such "studies" are routinely trotted out.
 
gds wrote in part:

> The helmet sceptics keeping quoting the flaws of studies that show
> helmets to be efective and counter with citations, which when I review
> them all have serous methodological flaws. To everyone's credit no one
> disputs the existance of the flaws but some do seem to ignore the
> implication of the flaws and continue to quote the results.


Bingo. Can't have it both ways fellas.

I would add that for some of the 'data' presented, no
methodology whatsoever is given. Anyone who
dares point this out is loudly proclaimed to be
impossible to please.

Robert
 
gds wrote:
> Richard wrote:
>
>>gds wrote:
>>
>>
>>>We should all understand that if a study has a serious flaw then the
>>>finidngs are suspect no matter how large the study.

>>
>>Not necessarily. Once the flaw is identified, the results can be
>>reinterpreted with the flaw in mind. Sometimes this may continue to
>>support the original findings; sometimes it may arrive at new findings;
>>sometimes it may mean that no conclusions may be drawn.
>>

>
>
> You are clutching at straws. Why can't you just admit that if you
> really want to know the answer you need to do a proper study.


The answer to what question, exactly? Is helmet wearing beneficial?
To the whole population? To non-helmet-wearers? (that isn't a facile
question) Is there any effect on the health of the population at large?
On the health of non-cyclists? (again, not facile). Is there any
effect on vehicle speeds, and hence pollution? Is helmet-wearing
beneficial to cyclists involved in crashes with vehicles? To cyclists
riding off-road? To child cyclists? Within what speed range? If it's
beneficial to a certain subset of cyclists and disbeneficial to
another subset of cyclists, would you say it's beneficial or
disbeneficial overall? If it decreases the chance of getting some
minor abraisions (a common injury after a fall) but increases the chance
of getting rotational head/neck injuries (not so common injury after a
fall) which are more likely to cause serious irreperable brain damage,
is it beneficial or disbeneficial? What range of numbers would you like
to qualify your answers?

The point is that there is no one "question", but many; and each
requires a separate methodology (and hence a separate study) to address.

And what exactly is a "proper" study, anyway?

> All this
> work to justify using bad data makes little sense to me.


It makes absolute sense to examine previous studies, their
methodologies, their flaws, their results, to see how to improve future
studies.

> Remember I'm not arguing for or agianst the question of helmet
> efficacy. I'm just wishing that someone studies it properly and shares
> the results.


Ah, again we have that word "properly".

R.
 
[email protected] wrote:

> If you're basing your whole anti-helmet-compulsion
> argument on an assumption that cycling is not dangerous,
> you're always going to have trouble getting over that
> hurdle. I would ditch it and move on, as it is not essential
> to the rest of the argument.


There are two valid anti-compulsion arguments. First is the personal
freedom issue. Second is the fact that statistically, the number of
injuries and fatalities that would be prevented by increasing helmet use
by compulsion, would be very small.

Countering the medical establishment's position on helmets is difficult
because they have much more respect by the public and the politicians
than people that rant about murder rates, walking helmets, gardening
accidents, etc. The key is to not try to use junk science to fight
helmet laws. Some people may be taken in by cute anecdotes, but those
aren't the people making the laws.
 
Richard wrote:
> gds wrote:
> > Richard wrote:
> >
> >>gds wrote:
> >>
> >>
> >>>We should all understand that if a study has a serious flaw then the
> >>>finidngs are suspect no matter how large the study.
> >>
> >>Not necessarily. Once the flaw is identified, the results can be
> >>reinterpreted with the flaw in mind. Sometimes this may continue to
> >>support the original findings; sometimes it may arrive at new findings;
> >>sometimes it may mean that no conclusions may be drawn.
> >>

> >
> >
> > You are clutching at straws. Why can't you just admit that if you
> > really want to know the answer you need to do a proper study.

>
> The answer to what question, exactly? Is helmet wearing beneficial?
> To the whole population? To non-helmet-wearers? (that isn't a facile
> question) Is there any effect on the health of the population at large?
> On the health of non-cyclists? (again, not facile). Is there any
> effect on vehicle speeds, and hence pollution? Is helmet-wearing
> beneficial to cyclists involved in crashes with vehicles? To cyclists
> riding off-road? To child cyclists? Within what speed range? If it's
> beneficial to a certain subset of cyclists and disbeneficial to
> another subset of cyclists, would you say it's beneficial or
> disbeneficial overall? If it decreases the chance of getting some
> minor abraisions (a common injury after a fall) but increases the chance
> of getting rotational head/neck injuries (not so common injury after a
> fall) which are more likely to cause serious irreperable brain damage,
> is it beneficial or disbeneficial? What range of numbers would you like
> to qualify your answers?
>
> The point is that there is no one "question", but many; and each
> requires a separate methodology (and hence a separate study) to address.
>
> And what exactly is a "proper" study, anyway?
>
> > All this
> > work to justify using bad data makes little sense to me.

>
> It makes absolute sense to examine previous studies, their
> methodologies, their flaws, their results, to see how to improve future
> studies.
>
> > Remember I'm not arguing for or agianst the question of helmet
> > efficacy. I'm just wishing that someone studies it properly and shares
> > the results.

>
> Ah, again we have that word "properly".
>


You are just answering with gibberish.

Of course, there are millions of questions. No single study will
address even a samll percentage of these. The discussion has clearly
been on the efficacy of helmets in preventing or mitigating injury.
Throwing in red herrings like the impact of helmets on pollution or the
effect of helmets on non cyclists is simply absurd.

And it is precisely that type of response which weakens any sort of
attempt to discuss this logically. If your rhetoric is an example of
how the folks who fight helmet laws argue the case then it is no wonder
that such laws pass. I am not particularly pro helmet but your
arguments make it appear as though the helmet sceptic ranks are
poulated by folks with no ability to make a reasoned argument.

Blather on!
 
[email protected] wrote:
> gds wrote in part:
>
>> The helmet sceptics keeping quoting the flaws of studies that show
>> helmets to be efective and counter with citations, which when I review
>> them all have serous methodological flaws. To everyone's credit no one
>> disputs the existance of the flaws but some do seem to ignore the
>> implication of the flaws and continue to quote the results.

>
> Bingo. Can't have it both ways fellas.
>
> I would add that for some of the 'data' presented, no
> methodology whatsoever is given. Anyone who
> dares point this out is loudly proclaimed to be
> impossible to please.


Yes, this is always amusing. Of course, if you look at some of the web
sites regarding helmets, you'll quickly understand that you don't need
any 'data' at all to make proclamations. Read "Helmet Disadvantages" at
"http://www.cycle-helmets.com/helmet_damage.html." Just use phrases like
"studies indicate," "have been known," etc., when you have no data! You
can convince people who believe everything they read, but of course
these people are just looking for reinforcement of what they already do.

The bottom line of the helmet wars is that the camps are arguing
different premises. The people arguing against helmets look solely at
population studies, but are hampered by the fact that proper studies do
not exist, so they always lose the debate whenever someone is audacious
enough to point out that their 'data' is really not data at all.

The people arguing in favor of helmets, though not necessarily helmet
compulsion, are looking at the tiny subset of cyclists that are involved
in injuries that are treated by paramedics, emergency rooms, and
hospitals, and are helped by the fact that such statistics are readily
available.

Unfortunately, the compulsion forces, usually driven by medical
organizations, have all the real data they need, while the
anti-compulsion forces have to argue from a personal freedom, and
relative risk perspective.
 
gds wrote:

> You are just answering with gibberish.
>
> Of course, there are millions of questions. No single study will
> address even a samll percentage of these. The discussion has clearly
> been on the efficacy of helmets in preventing or mitigating injury.
> Throwing in red herrings like the impact of helmets on pollution or the
> effect of helmets on non cyclists is simply absurd.
>
> And it is precisely that type of response which weakens any sort of
> attempt to discuss this logically. If your rhetoric is an example of
> how the folks who fight helmet laws argue the case then it is no wonder
> that such laws pass. I am not particularly pro helmet but your
> arguments make it appear as though the helmet sceptic ranks are
> poulated by folks with no ability to make a reasoned argument.


Well said. I am very anti-compulsion, I was very vocal against my
bicycle club adopting a compulsory helmet rule (and the anti-compulsion
forces were successful until our insurer insisted on compulsory
helmets). That said, the ride leaders that were against compulsion never
engaged in the sort of idiotic rhetoric that we have seen here. We
thought that individuals and ride leaders should decide if helmets were
required on a ride, but we acknowledged that it would be better to be
wearing a helmet in a crash than to not be wearing one.

If we had been ranting about side issues like walking or gardening
accidents, I have no doubt that the voting by the membership would have
come out very differently.
 
SMS wrote:
> These
> junk science "studies" attempt to create "debaters' points" by looking
> at two variables, without understanding (or understanding but ignoring)
> the fact that there really is no correlation due to other variables that
> they don't look at, or don't have data for.


Steven, at least _once_, could you give a proper, specific citation so
we know which study you're referring to?

At least once?

- Frank Krygowski
 
On Mon, 09 Jan 2006 10:48:06 -0800, SMS wrote:
> but we acknowledged that it would be better to be
> wearing a helmet in a crash than to not be wearing one.


Based on the same studies that have been mentioned ad nauseum or on
personal predudice?

Jon
 
[email protected] wrote:
> [email protected] wrote:
>
> > Robert's point has been that cycling is really, really dangerous.
> > Really. And if you have data that shows otherwise, it can't possibly
> > be correct, because cycling is really dangerous. Really.

>
> Crazy thing is, I've never seen much if any actual 'data'
> that shows otherwise.


Rather, you've not accepted the data that has been posted. Your most
insistent point has been that no "per hour" estimates are possible -
despite the fact that specialists in public safety have posted per-hour
estimates of risk of dozens of activities for decades.

> Most of what you post does not
> meet the bare minimum requirements to be considered
> useful data.


Again, that's your judgement, which is apparently influenced by your
prior notions.

> Now, I don't believe I've ever said anything like 'cycling is
> really, really dangerous.' Sorry. What I said, simply, was
> cycling in traffic is dangerous. Really.


True, that's what you've said. "Traffic" being defined as ...?? Does
"traffic" refer to Manhattan gridlock at 5 PM on Friday? Or is it
riding on a deserted country road when a Geo Metro passes you in the
opposite lane at 25 mph?

You may not recall (or choose to admit it), but in one post in 2005,
you actually answered that, saying "traffic" is when _any_ motor
vehicles are on the road. That really does reduce to "bicycling is
dangerous."

Really! ;-)

> The word dangerous, of course, does not have a set
> scientific definition, and will thus mean different things
> to different people.


And the only way to make sense of it, then, is to think of it
comparatively - that is, try to come up with some metric by which we
can compare the danger of bicycling to the danger of other common
activities. Especially ones that people do not fear.

Yes, there are different ways to compare - that is, depending on one's
point of view, one could look at fatalities, or major injuries, or all
(even minor) injuries; or any of the above per 100,000 population, or
per 100,000 participants, or per hour participation, or per mile
participation, or various combinations of the above.

My problem with your statements is this: Most of those metrics do,
indeed, say that cycling is no worse than activities people engage in
with no fear. But you tend to counter that fact by saying "We don't
really know those numbers." And you tend to focus on the minor
injuries that cyclists do get as "proof" that cycling is dangerous,
even though we _certainly_ don't know those numbers - because they're
minor, and nobody cares about minor injuries, so nobody collects that
data!

In summary, you have a strong tendency to reject that which makes
cycling sound good, and accept phantom, never-published data that you
believe makes cycling sound bad.

As if we need more fearmongering regarding cycling!

> If you're basing your whole anti-helmet-compulsion
> argument on an assumption that cycling is not dangerous...


I don't.

> ... you're always going to have trouble getting over that
> hurdle. I would ditch it and move on, as it is not essential
> to the rest of the argument.


Here, you're mimicking our friend Steven Scharf (aka SMS) who claims
that it's good to fight helmet compulsion, but that it must be done
using only the arguments of which he approves. Sorry, but neither you
nor he are in a position to judge.

And FWIW, my interest in promoting cycling greatly predates my position
in the helmet wars. When I first wrote
http://www.bicyclinglife.com/NewsAndViews/philosophy.htm I hadn't even
heard of any real data on helmets. In fact, at that time, I used to be
in favor of helmet promotion.

Since then, I've read and critiqued literally dozens of research papers
on the issue. They changed my attitude completely regarding helmets.
I no longer believe they have significant practical benefits.

But nothing has changed my belief that cycling is, indeed, a relatively
safe activity. Yes, even cycling "in traffic," whatever THAT means.

- Frank Krygowski
 
Jon Senior wrote:
> On Mon, 09 Jan 2006 10:48:06 -0800, SMS wrote:
>> but we acknowledged that it would be better to be
>> wearing a helmet in a crash than to not be wearing one.

>
> Based on the same studies that have been mentioned ad nauseum or on
> personal predudice?


Back then, no studies at all, it was all based on anecdotal evidence.
which is probably the reason that we were successful in preventing
compulsion.

If the same debate were attempted in the club today, absent the
insurance requirement, I don't think that the anti-compulsion forces
would have prevailed. You'd have the personal freedom advocates against
the people that would use the FARS data, which does show a benefit in
helmet use, and the FARS data is real, not made up. The pro-compulsion
forces would use the argument that if anyone wants to ride without a
helmet, they are perfectly free to do so, just not on a club ride.

Back in the 1980's, getting access to the actual data was not nearly as
simple as it is now, for better or for worse.

Note that no one in this thread is actually in favor of MHLs. Once you
dismiss the the studies with no methodology, it boils down to arguing
over which premise should be the basis of helmet effectiveness, the ER
studies which conclusively prove a benefit when accidents do occur, or
the fact accidents are not common enough to worry about helmets.
 
gds wrote:

> Well the flaw is that while what you claim is a reasonable hypothesis
> from the study it is not proven. It is not even addressed. It is simply
> a reasonable inference which should form the basis of further study to
> prove it (or not). That is what I am arguing--furhter study that
> actually addresses the question.


It is not even a reasonable inference, because it ignores so many other
variables. It's more of an unsupported hypothesis than a reasonable
inference. That particular paper, like many others, is superficially
impressive, but as you have pointed out, it is highly flawed.
 
On 9 Jan 2006 07:24:37 -0800, "gds" <[email protected]> said in
<[email protected]>:

>> You can't measure them.


>Yes you can! However it takes a proerly defined study to do so and not
>just a retrospective look at data. Please acquaint yoursel fwith
>population based epidemiological studies. There are whole sets of
>emthodologies to address just this type of issue.


No, you can't measure them. What value of accident? What value of
injury? What value of medical intervention? Do you want to know
about the time the shin got bashed while mounting?

Far too elastic.

Stick with something which is at least tolerably consistent: injuries
serious enough to require some kind of medical treatment. Because,
let's face it, those not serious enough to need treatment are not
serious enough to worry about are they?

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

"To every complex problem there is a solution which is
simple, neat and wrong" - HL Mencken
 
On 9 Jan 2006 08:02:47 -0800, [email protected] said in
<[email protected]>:

>What you're postulating is unlikely in the extreme - that at exactly
>the same time helmet use increases, that ridership increases. Would
>you pretend this happens in every jurisdiction, always perfectly
>synchronized? What are the odds of that?


Especially since, in every case where it has been measured accurately,
ridership actually decreased.

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

"To every complex problem there is a solution which is
simple, neat and wrong" - HL Mencken
 
On Mon, 09 Jan 2006 08:51:11 -0800, SMS <[email protected]>
said in <[email protected]>:

>The centerpiece of the junk science promulgated is to use causal
>arguments that are not justified by the data.


For an excellent example of this see the 1989 Seattle study, far and
away the most widely-cited helmet study (and also, coincidentally,
with far and away the highest estimate of efficacy).

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

"To every complex problem there is a solution which is
simple, neat and wrong" - HL Mencken
 
On 9 Jan 2006 09:13:42 -0800, "gds" <[email protected]> said in
<[email protected]>:

>OK here we go back to implied character smear rather than arguing the
>issue. That is usually the tactic of folks who have no proof so need to
>displace the argument.


Bollocks. Scharf is well-known: his number one technique is to
attribute to others those disparagements which best fit himself.

If you want to see junk science, read the pro-helmet studies. See how
researchers compare completely different groups of cyclists and
attribute more than 100% of the difference in injury rates to headgear
choice. Scharf has been told time and again that the correlation vs.
causation argument fallacy is most evident in the small-scale
observational studies which underpin helmet promotion. Whole issues
of the relevant journals have been given over to this kind of problem!
These small-scale studies are all vulnerable to that problem.

But Scharf chooses to accept them uncritically (fault 1), assume that
all time-series studies do the same (fault 2), reverses the burden of
proof (fault 3) and then accuses the sceptics of being zealots (fault
4). In every case his criticisms are *far* more relevant to the
obsessive-compulsives than to those of us who read and try to
understand the mass of conflicting evidence.

The worst possible fault is the Scharf's starting point: to assume
that *anything* in this area is sufficiently black-and-white as to
permit any sentence containing words like "always".

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

"To every complex problem there is a solution which is
simple, neat and wrong" - HL Mencken
 
On 9 Jan 2006 09:13:42 -0800, "gds" <[email protected]> said in
<[email protected]>:

>The helmet sceptics keeping quoting the flaws of studies that show
>helmets to be efective and counter with citations, which when I review
>them all have serous methodological flaws. To everyone's credit no one
>disputs the existance of the flaws but some do seem to ignore the
>implication of the flaws and continue to quote the results.


And? All that is necessary is to show that those proposing the
intervention, do so on the basis of badly flawed methodology (which is
unquestionably true, as anyone who has read these papers in detail
will know).

Compulsion and scepticism are not opposites. Scepticism is the
default position. I co9uld just as easily say that you must wear a
St. Christopher medal, and then pick holes in any study you produce to
show the converse.

It's really incredibly simple: if you predict a value of efficacy for
helmets, you should be able to prove it from reductions in %HI in real
populations which have experienced large changes in helmet usage rates
over a short time. Observational studies are all vulnerable to
confounding, so should be treated with scepticism until supported by
other evidence. In the case of helmets there is *no* other evidence
supporting helmet use. Every other study methodology, good or bad,has
come up with a zero rate of efficacy. The largest (Rodgers) covered
eight million cyclist injuries and found a small but not significant
rise in head injury rates and a small but significant rise in fatality
rates for helmeted cyclists. But all this is an aside, because in the
end all we, the sceptics, have to do is stand here and say "Prove it!"

They can't.

All they do is produce another observational study, vulnerable to
exactly the same confounding.

Don't you think it's right that those who propose the intervention
should have to prove their case to the sceptical public, rather than
the other way around?

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

"To every complex problem there is a solution which is
simple, neat and wrong" - HL Mencken
 
On 9 Jan 2006 11:45:25 -0800, "gds" <[email protected]> said in
<[email protected]>:

> "Results revealed that the increased helmet wearing percentages has
>had little association with serious head injuries to cyclists as a
>percentage of all serious injuries to cyclists for all three
>groups,..."


>The study was not population based and therefor has no data to indicate
>what was going on in the general population. It was a look at accidents
>it was not a look at what was happening overall.


So? You introduce something claimed to prevent 85% of head injuries,
you track %HI for cyclists and pedestrians, you force a large
proportion of the cyclists to start using the device claimed to
prevent 85% of head injuries, it is reasonable to expect a change in
%HI in cyclists. But there was none.

So, the ball passes back to those proposing the intervention: "Prove
it!" You wouldn't want to reverse the burden of proof, would you?

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

"To every complex problem there is a solution which is
simple, neat and wrong" - HL Mencken
 
On 7 Jan 2006 23:02:42 -0800, [email protected] said in
<[email protected]>:

>Actually any survey ever done that compares
>driving and cycling in terms of injuries shows
>cycling to be much more dangerous than driving,
>in terms of injuries, in the US, AFAIK.


Apart from the ones that don't, such as those Frank has posted. But
of course they run counter to your macho bike messenger "living on the
edge" world-view, so are dismissed out of hand.

All of which fails to explain why cyclists insist on living longer
than average, when cycling is so self-evidently dangerous...

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

"To every complex problem there is a solution which is
simple, neat and wrong" - HL Mencken
 
gds wrote:
>
> You are clutching at straws. Why can't you just admit that if you
> really want to know the answer you need to do a proper study. All
> this work to justify using bad data makes little sense to me.
> Remember I'm not arguing for or agianst the question of helmet
> efficacy. I'm just wishing that someone studies it properly and
> shares the results.
>


The longitudinal studies you want are very unlikely to be carried out
but the time series measurements are mostly quite competent and
perfectly valid whereas the case control/observational studies have been
widely criticised not only in helmets but in many other areas of health
where they have produced a number of seriously wrong and misleading
results.

Try reading:
Classics in epidemiology; should they get it right? Smith GD.
International Journal of Epidemiology 2004;33:441-2.
Hormone replacement therapy and coronary heart disease: four lessons.
Pettiti D. Int Jour Epid 2004;33:461-3.

The first says:
"It is, at the very least, clear that observational epidemiology may be
more fallible than some have suggested".

"An important clue as to whether the findings of individual-level
associations in observational epidemiological studies are likely to
be causal can come from time-trend or ecological data."


The second says

Do not turn a blind eye to contradictory evidence (such as from
whole population time-series data) and especially do not repudiate
it, but try instead to understand the reasons behind the
contradictions.

--
Tony

"The best way I know of to win an argument is to start by being in the
right."
- Lord Hailsham