Ozonation

I wasn't going to respond much more to this thread, but since you ask, sure... here you go. Happy trails.

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Trauma Acute Care Surg. 2013 Nov;75(5):877-81. doi: 10.1097/TA.0b013e3182a85f97.
Helmet use is associated with safer bicycling behaviors and reduced hospital resource use following injury.

Webman R, Dultz LA, Simon RJ, Todd SR, Slaughter D, Jacko S, Bholat O, Wall S, Wilson C, Levine DA, Roe M, Pachter HL, Frangos SG.
Source

From the Departments of Surgery (R.W., L.A.D., R.J.S., S.R.T., D.S., S.J., O.B., C.W., H.L.P., S.G.F.), Emergency Medicine (S.W., D.A.L.), and Pediatrics (D.A.L.), Bellevue Hospital Center, New York University School of Medicine; and Office of Research, Implementation and Safety (M.R.), NYC Department of Transportation, New York, New York.

From the Departments of Surgery (R.W., L.A.D., R.J.S., S.R.T., D.S., S.J., O.B., C.W., H.L.P., S.G.F.), Emergency Medicine (S.W., D.A.L.), and Pediatrics (D.A.L.), Bellevue Hospital Center, New York University School of Medicine; and Office of Research, Implementation and Safety (M.R.), NYC Department of Transportation, New York, New York.
Abstract

BACKGROUND:

While the efficacy of helmet use in the prevention of head injury is well described, helmet use as it relates to bicyclists' behaviors and hospital resource use following injury is less defined. The objective of this study was to compare the demographics, behaviors, hospital workups, and outcomes of bicyclists based on helmet use.
METHODS:

This study was a subset analysis of a 2.5-year prospective cohort study of vulnerable roadway users conducted at Bellevue Hospital Center, a New York City Level 1 trauma center. All bicyclists with known helmet status were included. Demographics, insurance type, traffic law compliance, alcohol use, Glasgow Coma Scale (GCS) score, initial imaging studies, Abbreviated Injury Scale (AIS) score, Injury Severity Score (ISS), admission status, length of stay, disposition, and mortality were assessed. Information was obtained primarily from patients; witnesses and first responders provided additional information.
RESULTS:

Of 374 patients, 113 (30.2%) were wearing helmets. White bicyclists were more likely to wear helmets; black bicyclists were less likely (p = 0.037). Patients with private insurance were more likely to wear helmets, those with Medicaid or no insurance were less likely (p = 0.027). Helmeted bicyclists were more likely to ride with the flow of traffic (97.2%) and within bike lanes (83.7%) (p < 0.001 and p = 0.013, respectively). Nonhelmeted bicyclists were more likely to ride against traffic flow (p = 0.003). There were no statistically significant differences in mean GCS score, AIS score, and mean ISS for helmeted versus nonhelmeted bicyclists. Nonhelmeted patients were more likely to have head computed tomographic scans (p = 0.049) and to be admitted (p = 0.030).


CONCLUSION:

Helmet use is an indicator of safe riding practices, although most injured bicyclists do not wear them. In this study, helmet use was associated with lower likelihood of head CTs and admission, leading to less hospital resource use. Injured riders failing to wear helmets should be targeted for educational programs.

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Accid Anal Prev. 2013 Oct;59:206-12. doi: 10.1016/j.aap.2013.05.027. Epub 2013 Jun 4.

Trends in head injuries associated with mandatory bicycle helmet legislation targeting children and adolescents.

Karkhaneh M, Rowe BH, Saunders LD, Voaklander DC, Hagel BE.
Source

Semnan University of Medical Sciences, Department of Social Medicine, Iran.

Abstract

BACKGROUND:

Bicycling related head injuries (HIs) can be severe. Helmet use reduces head injury risk; however, there are few controlled studies of the effect of helmet legislation. We conducted this study to investigate changes in HIs after bicycle helmet legislation targeting those <18 in Alberta, Canada in 2002.

METHODS:

Bicyclist and pedestrian (control) HI rates and HIs as a proportion of all injuries were compared for the three years (1999-2001) before and four years (2003-2006) after bicycle helmet legislation in three age groups (children: <13, adolescents: 13-17, and adults: 18+).
RESULTS:

There were 41,270 ED visits and 2782 hospitalizations for bicyclists and 9836 ED visits and 2029 hospitalizations for pedestrians (excluding the legislation year 2002). The rate of ED HIs declined for child bicyclists and child pedestrians, while the rate of non-HIs declined in adult bicyclists and child pedestrians. The rate of hospitalized HIs declined in child bicyclists and all ages of pedestrians while non-HI rates declined for child and adult pedestrians. Non-HI rates for adolescent and adult bicyclists increased. After adjusting for sex and location, the proportion of ED bicycle HIs declined by 9% (APR=0.91; 95% CI: 0.86, 0.95) in children, was unchanged among adolescents and increased in adults (APR=1.08; 95% CI: 1.01, 1.15). The proportion of bicycle HI related hospitalizations decreased by 30% (APR=0.70; 95% CI: 0.55, 0.90) in children, 36% (APR=0.64; 95% CI: 0.49, 0.84) in adolescents and 24% (APR=0.76; 95% CI: 0.63, 0.91) in adults. There were no observed changes in the proportion of pedestrian HIs resulting in ED visits or hospitalizations.
INTERPRETATION:

Our data indicate significant declines in the proportion of child bicyclist ED HIs and child, adolescent and adult bicyclist HI hospitalizations. This is in contrast to no significant trends in the proportion of ED or hospitalized HIs among pedestrians and the unexpected increases in the proportion of ED HIs for adult bicyclists. Comparing bicyclist and pedestrian trends in the proportion of child and adolescent HIs suggests a bicycle helmet legislation effect.

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J Pediatr. 2013 Sep;163(3):726-9. doi: 10.1016/j.jpeds.2013.03.073. Epub 2013 May 24.

Bicycle helmet laws are associated with a lower fatality rate from bicycle-motor vehicle collisions.

Meehan WP 3rd, Lee LK, Fischer CM, Mannix RC.
Source

Micheli Center for Sports Injury Prevention, Waltham, MA, USA. concussion.sportsmed@childrens.harvard.edu

Abstract

OBJECTIVE:

To assess the association between bicycle helmet legislation and bicycle-related deaths sustained by children involved in bicycle-motor vehicle collisions.
STUDY DESIGN:

We conducted a cross-sectional study of all bicyclists aged 0-16 years included in the Fatality Analysis Reporting System who died between January 1999 and December 2010. We compared fatality rates in age-specific state populations between states with helmet laws and those without helmet laws. We used a clustered Poisson multivariate regression model to adjust for factors previously associated with rates of motor vehicle fatalities: elderly driver licensure laws, legal blood alcohol limit (<0.08% vs ≥ 0.08%), and household income.
RESULTS:

A total of 1612 bicycle-related fatalities sustained by children aged <16 years were evaluated. There were no statistically significant differences in median household income, the proportion of states with elderly licensure laws, or the proportion of states with a blood alcohol limit of >0.08% between states with helmet laws and those without helmet laws. The mean unadjusted fatality rate was lower in states with helmet laws (2.0/1,000,000 vs 2.5/1,000,000; P = .03). After adjusting for potential confounding factors, lower fatality rates persisted in states with mandatory helmet laws (adjusted incidence rate ratio, 0.84; 95% CI, 0.70-0.98).

CONCLUSION:

Bicycle helmet safety laws are associated with a lower incidence of fatalities in child cyclists involved in bicycle-motor vehicle collisions.

===========================
Traffic Inj Prev. 2013;14(5):501-8. doi: 10.1080/15389588.2012.727217.

Bicycle helmets: head impact dynamics in helmeted and unhelmeted oblique impact tests.

McIntosh AS, Lai A, Schilter E.
Source

Transport and Road Safety Research, Faculty of Science, The University of New South Wales, Sydney, Australia. as.mcintosh@bigpond.com

Abstract

OBJECTIVE:

To assess the factors, including helmet use, that contribute to head linear and angular acceleration in bicycle crash simulation tests.
METHOD:

A series of laboratory tests was undertaken using an oblique impact rig. The impact rig included a drop assembly with a Hybrid III head and neck. The head struck a horizontally moving striker plate. Head linear and angular acceleration and striker plate force were measured. The Head Injury Criterion was derived. The following test parameters were varied: drop height to a maximum of 1.5 m, horizontal speed to a maximum of 25 km/h, helmet/no helmet, impact orientation/location, and restraint adjustment. Additional radial impacts were conducted on the same helmet models for comparison purposes. Descriptive statistics were derived and multiple regression was applied to examine the role of each parameter.
RESULTS:

Helmet use was the most significant factor in reducing the magnitude of all outcome variables. Linear acceleration and the Head Injury Criterion were influenced by the drop height, whereas angular acceleration tended to be influenced by the horizontal speed and impact orientation/location. The restraint adjustment influenced the outcome variables, with lower coefficients of variation observed with the tight restraint.
CONCLUSIONS:

The study reinforces the benefits of wearing a bicycle helmet in a crash. The study also demonstrates that helmets do not increase angular head acceleration. The study assists in establishing the need for an agreed-upon international oblique helmet test as well as the boundary conditions for oblique helmet testing.

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Accid Anal Prev. 2013 Apr;53:78-88. doi: 10.1016/j.aap.2013.01.005. Epub 2013 Jan 16.
The effectiveness of helmets in bicycle collisions with motor vehicles: a case-control study.

Bambach MR, Mitchell RJ, Grzebieta RH, Olivier J.

Source

Transport and Road Safety Research, University of New South Wales, Australia. m.bambach@unsw.edu.au

Abstract

There has been an ongoing debate in Australia and internationally regarding the effectiveness of bicycle helmets in preventing head injury. This study aims to examine the effectiveness of bicycle helmets in preventing head injury amongst cyclists in crashes involving motor vehicles, and to assess the impact of 'risky cycling behaviour' among helmeted and unhelmeted cyclists. This analysis involved a retrospective, case-control study using linked police-reported road crash, hospital admission and mortality data in New South Wales (NSW), Australia during 2001-2009. The study population was cyclist casualties who were involved in a collision with a motor vehicle. Cases were those that sustained a head injury and were admitted to hospital. Controls were those admitted to hospital who did not sustain a head injury, or those not admitted to hospital. Standard multiple variable logistic regression modelling was conducted, with multinomial outcomes of injury severity. There were 6745 cyclist collisions with motor vehicles where helmet use was known. Helmet use was associated with reduced risk of head injury in bicycle collisions with motor vehicles of up to 74%, and the more severe the injury considered, the greater the reduction. This was also found to be true for particular head injuries such as skull fractures, intracranial injury and open head wounds. Around one half of children and adolescents less than 19 years were not wearing a helmet, an issue that needs to be addressed in light of the demonstrated effectiveness of helmets. Non-helmeted cyclists were more likely to display risky riding behaviour, however, were less likely to cycle in risky areas; the net result of which was that they were more likely to be involved in more severe crashes.

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Accid Anal Prev. 2013 Nov;60:15-23. doi: 10.1016/j.aap.2013.07.011. Epub 2013 Aug 6.

A computational simulation study of the influence of helmet wearing on head injury risk in adult cyclists.

McNally DS, Whitehead S.
Source

Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, UK. Electronic address: donal.mcnally@nottingham.ac.uk.

Abstract

Evidence for the effectiveness of cycle helmets has relied either on simplified experiments or complex statistical analysis of patient cohorts or populations. This study directly assesses the effectiveness of cycle helmets over a range of accident scenarios, from basic loss of control to vehicle impact, using computational modelling. Simulations were performed using dynamics modelling software (MADYMO) and models of a 50% Hybrid III dummy, a hybrid cross bicycle and a car. Loss of control was simulated by a sudden turn of the handlebars and striking a curb, side and rear-on impacts by a car were also simulated. Simulations were run over a representative range of cycle speeds (2.0-14.0ms(-1)) and vehicle speeds (4.5-17.9ms(-1)). Bicycle helmets were found to be effective in reducing the severity of head injuries sustained in common accidents. They reduced the risk of an AIS>3 injury, in cases with head impacts, by an average of 40%. In accidents that would cause up to moderate (AIS=2) injuries to a non-helmeted rider, helmets eliminated the risk of injury. Helmets were also found to be effective in preventing fatal head injuries in some instances. The effectiveness of helmets was demonstrated over the entire range of cycle speeds studied, up to and including 14ms(-1). There was no evidence that helmet wearing increased the risk of neck injury, indeed helmets were found to be protective of neck injuries in many cases. Similarly, helmets were found to offer an increase in protection even when an increase in cycle speed due to risk compensation was taken into consideration.

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CMAJ November 20, 2012 vol. 184 no. 17 First published October 15, 2012, doi: 10.1503/cmaj.120988

• © 2013 Canadian Medical Association or its licensors
• All editorial matter in CMAJ represents the opinions of the authors and not necessarily those of the Canadian Medical Association.

• Research

Nonuse of bicycle helmets and risk of fatal head injury: a proportional mortality, case–control study

• Navindra Persaud, MD MSc⇓,
  
• Emily Coleman, BA,
• Dorothy Zwolakowski, BA,
• Bert Lauwers, MD,
  
• Dan Cass, MD

+ Author Affiliations

• From the Office of the Chief Coroner for Ontario (Persaud, Coleman, Zwolakowski, Lauwers, Cass), Toronto, Ont.; Keenan Research Centre, (Persaud) Li Ka Shing Knowledge Institute, St. Michael’s Hospital; the Department of Family and Community Medicine, St. Michael’s Hospital, University of Toronto, Toronto, Ont.; the Department of Family and Community (Lauwers), Medicine of McMaster University, Hamilton, Ont.; and the Division of Emergency Medicine (Cass), the University of Toronto, Toronto, Ont.
• Correspondence to:
  Navindra Persaud, nav.persaud@utoronto.ca

Abstract

Background: The effectiveness of helmets at preventing cycling fatalities, a leading cause of death among young adults worldwide, is controversial, and safety regulations for cycling vary by jurisdiction. We sought to determine whether nonuse of helmets is associated with an increased risk of fatal head injury.

Methods: We used a case–control design involving 129 fatalities using data from a coroner’s review of cycling deaths in Ontario, Canada, between 2006 and 2010. We defined cases as cyclists who died as a result of head injuries; we defined controls as cyclists who died as a result of other injuries. The exposure variable was nonuse of a bicycle helmet.

Results: Not wearing a helmet while cycling was associated with an increased risk of dying as a result of sustaining a head injury (adjusted odds ratio [OR] 3.1, 95% confidence interval [CI] 1.3–7.3). We saw the same relationship when we excluded people younger than 18 years from the analysis (adjusted OR 3.5, 95% CI 1.4–8.5) and when we used a more stringent case definition (i.e., only a head injury with no other substantial injuries; adjusted OR 3.6, 95% CI 1.2–10.2).

Interpretation: Not wearing a helmet while cycling is associated with an increased risk of sustaining a fatal head injury. Policy changes and educational programs that increase the use of helmets while cycling may prevent deaths.

rydabent

ozonation

Aw-----------come on man--------------the anti helmet crowd hate facts, it makes them look bad.

mconlonx

Thanks for this.

Goodness, bare-headers, there's a lot of cherished arguments being put to the test here. I especially like the one about oblique impacts since that one seems to send bare-headers into a tizzy, considering axonal rotation forces are a leading cause of concussion...

Brian Ratliff

I think that settles it then. It does for me. That and the poll above the thread showing a 84%/16% helmet/non-helmet ratio. Whatever the arguments, seems people have it settled in their own mind. It appears that data agrees as well.

I've hit my head a few times in races. This argument has been settled for me quite a long time ago. Helmets mitigate head injury. Helmet laws probably decrease cycling participation slightly, but I'll bet that this effect is temporary - people who want to bike aren't going to suddenly stop biking just because someone mandates a $20 helmet be worn. The helmet law might oust some soft participants from the cycling population (people who could take it or leave it when it comes to cycling), and it might cause a couple people to temporarily quit out of protest, but I can't see how people who bike for the right reasons will be affected by a helmet law. As can be seen in the poll, most people these days expect helmets to be part of cycling.

Spreading risk via insurance is the mechanism whereas freedom of choice is to be questioned. Even our new healthcare law with no pre-existing conditions has explicit penalties on smokers. One might make the case (though the data probably isn't strong enough yet), that if you make the choice to not wear a helmet while cycling, you should not spread that risk to others in the insurance pool.

noisebeam

When my mom bought my brothers and I helmets in the early 80s we immediately decided their best use was sprinting toward each other and trying to knock the other guy off bike using our heads - a type of jousting. We ended up destroying the helmets and my mom gave up and didn't buy more.

Brian Ratliff

I would dare say this says more about you and your brother than it does about helmets...

Besides, real men would use sticks and go for the eyes.

FBinNY 

So, following that logic, how about risky sexual behavior, reckless diet/obesity, drinking, participation in risky sports, perhaps including cycling itself?

If we accept the premise that the societal impacts of our actions justifies regulation, we essentially sacrifice the very basis on which free society is founded. Any minority engaging in an activity that the "enlightened" majority feels is raising social costs is at risk. There is no place to draw the line because once it's drawn it sets the basis for the next line.

I don't dispute that helmets can mitigate head injury, but I dispute that the difference is as great as some would have us believe. I also do not believe that bicycling is inherently dangerous enough to call for a helmet (when compared to everyday risks around us).

What I see among helmet advocates is a mental feedback loop, whereby having already decided that helmet use makes sense for them, cannot fathom why others cannot see the light, and feel obligated to protect the unenlightened form their own ignorance. This puts (some of) them in the same category as reformed smokers, or drinkers who often become the most vocal prohibitionists.

For those who believe that the risky behavior of others raises their cost of living and feel justified in correcting that, consider that you may have habits that others may feel warrant regulation.

I know I'll get flamed for using the following quote because of the context, but it's apropos to my point..

First they came for the communists,
and I didn't speak out because I wasn't a Communist.

Then they came for the Socialists
and I didn't speak out because I wasn't a Socialist.

Then they came for the trade unionists,
and I didn't speak out because I wasn't a trade unionist.

Then they came for me,
and there was no one left to speak for me.
Martin Niemöller



At some point you have to decide whether you want to live in a well ordered and regulated society, or whether you believe in the pursuit of happiness, and accept, or better yet cherish the differences in how each of choose to pursue it.

I respect the decision of anyone who chooses to wear a helmet, and no justification is needed. All I ask is that you respect my decision not to on the same terms.

noisebeam

We used the trunks of small trees. I was the older brother of twins and did what was needed to survive.

Brian Ratliff

Private insurance used to do this in spades to generate profit. It is no longer legal in the medical insurance market in the US. I am simply stating how the argument "let people do what they want" will have to address the topic of shared risk through medical insurance. If, god forbid, you bit it on the streets and aren't wearing a helmet for ideological reasons and are forced to the ER, will you pledge to pay for your ER visit using cash?

Rightfully so. Nobody is out to get you. The only question is of shared costs leading to shared responsibility for risk. If you aren't in my insurance pool, you can do what you want. If you are, then I do have some interest in your lifestyle choices because my insurance premium carries the burdens of your medical treatments. The law dictates how much of my interest is warranted to take into account - it is not allowed to this point. But that doesn't mean I can't put peer pressure on you in response to this shared cost responsibility.

Again, nobody is challenging your happiness etc. It is merely a matter of cost burden. If you are going to take well established risks (I've made clear that helmets don't yet fall in this category and law is explicit in this point), then others sharing your cost burden have a vested interest in your lifestyle choices.

If you are off the grid, I don't give a s**t what you do to yourself. Personally, I would respect your choice to not wear a helmet more if you subsequently pledge to keep your insurance card in your pocket if you, at some point, end up in the ER for an unhelmeted head injury after a bike crash. Money talks, if you are truly about individuality etc.

I-Like-To-Bike

Where do you get such strange notions from? Do you take your own arguments seriously?

Brian Ratliff

Not usually. But I noticed you didn't address the argument at all. Is there a problem with my logic? Insurance spreads costs over many people; it stands to reason that those people have an interest in each member's lifestyle. How do you reconcile this with the rhetoric of the rugged individualist?

LesterOfPuppets

Falling in the bath and falling on stairs are common TBI causes.
Safety helmets should be hung near such hazards so that we can save on insurance.

LesterOfPuppets

Do also advocate for helmets for non-racing automobile operators?

FBinNY 

Such sanctimonious drivel. For the record, private health insurance an many (most?) states had no lifestyle/risk litmus tests, and were specifically prohibited from having any. It's only people like you who would introduce them, once who gets and who pays for health care is determined through the political process.

If you read your own words, it's clear that you have no sense of principle, except that you don't want to pay for others any more than they pay for you. For your own sake, I hope you don't have any preferences or habits that others may feel adds to their burden.

BTW- just for the record, until federal regulation under the health care bill declared my policy illegal, I was willing to pay for my own care. I carried a very high deductible umbrella health care policy for catastrophic care, and paid the rest out of pocket.

mconlonx

This is the crux of the matter.

Forget ludicrous arguments saying people who wear helmets while riding a bike are hypocrites if they are not wearing a helmet in the shower, on a ladder, or just walking along. Cars are a much better example -- auto accidents are first or second in cause of head injury.

Instead of going after cyclists for not wearing helmets because they will be a drag on public costs, let's deal with the much greater social cost of head injury as a result of auto accidents. Before there should be any thought of mandatory helmet use laws for cyclists, every motorist should be required to wear one.

Brian Ratliff

non sequitur

We are talking about cyclists, not automobiles. And they already have any number of safety requirements that minimize risk to the operator and other road users.

LesterOfPuppets

We're now talking about things affecting your health insurance cost. If you were really interested in reducing your insurance rates you'd call for an outright ban on the automobile for personal use.

Brian Ratliff

This is most definitely NOT the crux of the matter. Ehrm. Sorry, let me start again. To say this is the "crux of the matter" is ludicrous and sanctimonious drivel and shows you have no sense of principle. Sorry. I forgot my allotment of over-the-top adjectives.

Just because one risk category is not address means we cannot address a different risk category? Please, support your point that helmet wearing while cycling has anything at all to do with driving a car. If you think car safety regulations are insufficient (remember, there are already a lot of them, just not helmets), then there is no reason for not addressing these two separate issues concurrently.

*Did you just suggest that "...cars are a much better example" of a ludicrous argument? I agree, but I'm not really sure how this meshes with the rest of your post.

LesterOfPuppets

Yes, let's consider different risk categories.

Let's compare helmet usage in short track speed skating vs. skating around Rockefeller Center.
Now compare those to usage in crits and riding a 3-speed to work.

Should EVERY bike ride really necessitate helmet usage. Seems over-reaching to me. Personal Protection Equipment levels should be just that - PERSONAL.

Brian Ratliff

No, actually we are talking about shared costs associated with bicycle helmet use, specifically. I'm fine with my insurance costs.

This is in counter to arguments of the "live and let live" genre which argue that everyone is an individual shiny snowflake and they should make their own decisions on these matters. I am merely suggesting that their decision affects others around them. If there really is very little risk of ending up in an ER because of hitting an unhelmeted head on the ground, maybe these people making these arguments simply pledge not to subject the others in their insurance pool to their costs.

All I know is I walked away from a 30+mph highside crash onto a banked velodrome (pulling about 1.5Gs) with my helmeted head. I walked away more or less okay. Others have died from similar crashes. Not saying the helmet "saved my life" as others so sanctimoniously state, but it definitely mitigated the effects of the collision.

Brian Ratliff

Nope. We are talking about bicycling helmets for bicycling. Not other risk categories. Don't change the subject.

Brian Ratliff

I thought we were past word games, what, with 6000 odd posts to this thread. Or is this shifting to a "bumper sticker slogan" thread?

I can do it too: PLEASE wear a helmet. THINK of your children.

LesterOfPuppets

Racing anecdotes should probably belong in a different realm altogether.

If you think bicycling helmets should be worn for all bicycle rides then surely there are MANY other activities that would warrant helmet use.

Seems over-reaching to me. YMMV

LesterOfPuppets

Sorry, no children.

I'll wear a helmet when I want to, thank you very much.

When you wear a helmet for EVERY automobile trip you take I'll consider donning one for every bicycle trip I take.

Brian Ratliff

Not the argument. The argument is in counter to those who claim that "Personal Protection Equipment should be just that - PERSONAL". No, PPE is protective equipment people WEAR on their person. Most of time where that moniker is used, that equipment is actually mandated by law. The mandate is to protect OTHERS from shared liabilities.