Cycling UK Forum

A little more research:

A case-control study of the effectiveness of bicycle safety helmets

Thompson RS, Rivara, Thompson DC. The New England Journal of Medicine Vol 320:21 pp1361-7, 1989.

A study conducted at five hospitals in Seattle between December 1986 and December 1987 of cyclists admitted to an emergency room. Of 776 cyclists admitted, 269 had head injuries. 235 of these, and 433 of the 507 cyclists who were admitted without head injuries, completed a questionnaire. The study concluded that cycle helmets reduce the risk of head injury by 85% and of brain injury by 88%. [j264]

Also:

Helmet protection from head injuries among recreational bicyclists *

Wasserman et al. American Journal of Sports Medicine Vol 18:1 pp 96-7, 1990.

Predicts helmets would reduce concussions by 29%, skull fractures by 82%.


Also:


Evaluation of the bicycle helmet law in Victoria during its first four years

Carr, Skalova, Cameron. Monash University Accident Research Centre Report 76, 1995.
Abstract available on-line

Together with Evaluation of the bicycle helmet wearing law in Victoria during its first 12 months, Head injury reductions in Victoria two years after introduction of mandatory bicycle helmet use, and Bicyclist head injuries in Victoria three years after the introduction of mandatry helmet use, comprises a year-on-year evaluation of head injuries following the introduction of the Victoria helmet law.

Hospital data did not show relationship between helmet wearing and head injury in immediate pre-law years for crashes not involving a motor vehicle. However, head injury rates for cyclists in these crashes were significantly lower post-law. A significant inverse relationship between helmet use and head injury was found for cyclists involved in crashes with motor vehicles. Accident claims showed head injury rates significantly below pre-law predictions in second post-law year, but benefit appeared to have been lost in third year. Hospital records failed to show any additional benefit of law over pre-law trends in the 3 post-law years.

1995 report found biases in injury data used in previous reports, affecting analysis and results, and suggested that hospital admissions for head injury in first 4 years was 40% below pre-law trends and that severity of injuries had declined.

Report abstracts make no reference to trends in the number of people cycling or relative risk.


Shall I continue?

david143 wrote:I think the problem I have with a few anti-helmet posters here is that they will take anything said and turn it so they can argue their right not to wear a helmet.

i feel my right to choose not to have one is under threat.
do you feel your choice to have one is under threat?

so we're all pro choice? i'd be happy if we could all just leave it at that

hubgearfreak wrote:

david143 wrote:I think the problem I have with a few anti-helmet posters here is that they will take anything said and turn it so they can argue their right not to wear a helmet.

i feel my right to choose not to have one is under threat.
do you feel your choice to have one is under threat?

so we're all pro choice? i'd be happy if we could all just leave it at that

I never got close to even hint of a threat, and still got jumped on.

I feel my right to choose is compromised by the lies and false claims made on both sides.

The argument for and against has become so fixed, I do believe it will take Government intervention to end it.

All we get is claims and counter claims, reports and counter reports, lies and more lies, and nobody wins except those that are happy with the fight for the fights sake.

Not quite true David. Most of us are wise enough to discern fact from fiction. Therefore, if a cyclist weighs up all the pro's and cons and then decides to wear a helmet,he (or she) wins because they feel they've made the right choice and will probably be more confident on the road. (So long as it's not a false sense of confidence. But then, that'a a risk we all take from time to time).

The other winner is ofcourse the helmet maker. And that's one of the reasons I don't want it to ever become compulsory.

For those of you interested in the BMJ article, here is a link:

http://www.bmj.com/cgi/content/full/321/7268/1055

This shows a marked decrease in head injuries during the period of the study, quite at odds with what an earlier poster claims.

I regard cyclists as a community of people who share a common interest, and if by posting some links to real papers (ie BMJ and NEJM), not hearsay, I can make one person re-consider their position on not wearing a helmet then I feel I will have done my bit.

As always, the choice is the individuals, but as a mathematician, I cannot let statistics be used to distort the 'facts' as percieved by some. If, after looking at the evidence an individual chooses to ignore it, then so be it, just do so from a position where the risks are quantified.

Dave

in the old days...

when bicycles were first being used...

were helmets about then??

No, and no brakes either, and when cars were first used they didn't have seatbelts....

Or airbags, crumple zones, SIPS or any of the other safety measures.

Dave

so no brakes...

was it like a single speed / track bike set up...???

Ever seen a track rider without a helmet?

Can't see what that has to do with day-to-day riding and helmet use though.

Dave

pioneer wrote:Not quite true David. Most of us are wise enough to discern fact from fiction.

Being wise is not the issue. Facts and figures can and have been used to tell most lies. It is how you use them and how some are left out to give the picture required.

Both sides do it, so you get to the point where neither side can be trusted to tell the truth or not manipulate data collected in some way.

dbrunner wrote:No, and no brakes either, and when cars were first used they didn't have seatbelts....

Or airbags, crumple zones, SIPS or any of the other safety measures.

Dave

Cars used to have a man running in front of it with a red flag.

hubgearfreak wrote:so we're all pro choice? i'd be happy if we could all just leave it at that

but sadly, we don't seem to be able to do so

Well I don't know about you David, But I can tell what's tosh and what's not.

What you've just described about manipulating data could in fact be any one of a number of govt' departments. Beleive that lot at your peril!

If I think my bonce will be safer ensconced in a helmet I'll wear one. And no amount of diatribe from side or the other will make any difference.

However, personal stories from cycling freinds involved in accidents would make a difference. Helmet wearers or otherwise. That would probably be my benchmark for judgement.

dbrunner wrote:A little more research:

A case-control study of the effectiveness of bicycle


Evaluation of the bicycle helmet law in Victoria during its first four years

Carr, Skalova, Cameron. Monash University Accident Research Centre Report 76, 1995.
Abstract available on-line

Together with Evaluation of the bicycle helmet wearing law in Victoria during its first 12 months, Head injury reductions in Victoria two years after introduction of mandatory bicycle helmet use, and Bicyclist head injuries in Victoria three years after the introduction of mandatry helmet use, comprises a year-on-year evaluation of head injuries following the introduction of the Victoria helmet law.

Hospital data did not show relationship between helmet wearing and head injury in immediate pre-law years for crashes not involving a motor vehicle. However, head injury rates for cyclists in these crashes were significantly lower post-law. A significant inverse relationship between helmet use and head injury was found for cyclists involved in crashes with motor vehicles. Accident claims showed head injury rates significantly below pre-law predictions in second post-law year, but benefit appeared to have been lost in third year. Hospital records failed to show any additional benefit of law over pre-law trends in the 3 post-law years.

1995 report found biases in injury data used in previous reports, affecting analysis and results, and suggested that hospital admissions for head injury in first 4 years was 40% below pre-law trends and that severity of injuries had declined.

Report abstracts make no reference to trends in the number of people cycling or relative risk.


Shall I continue?

Yes please...........


These works are flawed by methodology.

The easiest one to explain is the Victoria research.

Helmet legislation was part of a raft of other legislation including a wide clampdown on drink driving, dangerous driving, speeding and vehicle standards and safety. There is no allowance made for any of these factors - any or all of which could be a contributory factor in the reduction of accidents.

To ignore these factor is naive and to contribute the decrease in injuries to helmet use only a deeply flawed assumption.


The fact that there is no allowance or the reduction in the number of cyclists a point you graciously pointed out is the biggest single flaw in the research

If all cycle accidents is examined, the number of non head injuries falls at the same rate.

If helmet use was the cause of this decrease the number of head injuries should have fallen at a faster rate than non head injuries. The similar rate of decrease suggests that it was the decrease in the number of cyclists and in general road safety.

Now I know there are some weird claims about helmets, but are we supposed to believe they were also miraculously preventing limb and abdominal injuries!

The unfortunate fact is that by limiting the case study to head injuries only the results are numerically true, but the conclusion is neither accurate nor correct.


Shall I continue?

dbrunner wrote:Ever seen a track rider without a helmet?

Dave

There were several on our local track on Sunday, all thoroughly enjoying themselves up and down the bankings.

All of them went home alive, too.