Raise the Hammer

The problem is that flawed studies such as this convince politicians to introduce bicycle helmet laws. This discourages cycling, reduces safety in numbers and increases the risk of some stupid driver hitting you, despite the attention you devote to the traffic around you!

The biggest flaw in this and other studies is that it compares cyclists who die of head injuries with cyclists who die of other injuries.

The real test should be to compare cyclists who die of head injuries with uninjured cyclists - i.e. the cycling population. This provides a more sensible estimate of the risk to the average helmet wearer vs non-wearer.

In Holland, cyclists who wear helmets are much more likely to be injured and end up in hospital that non-wearers - http://www.cyclehelmets.org/1261.html

It's natural to take more risks when you wear a helmet, research also shows overtaking drivers left less room when overtaking a helmeted cyclist (Dr Ian Walker was hit twice while carrying out this research, both times when wearing a helmet). Cyclists also choose to wear helmets for risky situations such as sports cycling or mountain biking.

The much higher injury rate for Dutch cyclists wearing helmets shows they are pretty good judges of the risks.

In countries with helmet laws, the proportion of fatally injured cyclists wearing helmets is almost identical to the population wearing rate, but helmet-wearers are over-represented in the injury statistics. There are two reasons for this: 1) cyclists are more likely to wear helmets for sports and mountain biking where with significant risk of falling off the bike (but low risk of head injury compared to bike/motor vehicle collisions) 2) when cyclists are hit by motor vehicles, non-helmeted are unlikely report the crash because they would be fined, as well as the at-fault motorist.

So it’s a flawed study. As pointed out elsewhere, the odds ratio substantially over-estimates the risk ratio for cyclists who crash or fall off their bikes. And the real risk ratio, comparing cyclists who die of head injury with population helmet-wearing rates suggests the opposite – that cyclists who wear helmets have similar, or higher, fatality rates than non-helmeted cyclists