Based on a letter published in the Medical Journal of Australia, 5 May 1997 (V166; p510)
Acton, Nixon and Clark, 1996 state that since legislation on bicycle helmets was introduced in Queensland, the risk of head and brain injury in those who wear bicycle helmets has been reduced. This statement is only partially supported by data from the Queensland Road Crash Database (Road Transport and Safety Division, Queensland Transport). The percentage of skull fractures and head wounds show some relationship with helmet wearing (which increased with the introduction of the legislation in July 1991 and its enforcement in January 1993) (King and Fraine, 1993), but the total proportion suffering brain injury/concussion remains unchanged (Box). From 1993-1995, the rate of intracranial injuries was little different and there were more cyclists with concussions than in 1991 when only half the number were wearing helmets. The rates of concussions and other intracranial injuries were both higher in 1992 when half wore helmets than in 1990 when perhaps a quarter wore helmets.
There is a lack of convincing evidence of reductions in brain injury following helmet laws. In New Zealand, "increased helmet wearing has had little association with serious head injuries to cyclists as a percentage of all serious injuries to cyclists" (Scuffham and Langley, 1997). In Victoria, the proportion cyclists with head injuries in the third year after the introduction of the helmet law was no different from the trend predicted by the model using pre-law wearing rate trends (Finch, Heiman and Neiger, 1993). In Western Australia, the proportions of hospitalised cyclists with head injuries followed almost identical trends to those for pedestrians, car drivers and car passengers, with no noticeable effect of a law which increased helmet wearing from under 40% to more than 80% of all cyclists (D Hendrie, Research Officer, Roadwatch, University of Western Australia, personal communication).
The decline in non-head injuries in 1993 (with enforcement of the law) probably reflects a decline in cycling. Comparable pre-and post-law surveys in Queensland and adults in NSW are lacking, but declines of 36% were observed in counts of all cyclists in Victoria (Finch, Heiman and Neiger, 1993) and child cyclists in NSW (Walker, 1992). The BMA reported "Car travel is more deleterious to health unless the motorist can exercise several times a week by other means that will maintain fitness" (BMA, 1992). It would be interesting to see a cost-benefit analysis contrasting the loss of healthy exercise/pollution-free transport with these relatively small and somewhat inconclusive effects on head injuries.
Acton CH, Nixon JS, Clark RC, 1996. Bicycle helmet legislation and oral/maxillofacial trauma in young children. Med J Aust 1996:249-251.
Cycling towards health and safety. British Medical Association ISBN 0-19-286151-4.1992.
Finch C, Heiman L, Neiger D, 1993. Bicycle Use and Helmet Wearing Rates in Melbourne, 1987 to 1992: the influence of the helmet wearing law. Monash University Accident Research Centre Report 45.
King M, Fraine G, 1993. Bicycle helmet legislation and enforcement in Queensland 1991-3: effects on helmet wearing and crashes. Queensland Transport, Brisbane June 1993.
Scuffham PA, Langley JD, 1997. Trends in cycle injury in New Zealand under voluntary helmet use. Accident Analysis and Prevention 1997 Jan;29(1):1-9.
Walker MB, 1992. Law compliance among cyclists in NSW (3rd survey). Road Traffic Authority NSW .