Simplification to cut through the mis-perceptions?

[deliquium]

This whole helmet debate seems to get repetitively mired in mis-information and huge amounts of MUDDLE

Is there any statistical evidence which can demonstrate, that in the UK (at least), occupants of motor vehicles outnumber by x% (or a simple x figure), those of cyclists who are hospitalised due to head injuries?

Whether or not the cyclists were wearing helmets.

I've read/heard and even been told on fora that this might be the case?

If so - shouldn't this repeatedly be brought to wider attention?

Is it not beyond possibility that cycling is actually safer than being in a motor vehicle? And it's nothing to do with helmets

[drossall]

No, there aren't. First, this is not a logical, facts-based debate. It's emotive, and those promoting helmets are often coming from approximately the line that heads are important, and helmets are made to protect heads, so helmets must be a good thing. The answer that they don't actually seem to do that is so unexpected as not to really get a meaningful response, except to cite an anecdote in which an accident was survived when wearing a helmet. The need to demonstrate whether the helmet made a difference is not really perceived.

Second, statistics are more complex than you envisage. You can't compare cars and bikes without thinking about exposure - if cars are used more than bikes, then you could expect more car occupants to end up in hospital, even if cars were somewhat less risky. Then, however, you get into a debate of how to compare risk. Cars are faster than bikes. Do we compare per hour of use, or per mile? This leads to impassioned, if somewhat sterile, debate even among those who doubt the efficacy of helmets (and makes a significant difference to the answer).

Overall, cars come out somewhat safer when you consider these factors. There are more motoring casualties than cycling because of the high level of car usage, not because cars are more risky (to their occupants). However, the difference is not as much as you might think, and quite large differences in low risk arguably aren't as significant as they appear. Most people regard going to town in their cars as pretty acceptably safe. Make it tens times more dangerous and they might still be happy (because the chances of accident would still be quite low).

Hence, the risks of cycling are not that great on the measures used by most people. But, it's an emotive subject, and, "Cycling is dangerous, isn't it."

Where's my helmet?

[deliquium]

^ Thanks drossall - and sorry, being naive and frustrated at the force of the pro helmet lobby

[Mick F]

Yes, a good piece about the "issue".
Thanks drossall.

However, I feel there could be a simple and bare percentage figure for head injuries in cars and on bicycles.
The figures must exist.

[pjclinch]

Well, not really...

As drossall notes, statistics concerning complex issues are more complex than we'd like, or than people often think. Aside from things like differences in exposure already mentioned, bottom-line casualty figures for "cyclists" take little account of what sort of cyclist. Sporting riders not only have greater exposure but take greater risks, for example, and if you spin off a group of "helmet wearers" it still isn't representative, because you mix groups who are wearing because they're managing greater risks with those who are wearing because they are risk averse, and so on. This is only the tip of the iceberg: I'm no stats expert, but I do science on a professional basis and I think I have a fair grasp of when stats run in to problems and warning bells start to ring.

The figures must exist.

42.
There you go.

You just have to work out exactly (and I really do mean exactly) what the question is. And that question has to include sufficient context that A Notional Random Cyclist can be sure it applies to him/her on the particular road and particular time. And so on. It's a very complex question, and the only simple answer that works with most complex questions is, "it depends...".

Pete.

[Mick F]

Life, the Universe, and Everything.

Still, I would like the the bare percentages ............... just for interest, not for Anything Else.

Let's say there are 1M cyclists, and 10M car occupants on any one day.
Multiply that by 365.
How many head injuries in each section sustained during the activity/journey per year?

[drossall]

How would you like us to get the answer? For cycling, for all cyclists, or just for those on road, or just for those in cities, or for World Tour races, or for competitive riders including in training (let's say World Tour riders because it would be easier to define, but could be any), or excluding anything relating to competition but including touring and long distance?

And for driving, by analogy, for all travel, or excluding motorways (where cyclists can't go), or excluding dual carriageways too (where few cyclists go), and do we include competitive motorsport (because of the inclusions for cyclists) and put in a factor for off-road driving?

Do we put in a factor because cyclists include children, whose riding patterns and risk factors are almost certainly different from those of adults, and who are not, of course, allowed to drive cars?

And once we've answered those questions, how do we work out the total mileages for qualifying drivers and cyclists with any accuracy? How do we compensate for the fact that traffic counts and other measurements happen mostly on roads with more traffic (where cars are over-represented by comparison with cyclists), and the lack of information on total journey length for either mode?

Once all that's done, I think I've read that guesses are that cycling is probably ten to 100 times more dangerous per mile*, but someone will be along to comment on that, no doubt. I'm pretty sure it's not 1000. And, as I said before, you need to consider the absolute risk. Frankly, even if something is 1 million times more likely than my being struck by a falling comet, I'm not sure I should lose any sleep over it. Now driving and cycling are both more dangerous than that, but I'm confident that neither is risky enough (to me) to lose sleep over either. (Which doesn't mean I shouldn't be careful.)

Probably the most useful guesstimate I've heard is that the medical profession have supported estimates that the health benefits of cycling outweigh the risks by about 20:1. From that perspective, driving is more dangerous than cycling, because it has no such health benefits. For that matter, it means that not cycling is much more dangerous than cycling, and possibly by a greater difference than cycling is more dangerous than motoring.

Pick a statistic to suit...

* Which relates to the point I mentioned before. Should we measure per mile or per hour of exposure? Arguably, if you're asking about the best way to work, which is a fixed distance, per mile makes more sense. However, for discretionary journeys, you may decide whether to go on the basis of how many hours it will take, so maybe per hour makes more sense; it's also less affected by cars doing many miles on relatively-safe motorways from which bikes are excluded.

[deliquium]

I guess I'm looking for a kind of "Trumpism" ( ) or at least a soundbite - cos that's what seems to get through to people - WITH numbers as a descriptor.

We can relate to ^ them (both). We learned them (numbers) from a very early age. We live our lives by them and make huge decisions cos of them.

Every helmet thread ends in a muddle/mess.

It's a struggle worth enduring (I believe). As cyclists and citizens, we surely don't need more laws nor MORE helmets? They both miss the point spectacularly.

So how can we counter the pro LOBBY with simple arguments, rather than the muddle we see on here and other places?

Our message isn't getting across - we NEED to make it simpler?

[drossall]

I guess I'm looking for a kind of "Trumpism"...

Oh, but that's a post-truth question. You just make one up, surely?

Doesn't help in reducing road casualties, but makes your point.

[Wanlock Dod]

I think that perhaps one of the most important aspects is that there isn't really any discussion being had. I think that this is principally because it is so obvious to so many people that helmets are both effective and necessary that they consider anybody suggesting otherwise to be a bit of a crackpot. If there really is an extensive body of research surrounding the lack of helmet usefulness then it is clear that nobody is really putting any effort into getting the word out. Helmets must, therefore, be both effective and necessary.

[Mick F]

How would you like us to get the answer?

Like I asked.
How many head injuries are sustained with car occupants, and with cyclists?

ie car occupants when travelling and cyclists when cycling.

[Mike Sales]

Are you serious?
Ben Goldacre, Wellcome research fellow in epidemiology, and David Spiegelhalter,Winton professor for the public understanding of risk examined the evidence for helmet efficacy.
In the BMJ they wrote,
"In any case, the current uncertainty about any benefit from helmet wearing or promotion is unlikely to be reduced by further research. Equally we can be certainthat helmets will continue
to be debated, and at length. The enduring popularity of helmets as a proposed major intervention for increased road safety may therefore lie not in their direct benefits- which seem too modest to capture compared with other strategies- but more with cultural, psychological, and political debate around risk."

[Mike Sales]

I think that perhaps one of the most important aspects is that there isn't really any discussion being had. I think that this is principally because it is so obvious to so many people that helmets are both effective and necessary that they consider anybody suggesting otherwise to be a bit of a crackpot. If there really is an extensive body of research surrounding the lack of helmet usefulness then it is clear that nobody is really putting any effort into getting the word out. Helmets must, therefore, be both effective and necessary.

My 7:30 post was addressed to you. I recommend Goldacre's Bad Science website and cyclehelmets.org for readng.

[RickH]

I'm not sure that, for whatever reason, there are the statistics brought together to show what is happening. A bit of Googling on my part brought up the following. And simple it doesn't seem to be, unless someone with more skills in data analysis & finding the data can attack this & the other stats that are probably lurking somewhere else.

DfT Reported Road Casualties Great Britain 2015 - Main results (PDF) & infographic (PDF) - give some overall info. The Main Results document links to lots of stats (here). But, unless I've missed it, there doesn't seem to be an analysis by injury type.

This table (ODS document), showing Killed/ KSI/ all severity data by road user type, may be of some relevance.

My observations (if I've done my calculations right) from a brief look
60% of all injuries were car occupants / 43% of deaths (if those statistics were for some other aspect of the transport network - say the railways or the buses - there would be a national outcry!)
Proportions of those killed / Seriously Injured, within each user type compared to total reported for that type,
car occupants 0.7% / 7% SI
cyclists 0.5% / 17% SI (lower rate of deaths but significantly higher proportion seriously injured)
ped 1.6%/ 20% SI (higher proportion killed & higher proportion SI)
motorbike 1.8% / 25% SI (higher proportion again killed & even higher proportion SI)

10% of all reported injuries were cyclists, 13% were pedestrians (5% / 24% of deaths respectively). The figures will be affected by the fact that cyclists are often on the road & pedestrians are mostly off the carriageway (but will be wanting to cross).

To put road deaths in context - this document (ODS) shows, in 2014, 14% of accidental deaths & 0.4% of all deaths were registered as road deaths.

This (somewhat older) analysis (PDF) compares head injuries with non-head injuries (but doesn't include cyclists. Were levels too insignificant to include?) Table 3.7 on p 18 compares head injury rates to rates of other injuries.

Note: it does seem to make a few sweeping "helmets are good" assumptions in the text such as:-

Of the fatal casualty records with injury descriptions, about 64% had multiple injures and 26% had a single injury noted. While there is no indication of the severity of any one injury, 72% of those with single or multiple injures had suffered a head injury thus underlining the importance of their prevention and treatment.

My observation - or was the "head injury", at least in some instances, of little consequence to the survivability of their injuries? I'm not sure we can really tell without more info.

The proportion of motorcyclists with head injuries is low, reflecting the protective effect of hard helmets. The proportion and number of pedestrians with head injuries is very high, reflecting the absence of available countermeasures to protect the head in collisions involving pedestrians.

My observations - do motorcyclists hit their head infrequently (perhaps like cyclists - if you ever watch motorcycle racing they often slide, then get up & walk away) if they don't actually hit anything solid while sliding? Walking helmets anyone?

Enough waffling on (for now at least) ......

[horizon]

Well, not really...

As drossall notes, statistics concerning complex issues are more complex than we'd like, or than people often think.

The statistics might be difficult but for the man in the street there are three simple facts:

1. You can seriously hurt your head if you fall from a height or at speed.
2. Material can cushion a blow.
3. Cycle helmets do precisely that.

That makes every man and his dog an expert and no further information is required. Indeed, if it is presented, it will be seen as silliness, moral irresponsibility or deliberate obfuscation. The pro-helmet side is very accessible: everyone knows what tarmac feels like, everyone knows how a head hurts, everyone knows what a cycle helmet looks like, everyone knows what a bicycle is and how fast is goes. For the average person, this is not a complex or difficult subject, it's an open (and then very firmly closed) book. In fact, they would say that looking at statistical evidence is simply wrong. Don't think, act. I think children often have thoughts, reflections and doubts that are over-ridden by parental admonition (albeit sometimes for good reason - don't be silly, jump in the pool now!). But that pattern seems to play itself out with helmets - don't be silly, just put your helmet on - be grown up. The internal parental voice (as well as the social voice) then kicks in when the cyclist is an adult.

I would agree with the poster above - we do need a soundbite or image which comprehensively shows that helmets don't work.