Citation

Robinson DL. Br. Med. J. BMJ 2006; 332(7543): 722-725.

Affiliation

University of New England, Armidale, NSW 2351, Australia. drobinso@aanet.com.au

Copyright

(Copyright © 2006, BMJ Publishing Group)

DOI

10.1136/bmj.332.7543.722-a

PMID

16565131

PMCID

PMC1410838

Abstract

The author reviews existing research and performs a reanalysis of some of the data. She also cites the evidence from her

review of data from all jurisdictions that have introduced legislation and increased use of helmets by at least 40 percentage points within a few months: New Zealand, Nova Scotia (Canada), and the Australian states of Victoria, New South Wales, South Australia, and Western Australia. To avoid confusing reductions in injuries (from safer roads or less cycling) with benefits of helmets, she focused on percentages of cyclists with head injuries. Head injuries were most commonly classified as admissions to hospital with head wounds, skull or facial fracture, concussion, or other intracranial injury. The data include 10 504 head injuries, and in most cases were available as percentages of all cyclist injuries.

Helmet wearing and head injuries

In contrast to the fall in all road injuries in South Australia coinciding with helmet legislation, percentages of cyclists with concussion and other head or face injuries show generally declining trends, especially for concussion, but no clear response when helmet wearing increased substantially. Falls in concussions were also noted for other road users.

In Western Australia, helmet wearing was negligible before 1980, increasing to about 37% just before the law was introduced, when it rose to 82%.7 As in South Australia, the trend in head injuries among cyclists is similar to that for other road users. This trend of reduced injuries seems to be widespread—for example, almost identical trends for cyclists and pedestrians were seen in the United Kingdom8 and Victoria. Early analyses created considerable confusion by ignoring these trends, mistakenly assuming increased helmet wearing was the only possible cause of the reduction in head injuries.

In New Zealand, most primary school children were already wearing helmets before the law, but helmet wearing among adults increased from 43% to 92% after the law was enacted. If helmet laws were effective, the percentage of adults with head injuries should have fallen substantially more than the percentage of primary school children, but it did not.

Studies were cited to indicate a reduction in the number of cyclists after the laws were passed.

The author concludes that 1) mandatory helmet laws are counterproductive in that they discourage people from riding bicycles and may increase car use; 2) flawed methodologies are responsible study findings that helmets reduce the occurrence of serious head injuries; 3) misinterpretation of findings of other studies led to assumptions about helmet effectiveness and errors in policy-making; 4) injuries to cyclists follow a clear safety in numbers relation -- injury rates per cyclist are lower when more people cycle; and 5) data for cyclists in collisions with motor vehicles show helmet laws increased the risk of death or serious head injury relative to the risk for pedestrians and the amount of cycling. Thus, helmet laws are counterproductive.

Collisions with motor vehicles cause nearly all deaths and debilitating head injuries among cyclists. The large benefits from the road safety campaigns should be contrasted with the lack of obvious effect on head injuries from helmet laws. Yet helmet laws were far more expensive. All published cost-benefit analyses of injury rates before and after helmet laws show the cost of helmets exceeded any estimated savings in healthcare costs.