Airbag for cyclists.

alansmurphy wrote:

The part I disagree with Rich is using any data from a group that confirms that wearing a hi viz jacket prevents you falling off your bike!

 

The recognised methodology they should be using is deleting all the data.

 

And 2/3rds wearing a jacket - being aware that they aren't all early/late riders - c'mon open your eyes...

You claim to have some understanding of research methodology.

The above post contradicts that somewhat.

Bias is unavoidable in unblinded studies.

In this study that bias manifests itself as an undereporting of accidents in the yellow jacket group.

The authors identified the bias and controlled for it using a recognised published technique.

You might not agree with that technique but unless your criticism amounts to more than just calling it 'bollocks' I'm afraid it doesn't carry much weight and, ironically, is probably just a reflection of your own bias.

alansmurphy wrote:

I like that you can use 'Control C' and 'Control V' but their adjustment is frankly bollocks. It is now you that is looking for something to support your predetermined viewpoint and ignoring what goes against it.

 

If nearly half of your sample are talking shit about the incidents then you're in trouble. If 2/3 are claiming they wear the jacket in August then you're in trouble when analysing the data. Simple really.

 

Again, like the helmet debate, I wear hi viz. I'm about to leave work and put on Northwave reflective shoe covers, a high viz flashing strap on each leg, an Altura nightvision reflective jacket, have reflective detailing on the galibier gloves. None of this will prevent me falling off my bike, it simply makes me feel more likely to be seen or gives the tw@t that knocks me off many more items to try and throw over a hedge for his SMIDSY defence.

The authors are using a recognised technique to control for the inevitable bias that all research encounters in unblinded studies.

You claim that the adjustment is 'bollocks'. Care to elaborate? Which part do you disagree with?

Also, according to Wikipedia, the average July temp in Denmark is a balmy 17 degrees. Mornings and evenings are likely to be cooler so it's not inconceivable that people might wear a jacket.

alansmurphy wrote:

Thanks, I have a basic grap of statistics and research methodology.

 

What I'm telling you is the methodology and the outcomes demonstrates a huge bias hence the rest of the outcomes will suffer from this.

 

Unless you can explain how wearing a high viz jacket reduces the 'nobody else involved' incidents by nearly a half, you cannot expect anyone to take the rest of the results seriously...

If only the authors had noticed that.

They may have devoted an entire section to explaining how they controlled for the inevitable bias.

It may have gone something like this:

"The bicycle jacket is expected to influence the number of multiparty PIAs, whereas the number of single PIAs is not likely to be affected by jacket wearing. Therefore, any difference between the test and control groups indicates a potential reporting bias between the groups, which may occur because the study is non-blinded, and the participants know whether they belong to the test or control group. We adjusted for potential report bias as suggested by Madsen et al. (2013) by correcting the risk of multiparty PIAs in the control group, using a correction factor equal to the estimated ARR for single PIAs as a general correctional factor

The index j refers to type of accident (e.g. winter accidents) and the index C means “Control group”. Specifically,
with data from Table 3, Table 4.

This correctional factor was multiplied by the reported number of PIAs in the control group, thus reducing the number of PIAs in the control group caused by the likely underreporting of PIAs in the treatment group (Madsen et al., 2013). The corrected ARs for the control group were estimated in the following way:

In practice, the corrected analysis was based on an estimate of a corrected ARR given by the relative difference between the multiparty ARR and the single ARR:

As the ARRs are likely to be skewed, the standard errors are usually estimated through a transformation to the logarithmic scale. The standard error of the corrected ARR of multiparty PIAs on the logarithmic scale was given by:

And the formula of the 95% confidence interval on the logarithmic scale:

The 95% limits were then back-transformed. In practice, the standard error on a logarithmic scale can be estimated in the following way:
where X denotes the number of PIAs, i is either “multiparty” or “single” and T denotes the test group and C the control group."

alansmurphy wrote:

Further into the study it shows that there are seasonal variations on jacket use, November had the highest proportion wearing (well it is colder and darker) and July the lowest at only 67%. What? Are you seriously suggesting that in the middle of summer 2 in 3 riders were wearing a jacket?!

Must have been cycling in Scotland 

alansmurphy wrote:

Further into the study it shows that there are seasonal variations on jacket use, November had the highest proportion wearing (well it is colder and darker) and July the lowest at only 67%. What? Are you seriously suggesting that in the middle of summer 2 in 3 riders were wearing a jacket?!

Surely the sort of nodder that dresses like a traffic island year round is exactly the sort of person that would agree to be part of a study like this!

Simon E wrote:

FFS. What's next? Compulsory airbags for people on stairs?

I fail to see what point you're making.

Should all inventors be forced to work on stair safety before they're allowed to invent anything else?

This is an innovative product that has the potential to reduce deaths and injuries.

Why get so worked up about it?

Rich_cb wrote:

This is an innovative product that has the potential to reduce deaths and injuries.

Do you honestly believe that?

All I see is a cynical way of making money out of PPE when it would be effective only in a tiny number of collisions. Look at the number of people who die falling from stairs & ladders - why is no-one flogging helmets and comedy inflatable lifejackets to those people?

Just like helmets, we will get to a point a cyclist is killed or injured without wearing one then insurance companies (and all the fools who swallowed the hype) will claim the victim is at fault for not protecting themselves when in fact it's drivers that need to do something to prevent the collisions in the first place. Like slowing down, putting their mobile away or, god forbid, stop acting like they own the fucking road.

If you don't see this as a problem then fine, go and buy one. No-one is stopping you waste your money. Wear it along with your ineffective polystyrene hat with its 'cry wolf' crash detection beacon, your hi-viz, your reflectives, your useless brake lights and indicators, your St Christopher bracelet and any other lucky charm you think might help. But none of it will work. I will fight it because I'm sick to death of this pattern of exploiting (and scapegoating) the victims on the road and pretending that the same old problem of cars crashing into people can be fixed with yet another new gadget for cyclists to buy.

Simon E wrote:

Rich_cb wrote:

This is an innovative product that has the potential to reduce deaths and injuries.

Do you honestly believe that?

All I see is a cynical way of making money out of PPE when it would be effective only in a tiny number of collisions. Look at the number of people who die falling from stairs & ladders - why is no-one flogging helmets and comedy inflatable lifejackets to those people?

Just like helmets, we will get to a point a cyclist is killed or injured without wearing one then insurance companies (and all the fools who swallowed the hype) will claim the victim is at fault for not protecting themselves when in fact it's drivers that need to do something to prevent the collisions in the first place. Like slowing down, putting their mobile away or, god forbid, stop acting like they own the fucking road.

If you don't see this as a problem then fine, go and buy one. No-one is stopping you waste your money. Wear it along with your ineffective polystyrene hat with its 'cry wolf' crash detection beacon, your hi-viz, your reflectives, your useless brake lights and indicators, your St Christopher bracelet and any other lucky charm you think might help. But none of it will work. I will fight it because I'm sick to death of this pattern of exploiting (and scapegoating) the victims on the road and pretending that the same old problem of cars crashing into people can be fixed with yet another new gadget for cyclists to buy.

I do honestly believe that and you seem to agree with me.

There is very good evidence for the effectiveness of high visibility and daytime lights.

In an ideal world we wouldn't need anything at all but we don't live in an ideal world, you can choose to protect yourself against the less than ideal circumstances we face or you can choose not too. It's entirely your choice.

Rich_cb wrote:

 I do honestly believe that and you seem to agree with me.

I'm not sure I do.

PPE should be a 'last resort' not the first thing we try. Just because a vest thing might work in rare cases is not a good reason to flog them to every person that rides a bike.

Rich_cb wrote:

There is very good evidence for the effectiveness of high visibility and daytime lights.

Is there?

Daytime lights - promoted heavily by the manufacturers, as with helmets - are not a solution. In fact I believe that the widespread use of daytime lights on cars is counterproductive and makes it harder to spot less conspicuous vehicles, objects and people. Since these lights are very widely used on modern cars why have we not seen a significant drop in daytime collisions on our roads? As I read in a recent article, most people who push this quote a single 2005 Danish self-reported study (in the writer's words, "not worth the paper they're written on"), the results of which have not been repeated since. Plenty of so-called scientific studies are anything but objective.

While hi-viz might make you stand out in some circumstances it is not a solution. Cyclists still get SMIDSY or hit while wearing hi-viz and it's useless in the dark. If it is so effective (which surely suggests that non-hi-viz clothing is not) then why don't cyclists wearing black get mown down on their first ride?

Rich_cb wrote:

In an ideal world we wouldn't need anything at all but we don't live in an ideal world, you can choose to protect yourself against the less than ideal circumstances we face or you can choose not too. It's entirely your choice.

It's not an ideal world but the problems we face on the road won't go away just because we buy unproven gadgets which we know are very unlikely to make a real difference to the outcome of a collision and at the same time reinforce the widespread and erroneous perception that cycling is a dangerous activity. And that's before we mention risk compensation.

If you're that keen on all this protective equipment why not just drive a car? Though even with all the gizmos and 2 tonnes of steel cage around them more car occupants are killed or injured each year than any other road user category. So why haven't all the safety features added to modern cars signifcantly reduced the collision statistics?

Please let us know how you get on with your airbag. I could do with a laugh.

Simon E wrote:

PPE should be a 'last resort' not the first thing we try. Just because a vest thing might work in rare cases is not a good reason to flog them to every person that rides a bike.

Daytime lights - promoted heavily by the manufacturers, as with helmets - are not a solution. In fact I believe that the widespread use of daytime lights on cars is counterproductive and makes it harder to spot less conspicuous vehicles, objects and people. Since these lights are very widely used on modern cars why have we not seen a significant drop in daytime collisions on our roads? As I read in a recent article, most people who push this quote a single 2005 Danish self-reported study (in the writer's words, "not worth the paper they're written on"), the results of which have not been repeated since. Plenty of so-called scientific studies are anything but objective.

While hi-viz might make you stand out in some circumstances it is not a solution. Cyclists still get SMIDSY or hit while wearing hi-viz and it's useless in the dark. If it is so effective (which surely suggests that non-hi-viz clothing is not) then why don't cyclists wearing black get mown down on their first ride?

It's not an ideal world but the problems we face on the road won't go away just because we buy unproven gadgets which we know are very unlikely to make a real difference to the outcome of a collision and at the same time reinforce the widespread and erroneous perception that cycling is a dangerous activity. And that's before we mention risk compensation.

If you're that keen on all this protective equipment why not just drive a car? Though even with all the gizmos and 2 tonnes of steel cage around them more car occupants are killed or injured each year than any other road user category. So why haven't all the safety features added to modern cars signifcantly reduced the collision statistics?

Please let us know how you get on with your airbag. I could do with a laugh.

A good attempts to cram as many logical fallacies as you can into just one comment. Kudos.

If something doesn't work 100% of the time that doesn't make it ineffective.

Likewise if it is possible to complete a ride dressed head to toe in black without dying that doesn't mean it is as safe as wearing brighter clothing.

The studies demonstrating the benefit of high visibility and daytime lights were both large randomised controlled trials. The highest quality evidence available in this context. Your personal hunches don't really compare.

I do agree that PPE should be a last resort but unless something changes dramatically over night when I head out on my bike tomorrow morning I will be down to that last resort as it will be impossible for me personally to change a single other risk factor before I set off.

Rich_cb wrote:

If something doesn't work 100% of the time that doesn't make it ineffective.

But saying "not always effective" or "will only help in certain crash scenarios" aren't great sales lines. How far down the road of "if it saves one life" should we go? Full leathers and a motorcycle helmet? That's going be better than 0.3mm of lycra and a 200g hat full of holes, isn't it?

Rich_cb wrote:

if it is possible to complete a ride dressed head to toe in black without dying that doesn't mean it is as safe as wearing brighter clothing.

I was posing the question in a provocative way but I feel it's a valid point: why do people wearing hi-viz still get hit? And do riders in black get knocked off more than those wearing brighter colours? If so then are the clothing brands irresponsible for selling it?

Rich_cb wrote:

The studies demonstrating the benefit of high visibility and daytime lights were both large randomised controlled trials. The highest quality evidence available in this context. Your personal hunches don't really compare.

Do you have links to any of this research? I'm prepared to revise my opinion if it is convincing.

You think the airbag is a good idea, apparently without that kind of evidence. So it's fine for others to buy stuff based on marketing hype but I can't go with a scepticism resulting from decades of experience, a 'gut feeling' based on my research and experience?

Will you wear an airbag once they become available?

Simon E wrote:

But saying "not always effective" or "will only help in certain crash scenarios" aren't great sales lines. How far down the road of "if it saves one life" should we go? Full leathers and a motorcycle helmet? That's going be better than 0.3mm of lycra and a 200g hat full of holes, isn't it?

I was posing the question in a provocative way but I feel it's a valid point: why do people wearing hi-viz still get hit? And do riders in black get knocked off more than those wearing brighter colours? If so then are the clothing brands irresponsible for selling it?

Do you have links to any of this research? I'm prepared to revise my opinion if it is convincing.

You think the airbag is a good idea, apparently without that kind of evidence. So it's fine for others to buy stuff based on marketing hype but I can't go with a scepticism resulting from decades of experience, a 'gut feeling' based on my research and experience?

Will you wear an airbag once they become available?

For me it's a balance between safety and comfort.

It's been pretty cold recently so I've been wearing a gilet, do I care what colour my gilet is? Not really. So my comfort is identical but my safety is improved.

Full leathers and a motorcycle helmet would probably improve safety in a collision but would be very uncomfortable so not really an option.

People in hi viz still get hit because the majority of all collisions are not preventable by the cyclist. All we can do is focus on the collisions we can prevent through good equipment and good road craft.

I think equipment that only protects the cyclist, eg helmet, high visibility, should not be compulsory and as such while I wouldn't personally go out in the dark dressed entirely in black I think others should be free to do so.

I think the airbag is a good idea without research as it's literally just been invented so gut feeling is all I have to go on, I probably won't buy one now but may buy a future iteration once the evidence is available.

Research:
https://www.sciencedirect.com/science/article/pii/S0925753517313528

Rich_cb wrote:

Simon E wrote:

But saying "not always effective" or "will only help in certain crash scenarios" aren't great sales lines. How far down the road of "if it saves one life" should we go? Full leathers and a motorcycle helmet? That's going be better than 0.3mm of lycra and a 200g hat full of holes, isn't it?

 

I was posing the question in a provocative way but I feel it's a valid point: why do people wearing hi-viz still get hit? And do riders in black get knocked off more than those wearing brighter colours? If so then are the clothing brands irresponsible for selling it?

 

Do you have links to any of this research? I'm prepared to revise my opinion if it is convincing.

 

You think the airbag is a good idea, apparently without that kind of evidence. So it's fine for others to buy stuff based on marketing hype but I can't go with a scepticism resulting from decades of experience, a 'gut feeling' based on my research and experience?

Will you wear an airbag once they become available?

For me it's a balance between safety and comfort. It's been pretty cold recently so I've been wearing a gilet, do I care what colour my gilet is? Not really. So my comfort is identical but my safety is improved. Full leathers and a motorcycle helmet would probably improve safety in a collision but would be very uncomfortable so not really an option. People in hi viz still get hit because the majority of all collisions are not preventable by the cyclist. All we can do is focus on the collisions we can prevent through good equipment and good road craft. I think equipment that only protects the cyclist, eg helmet, high visibility, should not be compulsory and as such while I wouldn't personally go out in the dark dressed entirely in black I think others should be free to do so. I think the airbag is a good idea without research as it's literally just been invented so gut feeling is all I have to go on, I probably won't buy one now but may buy a future iteration once the evidence is available. Research: https://www.sciencedirect.com/science/article/pii/S0925753517313528

Wow - that research shows an unreasonably large effect from the hi-viz - 38% reduction.

You're right about the safety/comfort balance (though maybe safety/comfort/price might be more accurate in this instance), but I'm really not convinced by torso protection on a bike. It would probably make more sense for me to wrap loads of bubble wrap around the street furniture alongside my regular routes (cheaper too).

HawkinsPeter wrote:

Rich_cb wrote:

 Research: https://www.sciencedirect.com/science/article/pii/S0925753517313528

Wow - that research shows an unreasonably large effect from the hi-viz - 38% reduction.

That is a very large effect! If you take this figure and add the data from the Daytime Conspicuity Benefits of Fluorescent Bicyclist Apparel (https://journals.sagepub.com/doi/abs/10.1177/1541931213601954) that would mean that wearing hi-vis leggings makes you pretty much invulnerable. Why are there not many of these on the market?

HawkinsPeter wrote:

Wow - that research shows an unreasonably large effect from the hi-viz - 38% reduction.

This is an interesting comment.  Do you have a problem with the study design/methodology, does it conflict with previous research you are aware of, or is just that the result is not in keeping with what you imagined it to be in your head?

stomec wrote:

HawkinsPeter wrote:

Wow - that research shows an unreasonably large effect from the hi-viz - 38% reduction.

This is an interesting comment.  Do you have a problem with the study design/methodology, does it conflict with previous research you are aware of, or is just that the result is not in keeping with what you imagined it to be in your head?

It just conflicts with what I'd expect. I would have guessed that hi-viz would maybe have a 10% effect at best. As I currently cycle a lot at night, I prefer to go with reflectives (especially the 3M high reflective stickers).

I haven't drilled down into the study design/methodology though I did spot that it wasn't a blinded study (presumably they kept falling off when they were blinded).

stomec wrote:

Do you have a problem with the study design/methodology, does it conflict with previous research you are aware of, or is just that the result is not in keeping with what you imagined it to be in your head?

whatever research wrote:

The accident rate (AR) (accidents per person month) for personal injury accidents (PIAs) for the test group was 47% lower than that of the control group. 

So just putting a high viz jacket on makes you only around half as likely to fall off your bike (PIAs seemingly being accidents not involving another road user).

So if i put it on, take it off, put it on, take it off and put it on again then I'm invincible!

Brilliant!

alansmurphy wrote:

So just putting a high viz jacket on makes you only around half as likely to fall off your bike (PIAs seemingly being accidents not involving another road user).

 

So if i put it on, take it off, put it on, take it off and put it on again then I'm invincible!

 

Brilliant!

It is impossible to blind the participants in this particular study.

Bias is inevitable in unblinded studies.

The authors identified and controlled for the unavoidable bias.

The analysis was carried out using 'intention to treat' hence the inclusion of those who chose not to wear the jacket.

https://en.m.wikipedia.org/wiki/Intention-to-treat_analysis

hirsute wrote:

Car drivers and their passengers should be made to wear a Bibendum outfit - excellent idea! 

brooksby wrote:

hirsute wrote:

Car drivers and their passengers should be made to wear a Bibendum outfit - excellent idea! 

This is only the 2nd time I've ever seen someone use Michelin man's proper name - the other being in the legendary 'The Great Bike Race'. Kudos!