A new study claims that making cycle helmets compulsory would have a detrimental effect on a country’s overall health.
The report by Piet de Jong, a mathematician at MacquarieUniversity in Sydney, Australia, accepts there would be financial and health gains from fewer head injuries.
But it says these would be tiny in comparison with the costs and the effects on health of the associated drop in cycling.
The professor of actuarial studies estimates that bicycle helmet laws would cost the US $4.8 billion (£3.2bn) per year, the Netherlands $1.9bn (£1.2bn) and the UK $0.4bn (£0.3bn).
The results have proved contentious because they are based on projected figures. De Jong himself admits: “There’s a lot of uncertainty around it. I try to reconcile all these various numbers or proportions that impinge on the question of whether helmet laws are very useful.”
The professor says that in order for mandatory helmet laws to be beneficial for a nation’s healthcare system, head injuries must be a substantial proportion of cycling injuries, few riders must abandon their bikes due to helmet laws, and the health benefits of cycling need to be low.
“Even under very favourable assumptions to the pro-helmet lobby group, it’s very hard to get a benefit,” he concludes.
Previous studies have tended to concentrate on particular consequences of compulsory helmet wearing, often concluding in favour of the ‘pro-helmet’ lobby. For example, a 1989 case-controlled study (i.e. directly comparing helmet wearers with non-helmet wearers) published in the New England Journal of Medicine concluded that bicycle helmets reduce the risk of head injury by 85 per cent.
Writing in the British Medical Journal in 2006, Dorothy Robinson, a statistician at the Department of Primary Industries in Armidale, Australia, claimed that helmet laws caused cycling levels to drop by 20 to 40 percent in several Australian cities and states.
Robinson’s point seems to have been backed up by evidence from 1990 – Victoria, Australia, introduced an all-ages cycle helmet law in that year and helmet use rose from 31 percent to 75 percent, with the number of head injuries dropping by 40 percent.
However, cycle counts in Melbourne showed drops of between 33 percent and 46 percent. Injuries dropped roughly in proportion to the decline in cycling. The proportion of serious head injuries compared to overall injuries fell only slightly.
De Jong believes the 1989 study was overstated, and says: “Everybody takes one piece of the evidence and nobody is really putting in all the pieces of the puzzle.”
However, Barry Pless, a director at Montreal Children’s Hospital with a special interest in research on child injury prevention, says de Jong’s model overvalues the health benefits of recreational cycling.
He says most riders travel short distances rather slowly, blunting some of cycling’s cardiovascular benefits. Pless cites a study of 9,000 UK government employees which found that people between the ages of 45 and 64 needed to pedal 40km per week to see any reduction in heart disease rates.
De Jong, originally from the Netherlands, makes it clear that he would not discourage people from wearing helmets but that people should be able to choose, given the circumstances they cycle under. “I go to Holland and places like that, and I don’t wear a helmet,” he says. “I used to live in London, and I wore a helmet all the time.”