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#1271
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On Sat, 29 Jan 2005 18:03:42 GMT, "Steven M. Scharf"
wrote in message t: It is logical to conclude that the overwhelmingly higher number of deaths for non-helmeted cyclists is why the serious injury numbers for the non-helmeted cyclists are not higher than they are. You say. On the other hand we know from a large volume of data especially from Australia and New Zealand that the head injury and fatality rate does not change with helmet use - and in fact the percentage of helmeted head injured cyclists in Australia is currently exactly the same as the percentage of helmeted cyclists overall. So either you are wrong, or you are relying only on tiny observational studies with their well-documented sampling bias. I would remind you that the British Government could not find an example where cyclist safety had improved with increasing helmet use. 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 |
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#1272
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On Sun, 30 Jan 2005 02:08:06 -0500, "Riley Geary"
wrote in message : [snip analysis] Small data sets is always an issue. I recall that Rodgers analysed similar data for every cycle crash in the USA over 15 years - about eight million incidents - and found (a) no evidence that helmet use was correlated with significantly reduced head injury rates; (b) a significantly higher fatality rate among helmeted cyclists and (c) a far greater benefit in reductions in injuries from the introduction of standards for manufacture and sale of bicycles. For some reason everybody seems to think a couple of hundred injured cyclists in Seattle gives a more accurate picture than 8,000,000 crashes across the whole USA ;-) 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 |
#1274
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On Thu, 27 Jan 2005 02:29:42 GMT, (Bill Z.)
wrote in message : As I said, due to *budget problems* a desirable program got scaled back. I bet the helmet promotion didn't. Mainly because it's paid for by SafeKids, funded by Bell. Nonsense - it got scaled back by having city employees handle it and taking out some or all of the on-road classes. It still covers accident avoidance. You really are determined to miss the point, aren't you? So, who is running the WHO Cycle Training Imitative? Who is pressing for mandatory cycle training laws? How many schools forbid children to cycle to school unless they have passed Effective Cycling? How many general cycle safety posters do you see posted in schools and youth clubs? I am a school governor, and all cycling matters at the school pass in front of me. In the last year we've had six sets of helmet promotion literature and not one promoting general cycle safety. A woman is coming to the Spring Fair to train children on how to wear helmets; there will be no maintenance or skills training provided. And yet every evaluation I have seen of the merits of various cycle safety measures puts helmets last. 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 |
#1275
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Guy wrote:
Small data sets is always an issue. I recall that Rodgers analysed similar data for every cycle crash in the USA over 15 years - about eight million incidents... How could anyone possibly do that. I think what you mean is that he analysed available data from ER visits? - and found (a) no evidence that helmet use was correlated with significantly reduced head injury rates; (b) a significantly higher fatality rate among helmeted cyclists and (c) a far greater benefit in reductions in injuries from the introduction of standards for manufacture and sale of bicycles. For some reason everybody seems to think a couple of hundred injured cyclists in Seattle gives a more accurate picture than 8,000,000 crashes across the whole USA ;-) Regarding the "fatality rate" in (b), please clarify what kind of fatality rate. Fatalities-per-hour, fatalities-per-injury, fatalities-per-accident, fatalities-per-participant, or what. This is a crucial distinction. Robert |
#1276
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wrote in message ups.com... Riley Geary wrote in part: wrote in message ups.com ... What does the 1200-to-1 ratio of injuries-to- fatalities mean? This number shows us that cycling is highly unlikely to cause your death, but that it causes a ****load of injuries. This is the dualism that some appear unable to grasp. True, but keep in mind that the overwhelming majority of bicycling injuries are relatively minor or even trivial in nature, and that most of these actually occur to juvenile cyclists as part of the sometimes painful process of growing up and experiencing the real world. Yes, but remember also that 1200-to-1 is the ratio of those seeking medical attention for their injuries to fatalities, not the ratio of ALL injuries to fatalities. If you define "seeking medical attention" as showing up at an ER, the CDC data would suggest the ratio with respect to fatalities is more like 600 or 700-to-1. In my personal experience and observation, cyclists tend to hurt themselves far more often than they visit the ER or seek outpatient treatment. The number of ALL injuries is unknown and unknowable, but a 5,000-to-1 ratio of total injuries-to-fatalities seems reasonable. The ratio of hospitalizations to fatalities would be what? About 60-to-1? No, more like 25-to-1. The ratio of hospitalizations to fatalities for motor vehicle occupants is only about 6-to-1, and just 4-to-1 for pedestrians. OTOH, the ratio for non-traffic-related bicycle hospitalizations to fatalities is probably close to 50-to-1. Keep in mind this simply demonstrates that even among the more serious injuries requiring hospitalization, cyclists are much less likely to die from their injuries than either motor vehicle occupants or pedestrians (this is generally considered a good thing, though I suppose it may depend on your perspective). Using CDC data from http://webappa.cdc.gov/sasweb/ncipc/nfirates2001.html to put matters in some perspective, less than 1 out of every 26 trips to the ER by a bicyclist results in hospitalization, compared to nearly 1 out of every 16 trips by a motor vehicle occupant, about 1 out of every 8 trips by a motorcyclist, ... Speed kills. But just being on two wheels is problematic for many folks. The numerical bulk of cycling injuries comes from solo wipeouts-- resulting in generally mild to moderate injuries. Very few serious injuries or deaths, but a ton of minor to moderate injuries. While the towering pile of collarbones is impressive, what SHOULD grab our attention in this discussion--trust me on this--is the range of potential injury faced by the cyclist in traffic. Which, not surprisingly, is similar to the range of injury faced by drivers and pedestrians in traffic, and NOT similar to the range of injury faced by basketball players or couch sitters. Very true, but then couch sitters tend to suffer from a whole range of serious health risks later in life due to their sedentary lifestyle; and even for traffic-related injuries, cyclists suffer far fewer fatalities relative to either serious injuries (~1 per 22 hospitalizations) or all injuries for which medical attention is sought (~1 per 400 trips to the ER) compared to either motor vehicle occupants (~1 per 85 ER visits) or pedestrians (~1 per 28 ER visits). It's important to remember also that cyclists in the ER may be less likely to be hospitalized than drivers in the ER, cyclists are more likely to end up there in the first place, on a per-mile or per-hour basis. Granted, even though a disproportionate number of those ER visits are due to juvenile cyclists, and thus have little real relevance to adult cycling conditions. It's also important to remember that a "minor injury" in the grand scheme of injuries may not seem so minor to someone who is dealing with it. If you rip your calf open on your chainring, for instance, and have to go in for 30 stitches, that's a minor injury. When I ripped my finger to the bone, in the NEISS data it would read something like LACR PINKY, which would surely get Frank a-snickerin' ("skinned knees"), but if he had been on the scene he might have lost his lunch. It's good policy to withhold judgment on somebody else's "minor injuries" until you've had a few yourself. But minor injuries are not really what I'm talking about here. ... nearly 1 out of every 7 trips by a pedestrian, Of traffic-related pedestrian accidents. But "pedestrian accidents" (unintentional falls while walking) are by far the number one cause of ER visits across all age groups. Pedestrians in the ER are hospitalized far less often than cyclists. Not according to the CDC data--unless you're including non-transportation-related falls around the home, etc. Total ER trips by pedestrians (as defined by the CDC, both traffic-related and non-traffic-related) are only about 1/3 the number of bicycle-related ER trips (~175k vs ~500k/year), even though pedestrians account for slightly more total hospitalizations than bicyclists (~24k vs ~19k/year), and roughly 8 times as many fatalities (~6000 vs ~750/year). But then, that is the sort of ratio relationship we would expect where one type of activity tends to produce a much larger fraction of serious to fatal injuries compared to some other activity. Riley Geary |
#1277
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Just zis Guy wrote:
On Thu, 27 Jan 2005 10:25:44 -0800, Benjamin Lewis wrote in message : I'm at a loss why anyone should care that if you cycle more, you're at a greater yearly risk of sustaining a cycling related injury. Not only is this completely obvious, it's not interesting or useful for anything. Obvious? You think? Risk per what? per mile? Yearly risk is what I said. I'd be amazed if that was not substantially lower for a high-mileage cyclist. Ditto per hour. Per year? It would depend on how many miles of low risk-per-mile cycling the high mileage cyclist does compared to the low-mileage cyclist and their higher risk-per-mile cycling. Last time I checked there was no binary split between high and low mileage cyclists, so it would depend very much on where exactly you draw the line between low and high mileage. I'm still reasonable certain that if you plotted yearly risk against yearly mileage for the "average cyclist", the graph would be monotonically increasing, although with a slope of less than one. I agree that the hourly or per mile risk would go down. -- Benjamin Lewis Tip the world over on its side and everything loose will land in Los Angeles. -- Frank Lloyd Wright |
#1278
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Riley Geary wrote:
A more serious problem is that you're looking at just a single year's worth of data, and due to the relatively small number of fatalities involved, it may or may not be an accurate representation of the broader picture. As it turns out, the HSMV website you've referenced currently contains 10 years worth of data (1994-2003), and 1997 just happens to have the lowest I didn't choose 1997, while I was searching, that was the PDF that came up in the search results, I didn't know there were other years data available. OTOH, I recently spent a week in Florida at Daytona Beach, and of the 50+ cyclists I observed there, just 1 was wearing a helmet, so I suppose it's at least possible that the Florida helmet use data is a fair reflection of reality. I am from Florida, and was just back there earlier this month. Helmet use is pretty low. Most of the cycling appears to be in beach towns, and on college campuses, not a lot of commuting at all (too hot). So I do think that Florida's low level of helmet use may be an anomaly. Frankly, the 1.4 figure does seem a lot more reasonable than the 3.4 figure, since 21-33% more fatalities for non-helmeted riders is what we've seen in other parts of the world. There will never be a double-blind study, and the data will always be subject to the influence of rider skill level, sobriety, age, etc., and the real possibility that a helmet wearer is more likely to be someone who follows traffic laws, uses lights at night, and exercises reasonable caution. |
#1279
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Riley Geary wrote:
If you define "seeking medical attention" as showing up at an ER, the CDC data would suggest the ratio with respect to fatalities is more like 600 or 700-to-1. "Seeking medical attention" means just that. The NEISS estimates a half million outpatients seeking treatment for a bicycle-related injury in addition to the half million ER visits. The number of ALL injuries is unknown and unknowable, but a 5,000-to-1 ratio of total injuries-to-fatalities seems reasonable. The ratio of hospitalizations to fatalities would be what? About 60-to-1? No, more like 25-to-1. The ratio of hospitalizations to fatalities for motor vehicle occupants is only about 6-to-1, and just 4-to-1 for pedestrians. OTOH, the ratio for non-traffic-related bicycle hospitalizations to fatalities is probably close to 50-to-1. Keep in mind this simply demonstrates that even among the more serious injuries requiring hospitalization, cyclists are much less likely to die from their injuries than either motor vehicle occupants or pedestrians (this is generally considered a good thing, though I suppose it may depend on your perspective). I want to be clear here. Are you saying that motor vehicle occupants are hospitalized at 4 times the rate of cyclists who have been injured in a car-bike accident? Or of cyclists who have been injured in all types of bicycle accidents? Big difference obviously. It seems that the rate of hospitalization would be similar for all parties involved in an accident with a motor vehicle, whether the injured party be on a bike, on foot, or a passenger in a car. That is my suspicion anyway. ...but then couch sitters tend to suffer from a whole range of serious health risks later in life due to their sedentary lifestyle; Yes of course. But everybody sits on the couch, even avid cyclists. When we do so, we are at much less risk of accidental injury than when we are riding our bikes. and even for traffic-related injuries, cyclists suffer far fewer fatalities relative to either serious injuries (~1 per 22 hospitalizations) or all injuries for which medical attention is sought (~1 per 400 trips to the ER) compared to either motor vehicle occupants (~1 per 85 ER visits) or pedestrians (~1 per 28 ER visits). "Traffic-related injuries?" So all those would involve contact with a motor vehicle then? Otherwise it seems like you are just giving another stat that shows that cyclists face a greater likelihood of minor injury compared to their driving counterparts (due to solo wipeouts), IN ADDITION to facing a similar risk with regard to motor-vehicle involved accidents. Granted, even though a disproportionate number of those ER visits are due to juvenile cyclists, and thus have little real relevance to adult cycling conditions. Very true, although I suspect this is true even if the kids' injuries are culled out. A disproportionate number of the "trivial" ER visits belong to kids as well. Adults don't go to the ER for "skinned knees." But "pedestrian accidents" (unintentional falls while walking) are by far the number one cause of ER visits across all age groups. Pedestrians in the ER are hospitalized far less often than cyclists. Not according to the CDC data--unless you're including non-transportation-related falls around the home, etc. Well, yeah, we include non-transportation- related cycling injuries don't we? Or do we simply classify ALL cycling accidents as "traffic-related?" If you look at the CDC data (which I linked to from your site--great resource, thanks), you see that unintentional falls while walking around (in the park, across the street, in the home, whatever) are the number one cause of injury across all age groups. Total ER trips by pedestrians (as defined by the CDC, both traffic-related and non-traffic-related) are only about 1/3 the number of bicycle-related ER trips (~175k vs ~500k/year), even though pedestrians account for slightly more total hospitalizations than bicyclists (~24k vs ~19k/year), and roughly 8 times as many fatalities (~6000 vs ~750/year). But then, that is the sort of ratio relationship we would expect where one type of activity tends to produce a much larger fraction of serious to fatal injuries compared to some other activity. Well, you have to define "pedestrian" very narrowly to get that ratio. Robert |
#1280
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"Just zis Guy, you know?" writes:
On Thu, 27 Jan 2005 02:15:20 GMT, (Bill Z.) wrote in message : Err, Benjamin, the discussion is about helmets and biases you get in statistics regarding the comparison of different groups of cyclists. On which subject I recommend the 1989 Seattle study, a very good example of these biases in action. You recommend that one? Good for you. -- My real name backwards: nemuaZ lliB |
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