Jumbo-Visma to wear helmets with “healthy brains” at Paris-Roubaix to encourage helmet wearing

They're not limited Burt.

They're the most useful studies of helmet efficacy and will actually underestimate the efficacy of helmets to prevent injury.

Paul J wrote:

The point of meta-analyses is to minimise scope for manipulation. So the search method and inclusion/exclusion criteria should be pre-set and objective, etc. That helmets would reduce serious head injuries by 60% seems quite believable to me. In line with other meta-analyses I've read. The thing is that that serious head injuries are _rare_ (least, without other life-threatening injuries). So a 60% reduction is a reduction from one small number to another slightly smaller number. I remember discussing this with a doctor at a cycling org once, and he didn't agree with my view. He looked up injuries in his data at his cycling org and found something like 2 serious head injuries out of (IIRC) ~620 injuries overall in accidents his organisation had recorded. With a 60% reduction due to helmets, that means that without helmets, there would have been 621 injuries in total, with 3 serious head injures. The helmets saved *1* serious head injury out of 621. A large reduction in a tiny number is a /very slightly/ tinier number. Basic arithmetic.

Meta analyses do minimise scope for manipulation if, and only if, the criteria for inclusion is wide enough to include contrary research, not just research that supports the view of those doing it.  The most egregious example of this not happening is the Cochrane Study done by Thompson, Rivara and Thompson (the most zealous helmet promoters in the world) who excluded anything which didn't support their views, used mostly their own research and surprisingly found that helmets were effective.  They broke every rule of Cochrane Studies whilst doing so, but it didn't seem to bother anyone.  There are other examples of helmet meta-studies doing the same, hence my suspicion of them.

The study used to justify this campaign isn't publicly available and it is impossible to see what their criteria for inclusion were or the studies they chose: therefore I am hesitant to take the findings at face value.

Most original research with robust methodology finds that there is no benefit from helmet wearing.  Studies with less robust methodology find great benefits, and most meta-studies seem to select that type of research rather than the more robust.  As I've said already, putting lots of bad science together doesn't suddenly make it good.

eburtthebike wrote:

Most original research with robust methodology finds that there is no benefit from helmet wearing.  Studies with less robust methodology find great benefits, and most meta-studies seem to select that type of research rather than the more robust.  As I've said already, putting lots of bad science together doesn't suddenly make it good.

For context, Burt doesn't believe in the hierarchy of research evidence so his definition of 'robust methodology' should be taken with enough salt to worry a Cochrane review on high blood pressure.

While population studies are usually considered low quality evidence, they can be useful if the population remains otherwise virtually unchanged during the study period.

With the large changes in the cycling population that we know occur after mandatory helmet laws they offer very little value at all.

Rich_cb wrote:

eburtthebike wrote:

Most original research with robust methodology finds that there is no benefit from helmet wearing.  Studies with less robust methodology find great benefits, and most meta-studies seem to select that type of research rather than the more robust.  As I've said already, putting lots of bad science together doesn't suddenly make it good.

For context, Burt doesn't believe in the hierarchy of research evidence......

I am quite happy that long term, whole population studies are more valid than case control studies, but doubtless you differ.  Strangely, almost all the hierarchies of research methodology seem to ignore long term, large scale, whole population studies, with most of them saying that meta-studies are the most valid.  As I've already shown, that isn't the case, and meta-studies can and have been manipulated, so you are right, I disagree with hierarchies.  Properly conducted meta-studies with disinterested researchers are fine, it's just that there are plenty of helmet studies where that isn't the case.

They ignore "long term, large scale, whole population" studies because they are of very little value.

The most basic principle of medical research is that the two populations you are comparing have to be similar, as similar as possible.

As 'whole populations' vary considerably over time there is limited value in studying the 'long term' differences.

We know that the cycling populations pre and post mandatory helmet laws are very different which eliminates what little value population studies offer.

So to summarize, case control helmet studies are crap, population helmet studies are crap.
Conclusion let's stop blathering on about helmets and focus on the stuff that actually works, pushing back against individual motorisation, building good public transport and good cycling and walking infrastructure.

I'd disagree that case control studies are 'crap'. A well designed case control study will produce high quality evidence.

I agree that all those measures will be more effective systematically but on an individual level there aren't many options available to a cyclist. The roads are unfortunately dangerous enough that PPE is a valid choice for most cyclists so discussing the efficacy of the most commonly used piece of cycling PPE is a valid exercise.

Awavey wrote:

a Dutch team, with a Dutch sponsor (Jumbo not Lazer obv), not sure I understand why theyve done this

To sell helmets.  As the old saying goes "When you don't understand what's going on, follow the money."

well maybe I was taking the more philosophical angle

I mean look Lazer make this Wout Van Aert limited edition which wont and hasnt received half as much attention https://www.lazersport.com/uk/stories/win-like-wout and is a much more subtle attempt to sell stuff, especially as he doesnt even wear it in races opting for the traditional Red Bull sponsor colours.

but even if you go over to the JumboVisma shop, whilst they sell all kinds of branded stuff you didnt know you needed, you cant buy this helmet.

and JumboVismas core market is Belgium/Holland right, its not us in the UK for sure. Well the Dutch arent going to take any notice of this, and Im not I sure I know what the Belgians think of cycling helmets, but lets presume it splits like normal and the flemish will side more with the Dutch and the Walloons with the French and the Brusselians dont have an opinion on it.

so sure its to sell helmets, but to whom ?

Awavey wrote:

well maybe I was taking the more philosophical angle

I mean look Lazer make this Wout Van Aert limited edition which wont and hasnt received half as much attention https://www.lazersport.com/uk/stories/win-like-wout and is a much more subtle attempt to sell stuff, especially as he doesnt even wear it in races opting for the traditional Red Bull sponsor colours.

but even if you go over to the JumboVisma shop, whilst they sell all kinds of branded stuff you didnt know you needed, you cant buy this helmet.

and JumboVismas core market is Belgium/Holland right, its not us in the UK for sure. Well the Dutch arent going to take any notice of this, and Im not I sure I know what the Belgians think of cycling helmets, but lets presume it splits like normal and the flemish will side more with the Dutch and the Walloons with the French and the Brusselians dont have an opinion on it.

so sure its to sell helmets, but to whom ?

My observation when riding in Flanders is that people in Lycra riding curly handlebarred bikes wear helmets and most 'civilians' don't.