> With regard to the use of bicycle helmets, science broadly tries to answer two main questions... “what is the effect of a public health policy that requires or promotes helmets?” and... “what is the effect of wearing a helmet?”

> The linked paper by Dennis and colleagues investigates the policy question and concludes that the effect of Canadian helmet legislation on hospital admission for cycling head injuries “seems to have been minimal

The linked editorial does not limit itself to discussing the impact of public health policy. It does start with a link to an article that attempts to quantify the effects of a Canadian helmet law. However, it then discusses a number of other papers and the general methodological issues with trying to estimate effects of wearing a helmet.

However, the article certainly does not endorse the claim you are responding to: "Bicycle helmets prevent neither concussions nor death"

The conclusion reached by the editorial is that the safety effects of helmet use are complicated and contingent which makes the results of any study of the effects highly dependent on the methodology. (There could be a positive effect in NYC but a negative effect in the Netherlands or a positive effect for riders of street bikes, but a negative effect for cruisers)

> In any case, the current uncertainty about any benefit from helmet wearing or promotion is unlikely to be substantially reduced by further research.

Incorrect. The article makes the strong and accurate claim that there has been no clear, measurable proof that helmets prevent concussion or death.

This should come as no surprise. When cyclists are hit by cars or trucks the force of the collision is generally so huge that the aorta are ruptured, internal organs (including the brain) are torn from their moorings, bones are cracked.

Helmets are incapable of preventing any of the above.

What _is_ capable of preventing such deaths is the removal of the private automobile from the public roads.

I am curious what part of the editorial leads you to draw that conclusion. The editorial specifically acknowledges that there is evidence that individual helmet use does reduce head injury rates. The entire point of the editorial is to discuss how to reconcile the individual use studies with the canadian helmet law study.

The point is not that "helmets don't pervent head injuries", but that helmets, and specifically, helmet focused public policy, have a marginal impact on safety and distract us from other more effective policy interventions.

> an emphasis on helmets reflects a seductively individualistic approach to risk management (or even “victim blaming”) while the real gains lie elsewhere. It is certainly true that in many countries, such as Denmark and the Netherlands, cyclists have low injury rates, even though rates of cycling are high and almost no cyclists wear helmets. This seems to be achieved through interventions such as good infrastructure; stronger legislation to protect cyclists; and a culture of cycling as a popular, routine, non-sporty, non-risky behavior.

Removing private automobiles from public roads is completely unnecessary to achieve much better bicyclist safety.

More cyclists wear helmets in those jurisdictions (parts of Canada, all of Australia and N.Z.) and yet ecological studies fail to clearly demonstrate any benefit from helmets. If you sprayed a field with RoundUp and saw no difference in the number of weeds compared to an unsprayed field you would start to wonder about the effects of the treatment.

And in doing so, it goes to some effort to explain why you cannot, from that, conclude that helmets have no effect on individual accident outcomes, all other things being equal. (Mainly because all other things aren't equal, and it's very difficult to devise a methodology that makes them so.)

Right. A friend who's an ER doctor once put it this way:

"I'm going to hit you in the head with a hammer; you can wear a bike helmet or not, your choice."

Statistics are all well and good, but it would take a rare allegiance to epidemiology to skip the helmet.

I've also heard it said that statistics look different when you are the statistic...

> an emphasis on helmets reflects a seductively individualistic approach to risk management (or even “victim blaming”) while the real gains lie elsewhere. It is certainly true that in many countries, such as Denmark and the Netherlands, cyclists have low injury rates, even though rates of cycling are high and almost no cyclists wear helmets. This seems to be achieved through interventions such as good infrastructure; stronger legislation to protect cyclists; and a culture of cycling as a popular, routine, non-sporty, non-risky behaviour.