Searching for statistics and studies

For all discussions about this "lively" subject. All topics that are substantially about helmet usage will be moved here.
User avatar
Wanlock Dod
Posts: 566
Joined: 28 Sep 2016, 5:48pm

Re: Searching for statistics and studies

Postby Wanlock Dod » 28 Sep 2017, 9:20am

In an attempt to summarise and refocus, some people believe that it might be interesting at least to know what proportion of dead cyclists were wearing helmets.
AdamS wrote:...Specifically, does anyone know if data about the proportion of fatalities/ serious head injuries sustained by helmeted cyclists has ever been published for the UK?...

And it would appear that the basic information may be available
mjr wrote:...Helmet-wearing or not is in the casualty variables in police collision reports (STATS19, described by STATS20 2011 Annex 3 section 3.20) but it doesn't appear to be published in the Reported Road Casualties of GB data. You might be able to request it under Freedom of Information, or at least some summary of it...

I don't think it's the kind of thing that anybody is ever going to profit from, people will always have bigger priorities even if there is somebody badgering them to consider it, so waiting for somebody else to do it probably isn't a very productive strategy.
Whilst I tend to think that it might be a worthwhile cause, I can also well imagine that it would be a considerable effort, and that to build a database which also contains enough additional information would only increase the difficulty.

I often feel that the kinds of studies that tend to summarise helmet efficacy (such as those just posted by Steady rider) seem not to include many fatal incidents, yet helmets are considered to be required because they "could save your life." Getting to the point that the kinds of injuries that helmets are preventing are not tending to be fatal ones might be helpful in some way, although I dare say it's all been said before.

Ultimately, we need to bear in mind that most people will read the excellent summary from the BMJ which tells them that even if they do wear a helmet it is unlikely to offer any kind of observable benefit, then choose to wear one because "it can't do any harm can it."

User avatar
meic
Posts: 19355
Joined: 1 Feb 2007, 9:37pm
Location: Caerfyrddin (Carmarthen)

Re: Searching for statistics and studies

Postby meic » 28 Sep 2017, 9:32am

Ultimately, we need to bear in mind that most people will read the excellent summary from the BMJ which tells them that even if they do wear a helmet it is unlikely to offer any kind of observable benefit, then choose to wear one because "it can't do any harm can it."

The number of people who have a problem with that are almost infinitely few.
It is when that somehow develops to "so I will force everybody to wear one" or even just the kids, that it becomes a problem.
Yma o Hyd

Steady rider
Posts: 2261
Joined: 4 Jan 2009, 4:31pm

Re: Searching for statistics and studies

Postby Steady rider » 28 Sep 2017, 9:49am

Selling or promoting any product and not disclosing that it may have negative side effects is questionable. Some researcher try to cover up the true effects of legislation. All part of the history of the cycle helmet story.

User avatar
mjr
Posts: 16223
Joined: 20 Jun 2011, 7:06pm
Location: Norfolk or Somerset, mostly
Contact:

Re: Searching for statistics and studies

Postby mjr » 28 Sep 2017, 11:55am

meic wrote:The number of people who have a problem with that are almost infinitely few.

Like one of my teachers used to say, correctness isn't a popularity contest!

If helmets do cause more crashes, whether through enlarging and weighting the head or through something else like impaired decision-making because you've wrapped your brain in insulating foam with holes that cause cold draughts when moving faster, then it really ought to be explored and explained. It's irresponsible to recommend a treatment that seems ineffective and hasn't been tested rigorously.
MJR, mostly pedalling 3-speed roadsters. KL+West Norfolk BUG incl social easy rides http://www.klwnbug.co.uk
All the above is CC-By-SA and no other implied copyright license to Cycle magazine.

User avatar
pjclinch
Posts: 4021
Joined: 29 Oct 2007, 2:32pm
Location: Dundee, Scotland
Contact:

Re: Searching for statistics and studies

Postby pjclinch » 28 Sep 2017, 12:52pm

Wanlock Dod wrote:Ultimately, we need to bear in mind that most people will read the excellent summary from the BMJ which tells them that even if they do wear a helmet it is unlikely to offer any kind of observable benefit, then choose to wear one because "it can't do any harm can it."


Gill's Cycling and Children and Young People has an interesting postscript:

This author’s personal view is that helmet wearing is a sensible measure for adults and children. I will continue to wear a helmet, and will continue to tell (and eventually, to ask) my daughter to do the same, partly to reduce the damage and distress caused by the comparatively minor mishaps that are most likely to befall cyclists, and partly (if I am honest) because of the power of the ‘what if…’ question, were anything more serious to befall her or me. But those of us who cycle should be under no illusion that helmets offer reliable protection in crash situations where our lives may be in danger. Neither should we believe that widespread adoption of helmet wearing would see many fewer cyclists killed or permanently disabled. The evidence so far suggests otherwise.


This is a report that concludes that the case hasn't been made to either recommend or require helmets.

My take is that what is entirely reasonable as a personal decision and what is entirely reasonable as a policy decision can be two very different things. A lot of the problem with the helmet "debate" is that too many people think they are/should be the same thing. Public policy should be robustly evidence based and it should be logically consistent with other similar policies. Personal policy can be based on anything you want and needs no consistency.

Pete.
Often seen riding a bike around Dundee...

User avatar
Wanlock Dod
Posts: 566
Joined: 28 Sep 2016, 5:48pm

Re: Searching for statistics and studies

Postby Wanlock Dod » 28 Sep 2017, 1:23pm

Wanlock Dod wrote:...then choose to wear one because "it can't do any harm can it."

I feel it's appropriate to clarify what I mean by this, although I appreciate it is a bit of a diversion. I believe that peoples views about the risks posed by various activities are informed by a variety of indicators, many of which are most likely unreliable in terms of indicating overall risk. As more cyclists wear helmets more people (both cyclists and non-cyclists) begin to view cycling as a relatively dangerous activity. This seems to be evidenced by the widely held belief that cycling is more dangerous than walking, which is why most people choose to wear a helmet whilst cycling but not whilst walking. Some non-cyclists view cycling as far too dangerous an activity for them to get involved in, but are more than happy to walk instead. This is arguably depressing the numbers of cyclists on the roads with an result in terms of danger to cyclists through the safety in numbers effect.
Cyclists which wear helmets might risk compensate and end up riding less safely (but perhaps to a similar level of perceived overall risk), I know that I do this when I wear a helmet. Most cyclists that I know wear helmets and record their rides, but choose not to investigate the effects that helmets might have on their riding. Motorists might also feel that helmeted cyclists are protected, so need less care on the road. Some of the most enthusiastic helmet promoters I've ever come across are motorists apparently acting out of concern for cyclists.
Overall I am of the view that there are a variety of ways in which "innocent" helmet use can have negative effects on safety for cyclists as a population, yet can only possibly be of any benefit on an individual level. I know that my choice not to wear a helmet has challenged peoples views about how dangerous cycling really is, and I remain optimistic that over time it will result in improved conditions not just for me but for all cyclists in the area, through an increase in numbers cycling.

User avatar
bovlomov
Posts: 4202
Joined: 5 Apr 2007, 7:45am
Contact:

Re: Searching for statistics and studies

Postby bovlomov » 28 Sep 2017, 1:24pm

pjclinch wrote:Public policy should be robustly evidence based and it should be logically consistent with other similar policies. Personal policy can be based on anything you want and needs no consistency.

I've always thought that the helmet debate was different from most others, in its total separation from reason. But how much public policy is robustly evidence based? Not education (an area where there's a lot of evidence, but little ends up as policy). Not recreational drug policy, foreign policy, housing, economy, transport...

We might all write to our MPs, expressing a wish that the minister will only act upon evidence, but an honest reply would say "what makes cycling policy so special that it needs to be based on facts?"

Fenix
Posts: 4
Joined: 28 Sep 2017, 2:30pm

Re: Searching for statistics and studies

Postby Fenix » 28 Sep 2017, 2:44pm

I've seen a few newspapers use the same quotes that seems to be based on a cycling uk report :

This is the gist of it - Between 2005 and 2015, some 32 pedestrians died and 820 suffered serious injuries after colliding with cyclists, according to a report by charity Cycling UK.

I think it comes from the FAQ about cycling - http://www.cyclinguk.org/sites/default/ ... ionsrv.pdf

Most collisions between cycles and pedestrians don’t happen on the pavement/verge, but in the
roadway, where it’s legal to cycle. From 2005-15, less than a fifth of the 32 pedestrian fatalities
and just over a quarter of the reported 820 serious pedestrian injuries that involved a cycle
happened on the pavement/verge. (Note: it isn’t possible to tell from these figures, which come
from the Department for Transport, who was at fault or, for those on the pavement, whether it
had been converted to ‘shared use’)


But this contradicts other data on the site - From 2011 to 2015 - 3 pedestrians were killed by cyclists

http://www.cyclinguk.org/campaigning/vi ... edestrians

So that means 2005 to 2010 29 pedestrians have been killed by cyclists ? These stats just dont add up and three newspapers at least have repeated them.

I always thought that pedestrian fatalities were about one per year from cyclists ? What's happened or gone wrong ?

AdamS
Posts: 146
Joined: 22 Apr 2010, 4:06am
Location: Lancs

Re: Searching for statistics and studies

Postby AdamS » 28 Sep 2017, 3:25pm

meic wrote:
Ultimately, we need to bear in mind that most people will read the excellent summary from the BMJ which tells them that even if they do wear a helmet it is unlikely to offer any kind of observable benefit, then choose to wear one because "it can't do any harm can it."

The number of people who have a problem with that are almost infinitely few.
It is when that somehow develops to "so I will force everybody to wear one" or even just the kids, that it becomes a problem.

Heavy and graphic promotiuon is a more immediate danger. It is only after greater voluntary adoption that compulsion could become a realistic option.I don't have a big desire to convince people not to wear their own helmets but even the "I'll wear one because it can't do any harm" attitude is potentially damaging because it erroneously treats cycling as different to other equivalently dangerous activities: https://beyondthekerb.org.uk/the-brick-wall/

If people get the idea that helmets are necessary this will influence their decisions about cycling. The perceived danger of cycling is a big barrier to people taking it up.Things like the discomfort of helmets, concerns about appearance (helmet hair etc.) and the inconvenience of carrying it around might not be huge deterrents but undoubtedly would make cycling a less attractive proposition for some.

User avatar
pjclinch
Posts: 4021
Joined: 29 Oct 2007, 2:32pm
Location: Dundee, Scotland
Contact:

Re: Searching for statistics and studies

Postby pjclinch » 28 Sep 2017, 3:56pm

bovlomov wrote:
pjclinch wrote:Public policy should be robustly evidence based and it should be logically consistent with other similar policies. Personal policy can be based on anything you want and needs no consistency.

I've always thought that the helmet debate was different from most others, in its total separation from reason. But how much public policy is robustly evidence based?


Very fair question. My use of the word "should" was quite deliberate!

Pete.
Often seen riding a bike around Dundee...

Steady rider
Posts: 2261
Joined: 4 Jan 2009, 4:31pm

Re: Searching for statistics and studies

Postby Steady rider » 28 Sep 2017, 7:15pm

mjr says;

If helmets do cause more crashes, whether through enlarging and weighting the head or through something else like impaired decision-making because you've wrapped your brain in insulating foam with holes that cause cold draughts when moving faster, then it really ought to be explored and explained. It's irresponsible to recommend a treatment that seems ineffective and hasn't been tested rigorously


I think one report tries to relate the potential benefits to disadvantages in accident terms,
http://www.ta.org.br/site/banco/7manuai ... helmet.pdf

The data suggests people may on average cycle perhaps say 5 hours per year at say 15 km/hr x 65 million = 4.9 billion km, I think the figure is about 5 billion km per year for the UK. Deaths are about 100 per year, roughly 20 deaths per billion km. or one per 50,000,000 km. Serious type injuries may be 50 times higher, but don't quote me, say one per 1,000,000 km.

The disadvantages of helmet use during these sort of time period?
Helmet mass say 250 gms, say hitting a road surface defect once every 1000km that generates a 5g force (deep pothole perhaps), where the helmet adds an extra random force to the head at a time of riding instability, say 1000 times in 1,000,000 km of riding. Hitting other things like kerbs or very rough surfaces can generate say 2-4g forces.
Consider wind effects and head turning, each time a helmeted head is turned the helmet may incur more side forces than a bare head, say 20% extra, slightly less stable riding conditions may result, say the head is turned every 5km of riding, 200,000 times in 1,000,000 km.
Consider the centre of gravity, 0.2% to 1% according the paper, the 1,000,000 km equates to 66,600 hours of riding, say cornering every 3km.
Consider if a rider thinks they are much safer with a helmet and rides slightly less careful on occasions, say once in 1000km or 1000 times in 1,000,000 km. Rider may feel safe and do higher risk type cycling.
Consider all of the above may combine for some cyclists, so the accident rate increases. (all above are estimates but based on research)

The benefits seem obvious, impact and it may help, but the overall accident rate is not obvious and difficult to appreciate how such small effects can lead to extra accidents.
Last edited by Steady rider on 28 Sep 2017, 7:32pm, edited 2 times in total.

User avatar
Cunobelin
Posts: 10775
Joined: 6 Feb 2007, 7:22pm

Re: Searching for statistics and studies

Postby Cunobelin » 28 Sep 2017, 7:31pm

mjr wrote:
meic wrote:The number of people who have a problem with that are almost infinitely few.

Like one of my teachers used to say, correctness isn't a popularity contest!

If helmets do cause more crashes, whether through enlarging and weighting the head or through something else like impaired decision-making because you've wrapped your brain in insulating foam with holes that cause cold draughts when moving faster, then it really ought to be explored and explained. It's irresponsible to recommend a treatment that seems ineffective and hasn't been tested rigorously.


Ironically BHIT reported the same

When they fiddled the figures to justify their compulsion stance it turned out that after compulsion, significantly more head injuries would occur then before.

User avatar
Cunobelin
Posts: 10775
Joined: 6 Feb 2007, 7:22pm

Re: Searching for statistics and studies

Postby Cunobelin » 28 Sep 2017, 7:37pm

Another useful paper is by Thornhill et al in Glasgow

It is a classic case where ALL head injuries were examined....

The characteristics of the cohort agreed with previous surveys1: 1255 (42%) were men aged 40 years or less, 575 (19%) were men and women aged 65 years or more, and most (90%) were classified as having a mild injury. The most common causes of injury were falls (43%) or assaults (34%); alcohol was often involved (61%), and a quarter reported treatment for a previous head injury


As with most cohort studies it is a clear example of reality, head injuries in cyclists are rare when compared with other groups... why are we only interested in preventing these injuries in a minority, when so many more could be prevented by looking at the groups where the head injuries actually occur

Steady rider
Posts: 2261
Joined: 4 Jan 2009, 4:31pm

Re: Searching for statistics and studies

Postby Steady rider » 29 Sep 2017, 10:56am

in 2013 police reported cycle accidents data shows 51% not wearing helmets, these including all accidents.

RobC
Posts: 118
Joined: 5 Feb 2008, 3:27pm

Re: Searching for statistics and studies

Postby RobC » 29 Sep 2017, 10:58am

This is a recent report using data from St Marys Hospital. The conclusion is "In a largely urban environment, the use of cycle helmets appears to be protective for certain types of serious intra and extracranial head injuries. This may help to inform future helmet design."

I've read it as a lay person - neither a doctor or a scientist - and it seems to be a compelling argument. I'm sure many of us agree that a helmet does provide a certain degree of protection for certain kinds of injury.

I don't actually wear a helmet - I don't believe the kind of cycling I do is any riskier than any other non-helmeted activity - but given that this study's conclusions are rather pro-helmet and will likely be used by the pro-helmet lobby as a result, I'm interested to know how to counter such arguments faced with research like this.

http://journals.plos.org/plosone/articl ... ne.0185367