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#21
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On Thu, 11 Nov 2004 16:09:14 GMT, "Steven M. Scharf"
wrote: And the people advocating it are in denial about the possibility that the likelihood of crashing in the first place will increase. I don't think that anyone is foolish enough to believe that helmet use will cause the likelihood of crashing to increase. Except the editor of Injury Prevention, one Barry Pless., who did a study to prove that risk compensation doesn't exist and found the exact opposite... How well-versed are you on risk compensation? Have you read Wilde? Adams? Are you aware of Hedlund's four tests for the likelihood of risk compensation? The people advocating the helmet laws aren't in denial of this possibility, or in acceptance of it; it's just so patently ridiculous that neither side has brought it up. You are displaying your ignorance again. There was an acrimonious exchange between the Thompsons and Rivara on one side, and John Adams and Mayer Hillman on the other, in Injury Prevention in June 2001, to name but one instance. 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 Washington University |
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#22
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On Thu, 11 Nov 2004 16:07:46 GMT, "Steven M. Scharf"
wrote: We know that the countries with the worst cyclist safety records have high helmet wearing rates. Your lack of logic is astounding. Oh do tell, what is the problem with the fact that the countries with the best cyclist safety record have the lowest helmet usage and those with the highest helmet usage have the worst safety record? Aside from the obvious: that it contradicts your cherished beliefs? I have spent two years as part of an international group studying helmet research. I have read more on this subject than I ever wanted to and the more I read the more uncertain the balance of evidence seems. I note that you have no answer to my main point, that there is no evidential basis for the current excessive focus on helmets. 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 Washington University |
#23
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Just zis Guy, you know? wrote:
On Thu, 11 Nov 2004 16:09:14 GMT, "Steven M. Scharf" wrote: And the people advocating it are in denial about the possibility that the likelihood of crashing in the first place will increase. I don't think that anyone is foolish enough to believe that helmet use will cause the likelihood of crashing to increase. Except the editor of Injury Prevention, one Barry Pless., who did a study to prove that risk compensation doesn't exist and found the exact opposite... Not to mention the fact that the passage of a law will transform the whole nature of society in ways that could be unpredictable. A butterfly flaps its wings in the Amazom and then a hurricane wipes out Florida, you know, that sort of thing! How well-versed are you on risk compensation? Have you read Wilde? Adams? Are you aware of Hedlund's four tests for the likelihood of risk compensation? I, for one, am unashamed to admit that I have no idea. But if you think these are good places to start, I'll look them up. The people advocating the helmet laws aren't in denial of this possibility, or in acceptance of it; it's just so patently ridiculous that neither side has brought it up. You are displaying your ignorance again. There was an acrimonious exchange between the Thompsons and Rivara on one side, and John Adams and Mayer Hillman on the other, in Injury Prevention in June 2001, to name but one instance. 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 Washington University I am not a lawyer. I do not even see email sent to this address, due to past DOS attacks. If you wish to respond, do so through this newsgroup. |
#24
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Just zis Guy, you know? wrote:
On Thu, 11 Nov 2004 16:09:14 GMT, "Steven M. Scharf" wrote: And the people advocating it are in denial about the possibility that the likelihood of crashing in the first place will increase. I don't think that anyone is foolish enough to believe that helmet use will cause the likelihood of crashing to increase. Except the editor of Injury Prevention, one Barry Pless., who did a study to prove that risk compensation doesn't exist and found the exact opposite... How well-versed are you on risk compensation? Have you read Wilde? Adams? Are you aware of Hedlund's four tests for the likelihood of risk compensation? The people advocating the helmet laws aren't in denial of this possibility, or in acceptance of it; it's just so patently ridiculous that neither side has brought it up. You are displaying your ignorance again. There was an acrimonious exchange between the Thompsons and Rivara on one side, and John Adams and Mayer Hillman on the other, in Injury Prevention in June 2001, to name but one instance. Steven seems to be a guy who tries to figure things out on his own. That's fine, of course, provided one has enough information. Steven's problem is he doesn't seem to go looking for information, unless he's trying to bolster his own beliefs! (We've seen this in the discussion about bicycle lights.) Risk compensation - that is, the tendency of people to behave more dangerously if they feel more protected - is widely accepted, and very easy to understand. In addition to Adam's book "Risk" (a very good source, btw) you can find a classic study on the web, "Target Risk" at http://pavlov.psyc.queensu.ca/target/index.html Chapter 7 discussed a study proving risk compensation in taxi drivers with anti-lock brakes. IOW, when the drivers knew they had those brakes, they took many more chances. Classic risk compensation. You can find other examples easily. And if you think about it, we get perfect evidence of risk compensation from time to time in these groups. When somone says "I won't ride around the block without a helmet" they're saying "I'm doing something I perceive as dangerous, and I'm doing it because I have protective gear. I'm willing to increase my risk because of the supposed protection." This can be fine, of course. There's no problem if the increase in risk matches the increase in protection. The problem with bike helmets is, they are promoted as being almost perfect protection ("85% effective!!!") but in reality, they are certified to protect only against a stationary topple off a bike - a "Laugh-In Fall." (Check out the certification standards online.) I recall being on a club mountain bike ride. Two of us were without helmets, about six others had helmets. At one spot, the group decided it would be fun to zoom down a very steep hill, launch up a rise at the bottom and "get big air." But the two of us decided that looked too dangerous. Within five minutes, we were walking our bikes back to our cars, helping the guy who'd broken his collar bone. Would he have broken that bone if he had no helmet? -- --------------------+ Frank Krygowski [To reply, remove rodent and vegetable dot com, replace with cc.ysu dot edu] |
#25
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On Thu, 11 Nov 2004 14:50:54 -0500, Frank Krygowski
wrote in message : Chapter 7 discussed a study proving risk compensation in taxi drivers with anti-lock brakes. IOW, when the drivers knew they had those brakes, they took many more chances. Classic risk compensation. You can find other examples easily. The irony here is that Scharf has actually cited ABS as an example where forecast injury savings were not realised in practice due to risk compensation, and drawn parallels with the case of helmets. Maybe the penny will drop eventually :-) 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 Washington University |
#26
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Just zis Guy, you know? wrote:
Oh do tell, what is the problem with the fact that the countries with the best cyclist safety record have the lowest helmet usage and those with the highest helmet usage have the worst safety record? Aside from the obvious: that it contradicts your cherished beliefs? What is wrong is trying to imply causation between high helmet usage and poor safety records (and vice-versa). This is the classic error of confusing correlation with causation. And BTW, I don't believe that you actually believe that there is causation, rather you're intentionally trying to mislead people who aren't skilled in critical thinking (and there are apparently a great many such people, judging from many of the posts in this thread). Did you know that eating ice-cream causes bicycle accidents? It’s a fact. The bicycle accident rate always goes up when ice cream sales go up. Yet we don’t regulate ice cream sales, but we force children to wear helmets, how terrible. Look at a country like the Netherlands and you'll understand why they have a better safety record, and it doesn't have anything to do with the percentage of people wearing helmets. But of course you already knew that. I've seen the argument raised that if there were no helmet laws then more people would cycle and facilities would improve, drivers would behave better, etc., but of course none of these wonderful developments occurred in the decades during which there were no helmet laws. I am not in favor of MHLs, they are too intrusive for the tiny reduction in injuries that is realized, and they do create the impression that bicycling is much more dangerous than it actually is. It is deplorable that Ontario is rushing this ill-advised bill into law, based on wild projections of hundreds of millions of dollars in savings due to reduced health care costs. OTOH, you are doing the anti-MHL cause no favor by descending to the same level of illogic as the proponents of these laws. For an amusing read, see: "http://www.thehammer.ca/content/view.php?news=2004-11-08-ontario-helmets-mandatory" |
#27
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On Fri, 12 Nov 2004 04:26:16 GMT, "Steven M. Scharf"
wrote: Oh do tell, what is the problem with the fact that the countries with the best cyclist safety record have the lowest helmet usage and those with the highest helmet usage have the worst safety record? Aside from the obvious: that it contradicts your cherished beliefs? What is wrong is trying to imply causation between high helmet usage and poor safety records (and vice-versa). Yes, it's every bit as wrong as trying to imply causation between helmet wearing and presentation in emergency rooms - both completely ignore the actual mechanisms of cause and effect in favour of pretending helmets make all the difference. But, unlike the authors of observational studies, I wasn't implying cause and effect. I was stating, as a matter of plain fact, that the countries with the best safety records have the lowest helmet usage rates. That is not to imply cause, but to raise the question: if helmets are, as the current monomaniac focus on them implies, the first, best thing for cyclist safety, how can this be? Look at a country like the Netherlands and you'll understand why they have a better safety record, and it doesn't have anything to do with the percentage of people wearing helmets. But of course you already knew that. The number one factor which increases cycle safety is more people cycling. Helmet promotion and compulsion are both proven to deter cycling. Ergo, helmet promotion is dangerous. I have yet to see any evaluation of the relative merits of different cycle safety interventions which puts helmets anywhere other than last. I've seen the argument raised that if there were no helmet laws then more people would cycle and facilities would improve, drivers would behave better, etc., but of course none of these wonderful developments occurred in the decades during which there were no helmet laws. What on earth are you on about? People were cycling for a century before helmets were ever invented, and in most countries where cycling is a normal mode of transport, helmet use is still negligible. Here is a little exercise for you. Plot on a graph the percentage of injuries which were head injuries for pedestrians and cyclists in New Zealand. Start five years before their mandatory helmet law, when helmet use was under 45%, and plot through to a couple of years after, when helmet use was over 95%. See if you can tell which line is which without looking at the legend. Now co-plot the helmet wearing rate. Correlate the helmet wearing rate with the relative %HI of cyclists and pedestrians. Ponder for a while what this tells us about the efficacy of helmets against recorded injuries and fatalities. Helmet promotion is justified with scare stories about death and serious injury. We know, because every single large scale study has told us so, that helmets make no measurable difference to death and serious injury rates. We also know that the risk of cycling is small to start with, and outweighed by the benefits. So the logical next step is for the handwringers to butt out and leave us alone. OTOH, you are doing the anti-MHL cause no favor by descending to the same level of illogic as the proponents of these laws. So you say. On the other hand, countering propaganda is usually seen as a Good Thing; I have already played a significant role in stopping one helmet law. 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 Washington University |
#28
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"Just zis Guy, you know?" wrote in message . ..
On Wed, 10 Nov 2004 03:26:26 GMT, "Steven M. Scharf" wrote: I can see both sides of the helmet issue. The pro-helmet people vastly SNIP A poll of British doctors put it sixth out of six possible interventions, a study by the Transport research Laboratory put it tenth of ten possible interventions and a factor of 25 behind the likely most effective, being traffic calming. Guy, Do you have a reference for the TRL study? I have not seen it and would like to read it. Guy John Kane KIngston, ON Canada |
#29
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On 12 Nov 2004 06:44:10 -0800, (JRKRideau)
wrote: Do you have a reference for the TRL study? I have not seen it and would like to read it. Yes and no: it passed through my hands about a week ago, but I don't have it to hand and I'll be away this weekend so I'll have to catch up with it later. Email me if I forget to follow up? 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 Washington University |
#30
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Just zis Guy, you know? wrote:
Yes, it's every bit as wrong as trying to imply causation between helmet wearing and presentation in emergency rooms - both completely ignore the actual mechanisms of cause and effect in favour of pretending helmets make all the difference. Not really. Your implication of causation is propaganda, pure and simple. You claim that you were just stating a fact, but the reality is that you want people to make a connection based on correlation, and many people do confuse correlation and causation. The emergency room statistics are valid in the context in which they are presented, in bicycle accidents involving impact to the head, helmeted cyclists fare far better in terms of the seriousness of injuries. The MHL proponents focus on this fact, ignoring the bigger picture. I have yet to see any evaluation of the relative merits of different cycle safety interventions which puts helmets anywhere other than last. This is not the point though. The MHL proponents will correctly point out that the other safety interventions cannot practically be implemented, or that even if they were, they should not be exclusive. You'll never win the debate based on the relative effectiveness of the different interventions. Here is a little exercise for you. Plot on a graph the percentage of injuries which were head injuries for pedestrians and cyclists in New Zealand. Start five years before their mandatory helmet law, when helmet use was under 45%, and plot through to a couple of years after, when helmet use was over 95%. See if you can tell which line is which without looking at the legend. Now co-plot the helmet wearing rate. Correlate the helmet wearing rate with the relative %HI of cyclists and pedestrians. Ponder for a while what this tells us about the efficacy of helmets against recorded injuries and fatalities. Again, you are confusing correlation with causation. You'll lose every time with that approach. Helmet promotion is justified with scare stories about death and serious injury. We know, because every single large scale study has told us so, that helmets make no measurable difference to death and serious injury rates. We also know that the risk of cycling is small to start with, and outweighed by the benefits. So the logical next step is for the handwringers to butt out and leave us alone. No argument there. But if you read the articles and letters in the Toronto newspaper, you'll see that this is barely mentioned. They are concentrating solely on the reduction in severity of injuries when accidents occur, not on the fact that the accidents are so rare as to be inconsequential. So you say. On the other hand, countering propaganda is usually seen as a Good Thing; I have already played a significant role in stopping one helmet law. Countering propoganda is a good thing when you do it with facts, rather than with more propoganda. Another good approach is to try to make the MHL proponents look ridiculous. I composed a letter to the Toronto Star, we'll see if it's published. It's along the lines of "Let's pass more laws to make everything safe for everyone." |
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