If you know of other research, please contact John Franklin.
References are listed by order of date, then title.
Summaries of papers marked * are based on third-party information and have not been verified by John Franklin, who is also not responsible for the content of links to third-party sources provided for reference.
Dorsch et al. Accident Analysis and Prevention Vol 19:3 pp183-90, 1987.
Predicts 90% saving in fatalities through use of hard-shell helmets.
Rodgers. Journal of Product Liability 11 pp307-17, 1988
To examine claims that growth in the use of hard shell cycle helmets had been successful in reducing cycle-related injuries and death, Rodgers studied over 8 million cases of injury and death to cyclists in the USA over 15 years. He concluded: "There is no evidence that hard shell helmets have reduced the head injury and fatality rates. The most surprising finding is that the bicycle-related fatality rate is positively and significantly correlated with increased helmet use".
Thompson RS, Rivara, Thompson DC. The New England Journal of Medicine Vol 320:21 pp1361-7, 1989.
A study conducted at five hospitals in Seattle between December 1986 and
December 1987 of cyclists admitted to an emergency room. Of 776 cyclists
admitted, 269 had head injuries. 235 of these, and 433 of the 507 cyclists who
were admitted without head injuries, completed a questionnaire. The study
concluded that cycle helmets reduce the risk of head injury by 85% and of brain
injury by 88%. [j264]
Criticisms
of this paper
Wasserman et al. American Journal of Sports Medicine Vol 18:1 pp 96-7, 1990.
Predicts helmets would reduce concussions by 29%, skull fractures by 82%.
Land Safety Transport Authority, New Zealand. 3 reports: 1989, 1990, 1991.
Referenced
from: The cost-effectiveness of compulsory bicycle
helmets in New Zealand.
Of 42 cyclists over 3 years not wearing helmets who were killed (all causes, not just head injuries), 6 may have survived if they had been wearing a helmet. For 21 of the cyclists a helmet would probably have made no difference.
Spaite et al. Journal of Trauma Vol 31:11 pp1510-6, 1991.
Helmet non-use in this study is strongly associated with severe injuries. However, this is true even when cyclists without major head injuries are analysed as a group. The implication is that people who do not use helmets tend to be in higher impact collisions that helmet users, since the injuries suffered in body areas other than the head also tend to be more severe.
Cameron, Heiman, Neiger. Monash University Accident Research Centre Report
32, 1992.
Abstract
available on-line
see: Evaluation of the bicycle helmet wearing law in Victoria during its furst four years.
Hillman. Policy Studies Institute ISBN 0 85374 602 8, 1993
Contents and short summary
available on-line
32-page analysis of pros and cons of cycle helmets with extensive references. Wearing a helmet only marginally reduces the extent of head injury following collision with a motor vehicle, but can affect behaviour so that wearers cycle less cautiously. Mandatory helmets would reinforce public perceptions that cycling is dangerous and encourage the view that cyclists are responsible for their own injury. Life years gained through cycling outweigh life years lost in cycling fatalities by a factor of 20:1. Encouraging helmets leads to fewer people cycling and a net health loss. [j511]
Finch, Newstead, Cameron, Vulcan. Monash University Accident Research Centre Report 51, 1993.
see: Evaluation of the bicycle helmet wearing law in Victoria during its furst four years.
McDermott et al. Journal of Trauma Vol 11:6 pp834-45, 1993.
Study copying techniques of Thompson 1989 research but yielding less favourable results. Own data suggests helmets give 25% reduction in risk of head injury for adults, but no reduction for serious injuries. Adjusting Thompson results to eliminate forehead lacerations, re-calculated benefit is 61% (instead of 85%). Also noted small sample size in Thompson data.
Newstead, Cameron, Gantzer, Finch. Monash University Accident Research
Centre Report 75, 1994.
Abstract
available on-line
see: Evaluation of the bicycle helmet wearing law in Victoria during its furst four years
Thomas et al. British Medical Journal Vol 308 pp173-6, 1994.
Potential of 63% reduction in all head injuries to children under 14 years.
Maimaris, Summers, Browning, Palmer. British Medical Journal Vol 308 pp 1537-40, 1994.
One-year (1992) study at Addenbrooke's hospital based on 1,040 cycle casualties, 114 of whom had worn helmets. No difference between helmet wearers and non-wearers with respect to type of accident and nature of non-head injuries. Head injury sustained by 4% of helmet wearers against 11% of non-wearers. 18% of accidents with motor vehicles involved head injury; 7% when no motor vehicle involved. Deduced increased risk factor of 2.95 if motor vehicle involved, and 3.25 protection factor for wearing a helmet. Advocates compulsory use of helmets. [j986]
Carr, Skalova, Cameron. Monash University Accident Research Centre Report
76, 1995.
Abstract
available on-line
Together with Evaluation of the bicycle helmet wearing law in Victoria during its first 12 months, Head injury reductions in Victoria two years after introduction of mandatory bicycle helmet use, and Bicyclist head injuries in Victoria three years after the introduction of mandatry helmet use, comprises a year-on-year evaluation of head injuries following the introduction of the Victoria helmet law.
Hospital data did not show relationship between helmet wearing and head injury in immediate pre-law years for crashes not involving a motor vehicle. However, head injury rates for cyclists in these crashes were significantly lower post-law. A significant inverse relationship between helmet use and head injury was found for cyclists involved in crashes with motor vehicles. Accident claims showed head injury rates significantly below pre-law predictions in second post-law year, but benefit appeared to have been lost in third year. Hospital records failed to show any additional benefit of law over pre-law trends in the 3 post-law years.
1995 report found biases in injury data used in previous reports, affecting analysis and results, and suggested that hospital admissions for head injury in first 4 years was 40% below pre-law trends and that severity of injuries had declined.
Report abstracts make no reference to trends in the number of people cycling or relative risk.
Hansen, Scuffham. Australian Journal of Public Health Vol 19:5 pp450-4, 1995
Efficacy of helmets in protecting cyclists in New Zealand may be considerably less than predicted by other studies.Cost of helmets per life saved varies from $88,379 for primary school children to $1,014,850 for adults. By comparison, avoided hospital costs range from $3,304 to $56,035. [j984]
Henderson. Motor Accidents Authority of New South Wales, 1995.
Bicycle helmets substantially reduce risk of head injury in a crash.
Cyclists deaths in Australia have fallen by one half in ten years, most in the
years since 1989 (mandatory helmet laws were introduced 1990 to 1992). In
Victoria head injuries decreased 48% and 70% in two years after law. In
Queensland cyclist head injuries fell by more than half following the law,
whilst other bicycle-related injuries remained the same. Old-style (not
Standards approved) helmets ineffective. All helmets less effective if wrongly
placed or without straps tightened. [j997]
Criticisms
of this paper
Pedder. Injury Prevention Vol 2:4 pp250-251, 1996
Helmets must be fitted and worn properly to be fully effective. Even if used properly, a helmet certified to a recognised standard has limited protective capabilities. The design of current helmets reflects the minimum performance requirements of helmet standards, so that it is often inadequate in several respects. Modern helmets protect too small an area of the head. They are not tested for the ability to reduce rotational acceleration. They sometimes fail to provide optimal protection against the more common lesser impacts because they are tested only against severe impacts. Straps and buckles are often not strong enough. Shapes are designed for the heads of adults, not children. Mandatory helmet legislation should only be with reference to adequate helmet standards. [j1002s]
Robinson D. Paper presented at Velo Australis, 1996.
Full paper available
on-line [j987]
Similar content to author's Head injuries and bicycle helmet laws.
Unwin. Journal of Medical Ethics Vol22 pp41-5, 1996.
Aim of paper is not to argue for or against compulsory helmets, but to suggest criteria on which the debate should focus. Author provides four criteria that should be met before legislation:
Thompson DC, Rivara, Thompson RS. 1996
Full paper available on-line
Summary report of the Harborview Helmet Studies.
Study at 7 Seattle
hospitals involving 3,390 cyclists who were injured or died 1992-4. Individuals
with head or brain injuries compared to those involved in crashes but who did
not suffere such injuries. 50.6% had worn helmets at time of crash. Concluded
that helmets decrease risk of head injury by 69%, brain injury by 65% and severe
brain injury by 74%. Helmets work equally well for all age groups, and in
crashes with and without motor vehicles (which are most important risk factor
for serious injury). Substantial protection provided against lacerations and
fractures to upper and mid-face, but not to lower face. Hard shell helmets may
offer greatest protection against severe brain injury. [j977]
Robinson DL. Accident Analysis and Prevention Vol 28 No 4 pp463-75, 1996.
Abstract available
on-line
Review of mandatory helmet laws in Australia. Greatest effect of law was to discourage cycling. Increase to at least 75% helmet wearing resulted in decline of only 13% in head injuries, less than decline in cycling. Reduction in head injuries very similar for pedestrians, and possibly due more to speed and drink-driving initiatives than helmets. Helmets for motor vehicle occupants have potential to save 17 times as many deaths as cyclists, without adverse effects of discouraging a heathy mode of transport. [j982]
Bruce Robinson, Bicycle Federation of Australia. Velo Australis conference,
1996.
Full paper
available on-line
The author is a long-time advocate of cycle helmets and did not oppose Australian legislation. The evidence so far indicates that our initial belief in the effectiveness of the legislation may well have been ill-founded, and our hopes for road safety and equity improvements as a result of the Federal funding package naive. So far there is no convincing evidence that Australian helmet legislation has reduced the risk of head injury in bicycle crashes. It is not clear why the legislation has not been more effective. [j993]
Kennedy. British Journal of Sports Medicine Vol 30 pp130-3, 1996.
Examination of 28 cyclists deaths over 15 years in Sheffield and Barnsley. Over 80% of both cases and controls had severe head injuries, but controls (an equal number of pedestrians and motor vehicle occupant fatalities) suffered more fatal injuries to other parts of the body. If helmets had saved all those who only had head injuries, at best 14 (50%) of cyclist deaths would have been prevented. On the other hand, if pedestrians and vehicle occupants had worn helmets, 175 lives may have been saved in the same period. No justification for compelling cyclists to wear helmets without taking steps to improve safety of all road users. [j983]
Scuffham, Langley. Accident Analysis and Prevention, Vol 29:1, 1997
Abstract
available on-line
An ecological analysis of serious head and non-head injuries to cyclists, and helmet wearing survey data, 1989 to 1992 (prior to introduction of NZ manadatory helmet law). Helmet wearing rates increased over period from 46% to 84% for primary schoolchildren, 23% to 62% for secondary schoolchildren, and 21% to 39% for adults. All serious injuries to cyclists decreased substantially for children, but not for adults. Serious head injuries as a percentage of all serious injuries remained constant for all groups, with no apparent difference between bicycle-only and motor vehicle related crashes. However, percentages of mild concussions and lacerations to the scalp decreased more than other cyclist head injuries. The failure to achieve the expected decline in serious head injury could be attributable to a variety of factors, including the incorrect fitting and wearing of the helmet. Cycle use declined over the study period by 19%. [j985s]
Which?, journal of The Consumers' Association, pp 28 - 31, October 1998.
Performance tests of cycle helmets, all produced to meet international standards. 14 of the 24 helmets failed the test criteria for shock absorption, and two of the remainder failed tests related to retention and strap strength. Only two of the 24 helmets met the more demanding Snell standard, and one of those caused some impairment of a cyclist's vision. [j980]
Robinson. Injury Prevention, pp 170-172, September 1998.
Also Australian
Doctor, 27 February 1998.
Available on line
Uses data from Australia to suggest that cycle helmet laws have done more harm than good. They have not produced any noticeable reduction in head injury rates. However, by discouraging cycling, they have deprived many of healthy exercise and pollution-free transport. [j1023]
McLean et al, Federal Office of Road Safety Australia, Report CR160, 1998
Summary on
line
Head injuries to car occupants are a major cause of death and permanent brain damage. Evaluates benefits for motorists of interior padding and the use of headwear, such as a soft shell bicycle helmet. It is concluded that helmets would offer by far the best form of protection, with or without car air bags. Total benefits are estimated to be AUD380 million, compared with AUD123 million for car padding.
Kunich, 1998
Available
on line
Comments on shortcomings of helmet standards, and analyses US cyclist and pedestrian fatalities from 1986 to 1996. During this period cycle helmet use grew from close to zero to 30% or more. There is no reflection of this in the fatality statistics; indeed cyclist deaths have declined less rapidly than those of pedestrians. [j979]
Burdett, 1999
Available
on line
Fatality trends have been similar for cyclists and pedestrians over 22 years of study; both have fallen. Although helmet use grew from virtually zero in 1988 to over 30% in 1995 and up to 50% in 1997, there is no detectable change in the fatality trends attributable to this. Programs aimed at motorists have been effective at reducing fatalities to all road users, including pedestrians and cyclists. Measures are needed to improve cyclists' skills and to increase use of lights by cyclists at night. [j994]
Hendrie, Legge, Rosman & Kirov, Road Accident Prevention Research Unit,
WA, 1999
Available on line
Acknowledges criticisms of earlier studies of effectiveness of helmet legislation. Makes new assessment of head injury reduction by two methods, taking into account trends affecting all road users. These give absolute reductions in head injuries of 20% and 11% respectively, less than the decrease in cycle use. Also assesses cost effectiveness of the legislation. Depending upon assumed level of injury reduction, cost benefit is +$AUS 2m to - $AUS 10.6m. Many costs excluded, included those associated with reduced cycling activity.[j]
Report by the Board of Science and Education, British Medical Association,
June 1999.
ISBN 0 7279 1430 8
Looks at cycling crashes and injuries in the UK; cycle helmet design, standards and benefits; health benefits of cycling; international evidence from countries where cycle helmets are compulsory; and makes recommendations for BMA policy.
The report recognises the limitations of helmets and research, and the negative health effects of discouraging people from cycling through helmet promotion. It would be of concern to the BMA if people stopped cycling or transferred more to cars. Notes that helmet legislation would only cover on-highway cycling where helmet benefits are least, and not off-road where they may have a more useful role to play.
Recommends against the compulsory use of helmets and in favour of promotion. Helmets should be only one part of a much broader strategy to promote cycling.
Ministerio del Interior, Spain, March 1999
PDF
file
Spanish Government investigation of non-fatal cycle accidents on road, which concludes that no advantages of helmet wearing have been found in the data set.
Franklin, 2000
Available on line
Examines cyclist casualties in Britain as a whole, Greater London and Cambridge, over the period when helmet use has risen from virtually zero to over 40 per cent of cyclists in some parts of the country. There is no detectable change in trends for fatalities, serious injuries or severity ratio in any of these data sets to match the increase in use of cycle helmets. Indeed, in some cases the average seriousness of cyclist casualties increased duirng the period of greatest helmet take-up.
The paper also looks at findings from research in the USA, Canada, Australia and New Zealand that have also failed to find real-world evidence of any significant reduction in cyclist head injuries in large population samples. [j]
Thompson DC, Rivara, Thompson R, The Cochrane Library, issue 3, 2000, Oxford.
Analysis of five studies into head injury (including two by the review authors) and three into facial injury (including two by review authors), considered to be best to meet selection criteria. Considers these provide clear evidence that helmets reduce head and facial injuries for cyclists of all ages in all types of crashes.
Scuffham, Alsop, Cryer & Langley, University of Otago, 2000
Examined injuries to three age groups of cyclists admitted to hospitals in New Zealand between 1988 and 1996. Results indicate a positive effect of helmet wearing on head injury, which was relatively consistent acorss age groups and injury types. Admits results inconsistent with research by Scuffham and Langley in 1997 but offers no clear explanation for this.
Cook, Sheikh, BMJ 28th October 2000
Available on line
For 4 years from 1 April 1991, using NHS records of emergency admissions, calculated number of cyclists admitted with head injuries as percentage of total number of cyclists admitted, subdivided into 3 age ranges. Total emergency admissions changed little over period, but number with head injuries fell from 3393 to 2571. As helmet use had risen over this period, concludes that decrease in head injuries due to increased helmet use.
This article has been much criticised for being over-simplistic and not considering any other possible influences or long-term trends. Calculation in results in error by a factor of 10. Many criticisms are referenced from the article on the BMJ website.
Attewell, Glase & McFadden, Accident Analysis and Prevention, 2001 pp 345-352
Analysis of peer-reviewed studies which include individual injury and helmet use data, published 1987-98. Overall risk reduction 45% for head injury, 33% for brain injury, 27% for facial injury, 29% for fatal injury. Some evidence of increased neck injury. Authors plead for greater acceptance of helmet use.
Comment: Most studies used have very small samples, sometimes only 3 to 10 injured cyclists. Largest sample is 757.
Barnes, 2001
Report in New York Times,
29th July 2001
According to data from the US Consumer Product Safety Commission, the number of head injuries to cyclists has increased 10 per cent since 1991 despite a sharp rise in cycle helmet use. But ridership over the same period has declined, so that the rate of head injuries per active cyclist over the decade has increased 51 per cent.
Experts are mystified as to why injuries are on the rise. According to CPSC assistant executive director Ronald L. Medford, "It's puzzling to me that we can't find the benefit of bike helmets here".
The article floats several possible reasons for the discrepancy, such as an increase in aggressive driving, the improper wearing of helmets and a shift to off-road riding, but emphasises most the possibility of risk compensation. Almost no-one, says the article, suggests that cyclists should stop wearing helmets, accepting the unsubstantiated Thompson, Rivara & Thompson statistic that helmets reduce the severity of brain injuries by 88 per cent.
LeBlanc, Beattie, Culligan. Canadian Medical Association Journal, 5th March 2002.
Also: Hats off (or not?) to helmet legislation
Chipman.
In same issue of Journal.
Main article on-line
Supplementary article.
In 1997 legislation made the use of helmets mandatory for cyclists in Nova Scotia. In 3 years the proportion of cyclists wearing helmets rose from 36% to 86% and the proportion of head injuries to cyclists halved. However, there was also a drop of 40% to 60% in the number of people who cycle, with the greatest decrease amongst adolescents. In the context of reduced cycle use, those who continue to cycle but now wear helmets are no less likely to suffer a head injury than before. The number of head injuries has fallen only in line with cycle use.
However, the number of non-head injuries to cyclists over the 3 years increased by 6% in absolute terms. Relative to cycle use, those who continue to cycle are now 87% more likely to suffer injury than prior to helmet legislation.