Board of Science and Education, British Medical Association, November 2004
In response to correspondence from some of its members, the BMA has reconsidered its policy on this issue. Previous policy attached significant emphasis on the BMA's wish not to discourage cycling by making helmets compulsory.
In a referenced paper on its website, BMA cites evidence which purportedly shows that helmet legislation no longer leads to less cycling, and that helmets have proven effective in protecting against head, brain, severe brain and facial injuries, as well as death, as a result of cycling accidents. Accordingly, the BMA have changed its stance to support the introduction of legislation making the wearing of helmets compulsory for both children and adults. The BMA paper also recommends that legislation should be enforced and complemented by educational and promotional campaigns. It adds that other measures, such as cycle training and the creation of a safer cycling environment, should also be pursued.
Changes to BMA paper
The copy of this paper now on the BMA website, to which the above link leads, has been modified since it influenced the change in policy on cycle helmets by the BMA's Board of Science and Education.
In the original document, the following paragraph was included under 'the evidence':
Each year over 50 people aged 15 years and under are killed by cycling accidents, with 70-80 per cent of these resulting from traumatic brain injury .
and additional emphasis appeared in this sentence:
Several recent studies have provided solid scientific evidence that bicycle helmets protect against head, brain, severe brain and facial injuries, as well as death, as a result of cycling accidents.
The comment below is based on the original text.
The BMA paper is not a comprehensive or balanced review of evidence. Its references have been accepted at face value even when the subject of published criticism or contradictory evidence. Some of the facts on which the paper relies are simply wrong.
The BMA states that evidence from Australia that helmet laws discourage cycling is outdated, "and contains distortions from variables including a reduction in the legal age of driving that meant more teenagers travelled in motor vehicles".
The minimum age for a full driving licence has not changed throughout Australia for a long time. However, the minimum age for an accompanied learner driver licence was lowered, from 17 to 16, only in the state of Victoria, where pre-law 16-year olds accounted for 9.9% of cycle traffic (FDRS, 1989). Even if every 16-year old cyclist had changed completely to driving accompanied by an older person, that would account for only a small part of the 43% drop in cycling by Victorian teenagers post-law. It would not account at all for the decline of up to 60% in cycling among teenagers elsewhere in Australia.
Note: The above paragraph has been changed since the first publication of this commentary. It was originally thought that the age for a full driving licence had been lowered in Victoria. However, subsequent enquiries have clarified the fact that the age was lowered only for a provisional learner licence, which requires the learner driver to be accompanied by a full licence holder at all times. This has been confirmed by the Royal Automobile Club of Victoria.
Evidence from Australia indicates that its helmet laws continue to deter cycle use and that in most parts of the country cycling levels are still well below pre-law levels. Where cycling levels have recovered, there has been the loss of more than a decade of cycling growth (cycling levels were generally increasing pre-law), and in some places part of the new increase is due to population growth. Furthermore there have been shifts from regular utility cycling (which yields the greatest health benefits) to leisure cycling, and in the average age of cyclists, with considerably fewer children now riding (WAust, 2004).
In the Australian state of Northern Territory, the mandatory helmet law has been partially repealed, leading to wearing rates of only 15 - 20% today. Yet this state now has the highest proportion of people who cycle in Australia and the lowest ratio of cyclist hospital admissions to population. (ABC, 2004)
In other countries, too, there is clear evidence that helmet laws have a large and long-lasting effect on cycle use. In New Zealand, cycling by schoolchildren remains 40% lower than before the helmet law (LTSA, 2004). In Nova Scotia, Canada, cycle use fell by 40% to 60% following the introduction of a helmet law, with the largest decrease among teenagers (Chipman, 2002).
The BMA's claim that helmet legislation does not reduce the numbers of children cycling is based on a single report (Macpherson, Parkin and To, 2001), and this relates to helmet laws in Ontario, Canada. However, as that same report acknowledges, the helmet law in Ontario was not enforced, which could explain why the number of child cyclists did not reduce (Burdett, 2002). Yet the BMA is seeking strong enforcement of new helmet laws. The Ontario report has also been criticised for its limitations; for example it was based on a small sample size and did not consider cycle use by older children who are the group most likely to give up cycling (Robinson, 2003).
The BMA says that cycle helmet use in Britain is rising, from 16% in 1994 to 25% in 2002, suggesting that it would now be more acceptable to introduce a helmet law. However, these rates only reflect use by adults on main roads. Helmet use by children declined over the same period from 17.5% to 15.2% (16.0% to 12.3% for boys who are 5 times more at risk than girls), indicating that children still have no desire to wear helmets. On minor roads, where most cycling takes place, wearing rates were 10.9% for adults, 6.5% for children in 2002 (Gregory, Inwood and Sexton, 2003).
According to the BMA, each year over 50 people aged 15 years and under are killed by cycling accidents, of whom 70 to 80 per cent die from traumatic brain injury. [Note: this claim has been removed from the current version of the paper but was present in the original presented to the Board of Science and Education]
These statistics are grossly in error. In 2002, 19 children were killed in cycling accidents in England, of whom 10 died as a result of head injuries (Jenkins, 2003). In Scotland the same year, no child cyclist died of head injury (GRO Scotland). Hospital data for England shows that in 2002-3 there were just over 2,000 admissions for head injury to children when cycling. Of these, no more than a few hundred (max 516) were serious injuries with the potential for mitigation by cycle helmets. This is in the context of 6 million children who cycle in England. (Franklin and Chapman, 2005)
The BMA repeats speculation that there are 90,000 cycling accidents each year on-road, and 100,000 off-road. There is no scientific basis to assert such figures and they are not relevant to the paper. The vast majority of injuries to cyclists do not involve head injury and usually amount to no more than cuts or bruises.
The BMA claims that studies in countries with helmet laws have shown that the resulting high rates of helmet use are associated with a reduction in cyclists' deaths and head injuries.
However, large-population studies have not shown a beneficial link between helmet use and fatalities. The largest ever survey, of over 8 million cases of injury and death to cyclists in the USA over 15 years, concluded that there was no evidence that helmets had reduced head injury or fatality rates (Rodgers, 1988); indeed, it suggested that helmeted riders were more likely to be killed. Other studies from the USA (Kunich, 2002) and Canada (Burdett, Can) based on whole populations have also found no effect on fatalities.
In New South Wales (Australia) in the 3 years following the enactment of its helmet law, 80% of cyclists killed and 80% of those seriously injured had worn helmets. These proportions were almost identical to helmet wearing rates at the time (Robinson, 1996; NSW, 1994; Smith and Milthorpe, 1993). More recent reports from Australia suggest that increases in helmet wearing have had little, if any, positive impact on head injuries (Robinson, 1996; Hendrie, Legge, Rosman and Kirov, 1999). A similar situation has been reported in New Zealand (Robinson, 2001).
Outside the context of helmet laws, increasing helmet use does not appear to have influenced fatal or serious injury trends in Great Britain (BHRF, 1236) or Germany (Möllman, Rieger and Wassmann, 2004). In the USA, helmet use increased from 18% to 50% of cyclists from 1991 to 2001 whilst the absolute number of head injuries went up 10%. Pro-rata cycle use, cyclists in 2001 were more likely to suffer a head injury than a decade earlier (CPSC, 2001).
One paper cited by the BMA (Thompson, Rivara and Thompson, 1996c) has been criticised for presenting insufficient information by which to assess the validity of its methodology (Towner et al, 2002). It was funded by the Snell Foundation, whose income is derived in part from helmet sales, and the benefits predicted are not supported by any large population evidence. The Cochrane Review (Thompson, Rivara and Thompson, 2002-9) was written by the same authors and has been criticised for its lack of impartiality. The reviewers were themselves the authors of four of the seven papers reviewed, these papers representing more than three-quarters of the cyclists studied and their findings dominate the analysis. The papers suggesting the greatest protective effects for helmets have been widely criticised for comparing quite different groups of cyclists. Much of this criticism has been appended to the Review in the form of feedback and contrary evidence, but this seems not to have been taken into account by the BMA.
The BMA cites a New Zealand study (LTSA, 2004) that demonstrated a 19 per cent reduction in head injuries to cyclists following legislation. However, further analysis of the original data for this report has shown that the reduction in head injuries after the law represented the returning to normal of the trend in cyclist injuries that had risen above the preceding trend immediately before the law, when helmet use was rising. Taken across the full pre/post law period, there was no improvement in head injuries to cyclists greater than that enjoyed by the population as a whole (Perry, 2001; Robinson, 2001). The New Zealand Household Travel Survey shows that cycling hours decreased by 34% from 1989 to 1997, or approximately 22% following the helmet law. Hence the drop in cycle use was quite possibly higher than the 19% reduction in head injuries.
Reference to a decrease in head injuries in Victoria, Australia is misleading, as is the source cited. A problem is that other legislation relating to speeding and drink-driving was introduced around the same time as the state's helmet law. A consequence of this is that pedestrian fatalities fell by 45% in the year following the laws, although this clearly had nothing to do with the helmet law. Cyclists, too, would have benefited from the other laws, so it is not possible to determine any benefit from the helmet law in isolation. However, the helmet law did result in a fall of 44% in cycling by teenagers and a fall of 29% in cycling by adults, which in itself would account for most of the 40% fall in cyclist head injuries. Some researchers have concluded that cyclists were more likely to suffer head injuries as a result of the helmet law (BHRF, 1239).
The BMA paper argues that, to achieve maximum compliance, legislation should be complemented by mass educational and promotional campaigns. It cites an education programme in Reading (Lee, Mann and Takriti, 2000) that resulted in an increase in helmet use and a concurrent decrease in cycling-related injuries. This paper has been criticised for its poor methodology. Helmet use was judged by self-reporting alone, with no independent verification. The intervention town and the control town (Basingstoke) were quite different in character and the nature of cycling in the two towns would have been different. There was no monitoring of cycle use against which to compare decreases in injuries.
The conclusion of the Reading report was that increased helmet wearing led to a 45% reduction in child cyclists' head injuries. This is quite implausible given that the increase in helmet-wearing rates was only 20 percentage points (from 11% to 31%). Correlation of this report with an earlier report (Lee and Smyth 1996), suggests that at least part of the decrease in head injuries occurred before the increase in helmet wearing. Road casualty data for the Reading area shows no benefit for child cycling casualties; indeed, there is a peak in the (very small) number of serious injuries towards the end of the research period.
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