The impact of compulsory cycle helmet legislation on cyclist head injuries in New South Wales, Australia

ArticleinAccident; analysis and prevention 43(6):2064-71 · November 2011with 159 Reads
Abstract
The study aimed to assess the effect of compulsory cycle helmet legislation on cyclist head injuries given the ongoing debate in Australia as to the efficacy of this measure at a population level. We used hospital admissions data from New South Wales, Australia, from a 36 month period centred at the time legislation came into effect. Negative binomial regression of hospital admission counts of head and limb injuries to cyclists were performed to identify differential changes in head and limb injury rates at the time of legislation. Interaction terms were included to allow different trends between injury types and pre- and post-law time periods. To avoid the issue of lack of cyclist exposure data, we assumed equal exposures between head and limb injuries which allowed an arbitrary proxy exposure to be used in the model. As a comparison, analyses were also performed for pedestrian data to identify which of the observed effects were specific to cyclists. In general, the models identified a decreasing trend in injury rates prior to legislation, an increasing trend thereafter and a drop in rates at the time legislation was enacted, all of which were thought to represent background effects in transport safety. Head injury rates decreased significantly more than limb injury rates at the time of legislation among cyclists but not among pedestrians. This additional benefit was attributed to compulsory helmet legislation. Despite numerous data limitations, we identified evidence of a positive effect of compulsory cycle helmet legislation on cyclist head injuries at a population level such that repealing the law cannot be justified.
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  • Article
    This paper challenges the conclusion of a recent paper by Walter et al. (Accident Analysis and Prevention 2011, doi:10.1016/j.aap.2011.05.029) reporting that despite numerous data limitations repealing the helmet legislation in Australia could not be justified. This conclusion is not warranted because of the limited time period used in their analysis and the lack of data beyond a few years before the introduction of legislation, the failure to adequately account for the effect of the phasing in of the legislation, the effect of the marked reduction in child cyclists, and the non-comparability of the pedestrian and cycling injuries and related lack of consideration of the severity of head injuries. The extent to which helmet legislation deters people from cycling is discussed.
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  • Conference Paper
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    Road safety interventions directed at a population such as mandatory helmet legislation (MHL) and seat belt laws are often assessed by interrupted time series (ITS) methods. Such interventions are often controversial since the pre- and post-intervention periods are not randomised making causal inference difficult. It is possible for changes in the time series of interest to be due to unmeasured confounders and not the intervention. For example, it is often argued by those opposing MHL that the decline in bicycle related head injuries following this intervention could be due to declines in cycling ridership and not a safety benefit. The inclusion of a comparative series in ITS designs is a potential way to account for unmeasured confounding; however, statistically rigorous criteria for selecting a comparator are yet to be developed. To that end, this paper examines the use of empirical Bayes methods as a means for detecting unmeasured confounding and for choosing the best comparative time series. ITS using empirical Bayes consists of estimating a post-intervention trajectory, or counterfactual, using the pre-intervention data. The trajectory is then compared to the post-intervention data for deviations from the counterfactual. These methods will be applied to NSW hospitalisation data around the mandatory helmet law as a demonstration.
  • Conference Paper
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    Since the introduction of mandatory helmet legislation (MHL) in Australia, debate on the effect of MHL on cyclist head injuries has been ongoing. The debate sometimes revolves around the statistical methodology used to assess intervention effectiveness. Supporters of rescinding the MHL thereby encouraging cyclists to ride without helmets, regularly dismiss statistical evaluations as being flawed for various reasons. In a more general context, researchers want to estimate whether and how a policy intervention changed an outcome of interest. Quasi-experimental interrupted time series (ITS) is the most appropriate design to evaluate the longitudinal effects of policy interventions and segmented regression analysis is often used as a powerful statistical method for ITS. Recent research has employed a log-linear regression model for the hospital admission counts of head and limb injuries from New South Wales, Australia, from a 36 month period centred at the time of legislation. Estimation of the model was done using a frequentist approach. In this paper, we re-analyse this data using empirical Bayes and full Bayesian methods, since the use of these methods has become popular in road safety studies. In particular, we show how a full Bayesian method can be readily implemented in WinBUGS software. We discuss the advantages and disadvantages of each method and describe and compare the different estimation methods in terms of parameter estimates. The results show that all three estimation methods give consistent conclusions regarding the positive effect of compulsory helmet wearing on cyclist head injuries in New South Wales.
  • Conference Paper
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    Bicycle helmets are designed to mitigate head injury during a collision. In the early 1990's, Australia and New Zealand mandated helmet wearing for cyclists in an effort to increase helmet usage. Since that time, helmets and helmet laws have been portrayed as a failure in the peer-reviewed literature, by the media and various advocacy groups. Many of these criticisms claim helmets are ineffective, helmet laws deter cycling, helmet wearing increases the risk of an accident, no evidence helmet laws reduce head injuries at a population level, and helmet laws result in a net health reduction. This paper will demonstrate the data and methods used to support these arguments are statistically flawed.
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  • Article
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    Bicycle helmets are designed to mitigate head injury during a collision. In the early 1990's, Australia and New Zealand mandated helmet wearing for cyclists in an effort to increase helmet usage. Since that time, helmets and helmet laws have been portrayed as a failure in the peer-reviewed literature, by the media and various advocacy groups. Many of these criticisms claim helmets are ineffective, helmet laws deter cycling, helmet wearing increases the risk of an accident, no evidence helmet laws reduce head injuries at a population level, and helmet laws result in a net health reduction. This paper reviews the data and methods used to support these arguments and shows they are statistically flawed. When the majority of evidence against helmets or mandatory helmet legislation (MHL) is carefully scrutinised it appears overstated, misleading or invalid. Moreover, much of the statistical analysis has been conducted by people with known affiliations with anti-helmet or anti-MHL organisations.
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    Background: Mandatory helmet legislation (MHL) for cyclists became effective in New Zealand (NZ) on 1 January 1994. Assessments of the NZ MHL have led to conflicting conclusions regarding its effectiveness at reducing cycling head injury and risk of fatality. These studies also differ in their use of analytic approaches and data sources. Objectives: The aim of this paper is to systematically review all studies that assess the NZ MHL in accordance with quality criteria for assessing population-based interventions. Data Sources: A search of Medline, Scopus and Web of Science for peer-reviewed articles from 1994 to 9 September 2014 was conducted. Study Selection: Documents were independently extracted by two reviewers and limited to original articles in peer reviewed journals that assessed the NZ MHL in terms of cycling head injury. Results: The results from three of the four included studies indicated a positive effect of MHL for increasing helmet wearing and reducing head injuries. However, the findings of these studies must be interpreted within the context of methodological limitations. Conclusion: We believe more high quality evaluations are needed to provide evidence for an objective assessment of MHL in NZ.
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    Objective This study aimed to examine trends in the incidence and outcomes of bicycle-related injuries in emergency departments (ED) in South Korea. Methods We analysed data from the National Emergency Department Information System database for adult patients (≥20 years) with bicycle-related injuries presenting to EDs in South Korea between January 2012 and December 2014. Riders and bicycle passengers whose injuries were associated with bicycle use were included. Serious outcomes were defined as death at the ED, need for emergency operation, or intensive care unit admission. Results The number of people who commute to work by bicycle increased by 36% from 205,100 in 2005 to 279,544 in 2015. Of 529,278 traffic-related trauma cases, 58,352 (11.0%) were bicycle-related, which increased from 7,894 (10.2%) in the first half of 2012 to 12,882 (12.2%) in the second half of 2014 (p < 0.001). However, the proportion of serious outcomes decreased from 5.0% to 4.2% during the study period (p < 0.001). Serious outcomes were most frequent in the elderly (65–74 years) and older elderly (≥75 years) groups and decreased for all but the elderly age group from 10.3% to 9.8% (p = 0.204). The helmet use rate increased from 14.2% to 20.3% (p < 0.001) but was the lowest in the older elderly group (3.6%) without change during the study period (from 4.7% to 3.7%, p = 0.656). A lack of helmet use was significantly associated with serious outcomes (odds ratio, 1.811; 95% confidence interval, 1.576–2.082). Conclusions Although the incidence of bicycle-related injuries increased, the proportion of serious outcomes decreased, possibly due to increased helmet use. Public education on safety equipment use is required, especially in elderly populations.
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    Introduction According to official statistics in Taiwan, the main body region of injury causing bicyclist deaths is the head, and bicyclists are 2.6 times more likely to be fatally injured than motorcyclists. There is currently a national helmet law for motorcyclists but not for bicyclists. Objectives The primary aim of this study was to determine whether bicyclist casualties have higher odds of head-related hospitalisation than motorcyclists. This study also aims to investigate the determinants of head injury-related hospitalisation among bicyclists and motorcyclists. Methods Using linked data from the National Traffic Accident Dataset and the National Health Insurance Research Database for the period 2003–2012, this study investigates the crash characteristics of bicyclist and motorcyclist casualties presenting to hospitals due to motor vehicle crashes. Head injury-related hospitalisation was used as the study outcome for both road users to evaluate whether various factors (eg, human attributes, road and weather conditions, vehicle characteristics) are related to hospital admission of those who sustained serious injuries. Results Among 1 239 474 bicyclist and motorcyclist casualties, the proportion of bicyclists hospitalised for head injuries was higher than that of motorcyclists (10.0% vs 6.5%). However, the multiple logistic regression model shows that, after adjustment of this result for other factors such as helmet use, bicyclists were 18% significantly less likely to be hospitalised for head injuries than motorcyclists (AOR 0.82, 95% CI 0.79 to 0.85). Other important determinants of head injury-related hospitalisation for bicyclists and motorcyclists include female riders, elderly riders, crashes occurring in rural areas, moped riders, riding unhelmeted, intoxicated bicyclists and motorcyclists, unlicensed motorcyclists, dusk and dawn conditions and single-vehicle crashes. Conclusions Our finding underscores the importance of helmet use in reducing hospitalisation due to head injuries among bicyclists while current helmet use is relatively low.
  • Article
    Evidence for the effectiveness of cycle helmets has relied either on simplified experiments or complex statistical analysis of patient cohorts or populations. This study directly assesses the effectiveness of cycle helmets over a range of accident scenarios, from basic loss of control to vehicle impact, using computational modelling. Simulations were performed using dynamics modelling software (MADYMO) and models of a 50% Hybrid III dummy, a hybrid cross bicycle and a car. Loss of control was simulated by a sudden turn of the handlebars and striking a curb, side and rear-on impacts by a car were also simulated. Simulations were run over a representative range of cycle speeds (2.0-14.0ms(-1)) and vehicle speeds (4.5-17.9ms(-1)). Bicycle helmets were found to be effective in reducing the severity of head injuries sustained in common accidents. They reduced the risk of an AIS>3 injury, in cases with head impacts, by an average of 40%. In accidents that would cause up to moderate (AIS=2) injuries to a non-helmeted rider, helmets eliminated the risk of injury. Helmets were also found to be effective in preventing fatal head injuries in some instances. The effectiveness of helmets was demonstrated over the entire range of cycle speeds studied, up to and including 14ms(-1). There was no evidence that helmet wearing increased the risk of neck injury, indeed helmets were found to be protective of neck injuries in many cases. Similarly, helmets were found to offer an increase in protection even when an increase in cycle speed due to risk compensation was taken into consideration.
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    Objective To investigate the association between helmet legislation and admissions to hospital for cycling related head injuries among young people and adults in Canada. Design Interrupted time series analysis using data from the National Trauma Registry Minimum Data Set. Setting Canadian provinces and territories; between 1994 and 2003, six of 10 provinces implemented helmet legislation. Participants All admissions (n=66 716) to acute care hospitals in Canada owing to cycling related injury between 1994 and 2008. Main outcome measure Rate of admissions to hospital for cycling related head injuries before and after the implementation of provincial helmet legislation. Results Between 1994 and 2008, 66 716 hospital admissions were for cycling related injuries in Canada. Between 1994 and 2003, the rate of head injuries among young people decreased by 54.0% (95% confidence interval 48.2% to 59.8%) in provinces with helmet legislation compared with 33.1% (23.3% to 42.9%) in provinces and territories without legislation. Among adults, the rate of head injuries decreased by 26.0% (16.0% to 36.3%) in provinces with legislation but remained constant in provinces and territories without legislation. After taking baseline trends into consideration, however, we were unable to detect an independent effect of legislation on the rate of hospital admissions for cycling related head injuries. Conclusions Reductions in the rates of admissions to hospital for cycling related head injuries were greater in provinces with helmet legislation, but injury rates were already decreasing before the implementation of legislation and the rate of decline was not appreciably altered on introduction of legislation. While helmets reduce the risk of head injuries and we encourage their use, in the Canadian context of existing safety campaigns, improvements to the cycling infrastructure, and the passive uptake of helmets, the incremental contribution of provincial helmet legislation to reduce hospital admissions for head injuries seems to have been minimal.
  • Article
    Head injuries are a significant cause of death and injury to child cyclists both on and off the road. Current evaluations of the effectiveness of cycle helmets rely on simplified mechanical testing or the analysis of aggregated accident statistics. This paper presents a direct evaluation of helmet efficacy by using computational modelling to simulate a range of realistic accident scenarios, including loss of control, collision with static objects and vehicle impact. A 6-year-old cyclist was modelled (as a Hybrid III 6-year-old dummy), in addition to a typical children's bicycle and a vehicle using the MADYMO dynamics software package. Simulations were performed using ranges of cyclist position, cycle speed and vehicle speed with and without a helmet that meets current standards. Wearing a cycle helmet was found to reduce the probability of head injuries, reducing the average probability of fatality over the scenarios studied from 40% to 0.3%. Similarly, helmet wearing reduced the probability of neck injuries (average probability of fatality reduced from 11% to 1%). There was no evidence that helmet wearing increased the severity of brain or neck injuries caused by rotational accelerations; in fact these were slightly reduced. Similarly, there was no evidence that increased cycling speed, such as might result from helmet related risk compensation, increased the probability of head injury.
  • Article
    This article responds to criticisms made in a rejoinder (Accident Analysis and Prevention 2012, 45: 107–109) questioning the validity of a study on the impact of mandatory helmet legislation (MHL) for cyclists in New South Wales, Australia. We systematically address the criticisms through clarification of our methods, extension of the original analysis and discussion of new evidence on the population-level effects of MHL. Extensions of our analysis confirm the original conclusions that MHL had a beneficial effect on head injury rates over and above background trends and changes in cycling participation. The ongoing debate around MHL draws attention away from important ways in which both safety and participation can be improved through investment in well-connected cycling infrastructure, fostering consideration between road users, and adequate legal protection for vulnerable road users. These are the essential ele-ments for providing a cycling environment that encourages participation, with all its health, economic and environmental benefits, while maximising safety.
  • Article
    There has been an ongoing debate in Australia and internationally regarding the effectiveness of bicycle helmets in preventing head injury. This study aims to examine the effectiveness of bicycle helmets in preventing head injury amongst cyclists in crashes involving motor vehicles, and to assess the impact of 'risky cycling behaviour' among helmeted and unhelmeted cyclists. This analysis involved a retrospective, case-control study using linked police-reported road crash, hospital admission and mortality data in New South Wales (NSW), Australia during 2001-2009. The study population was cyclist casualties who were involved in a collision with a motor vehicle. Cases were those that sustained a head injury and were admitted to hospital. Controls were those admitted to hospital who did not sustain a head injury, or those not admitted to hospital. Standard multiple variable logistic regression modelling was conducted, with multinomial outcomes of injury severity. There were 6745 cyclist collisions with motor vehicles where helmet use was known. Helmet use was associated with reduced risk of head injury in bicycle collisions with motor vehicles of up to 74%, and the more severe the injury considered, the greater the reduction. This was also found to be true for particular head injuries such as skull fractures, intracranial injury and open head wounds. Around one half of children and adolescents less than 19 years were not wearing a helmet, an issue that needs to be addressed in light of the demonstrated effectiveness of helmets. Non-helmeted cyclists were more likely to display risky riding behaviour, however, were less likely to cycle in risky areas; the net result of which was that they were more likely to be involved in more severe crashes.
  • Aim Injuries involving non‐motorised wheeled recreational vehicles (NMWRV) and bicycles are a common cause for hospitalisation in children. Studies show that helmet use whilst bicycle riding can decrease mortality and morbidity due to head injury. However, there remains an important proportion of children who are non‐helmet users (NHU). This study aims to investigate helmet use and attitudes and injury patterns in children presenting with trauma after riding bicycles and other NMWRVs. Methods A prospective cohort study was undertaken over 8 months of children aged 0–16 years, who presented with injury secondary to bicycle or NMWRV to the emergency department of two tertiary paediatric centres. Demographics, incident, injury severity and attitudes towards helmet use were compared between helmet users and NHU. Results A total of 342 children were included – 41% (n = 139) scooter riders, 39% (n = 133) bicyclists, 18% (n = 61) skateboarders and 2% (n = 9) in‐line skaters. Of those interviewed (n = 161), 58% (n = 93) wore a helmet, with children riding bicycles significantly more likely to be helmeted than NMWRV (75 vs. 48%, P = 0.01). NHU were more likely to be admitted to hospital (P = 0.05) and to sustain a major head injury (P = 0.009). The main influence on helmet use was parental rules. The biggest factor influencing non‐helmet use was perceived low levels of danger. Conclusions Despite legislation mandating this, helmet use is not universal in cyclists, particularly younger riders. Even fewer NMWRV riders use them. To promote helmet use, a multifaceted approach aimed at altering community norms and individual behaviours and attitudes is required.
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    Full-text available
    Rissel and Wen?s article boldly proclaims that repealing mandatory helmet legislation (MHL) would greatly increase cycling uptake. However, closer examination of their results reveals that odds ratios are interpreted incorrectly several times and some findings were curiously omitted. They state that people 'aged 16-24 years...were significantly more likely to ride more if they did not have to wear a helmet'. This is only found to be true when compared to those aged 55+ but is not shown to be the case compared to the broader adult population. If the intent is to state those aged 16-24 years are significantly more likely than not to cycle more, this is clearly not true as significantly more people responded to the contrary (0.341, 95%CI: 0.235-0.447). Also, significantly more people in the other age groups responded they would not ride more, with an apparent downward trend in proportion by age.
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  • Conference Paper
    Full-text available
    Mandatory helmet legislation (MHL) was introduced in New Zealand (NZ) in January 1994. Previous studies have shown a significant reduction in cycling head injury associated with MHL; however, one analysis has suggested a diminishing return in head injury reduction with increased helmet wearing rates. The aim of this study is to critically assess the validity of methods and conclusions from studies evaluating the effect of MHL on head injury in NZ. We emphasise the importance of accurately and objectively presenting data and the need for a proper subsequent analysis for valid inference. This plays a paramount role in the communication of research findings as they heavily influence the public perception of road safety and the effectiveness of policy interventions.
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    Full-text available
    The promotion of safe cycling is a way to address physical inactivity, one of the risk factors for non-communicable diseases (NCDs). In the report Road safety in the European Union: Trends, statistics and main challenges (March 2015), 8% of all fatalities are cyclists. Bicycle helmets can reduce the risk of head and brain injuries and death. Most EU Member states have no requirement in legislation for bicycle helmets. Consequences of mandatory helmet legislation include decreases in head injuries and death, decreases cycling as a mode of transport, and increases helmet use. Other considerations, which influence bicycle accidents, need to be considered. In Malta there were three deaths due to cycling between 2006 and 2015. The number of Accident & Emergency (A&E) attendances with cycling related injuries increased between 2009 and 2015. The number of A&E attendances in the 0-19 age group decreased whereas the 20-39 and 40-59 year age groups increased. In 2013, there were 173 registered injuries in cyclists, with head, upper extremity and lower extremity involvement in 28%, 40% and 21% respectively. Recommendations include improving data collection, education campaigns, strong recommendation for helmet use in adults, to consider the introduction of mandatory helmet legislation in children and implementation of infrastructure measures to make roads more cycling friendly.
  • Article
    In 1989, long before this journal added injuries to its title, it published two papers on childhood injuries and I was asked to write an editorial for this occasion. I chose the title "Challenges for Injury Prevention: Two Neglected Aspects" because I thought the papers neglected to mention the inadequacy of injury statistics (at the time there were no emergency department data) and also failed to emphasize the public health importance of childhood injuries. It is instructive, therefore, to compare this issue's offerings with how matters stood nearly 25 years ago and see what progress we've made. Papers in this and the previous issue of this journal discuss bicycle safety in general and helmet use in particular. Although this is a somewhat narrow focus, it serves as one indicator of how the field has evolved and what remains to be done to improve both the science and policy in this domain.
  • Article
    Background Previous population-based research has shown that bicycle helmet laws can reduce head injury rates among cyclists. According to deterrence theory, such laws are mainly effective if there is a high likelihood of being apprehended. In this study, we investigated the effect of the Swedish helmet law for children under the age of 15, a population that cannot be fined. Method An interrupted time series design was used. Monthly inpatient data on injured cyclists from 1998–2012, stratified by age (0–14, 15 +), sex, and injury diagnosis, was obtained from the National Patient Register. The main outcome measure was the proportion of head injury admissions per month. Intervention effect estimates were obtained using generalized autoregressive moving average (GARMA) models. Pre-legislation trend and seasonality was adjusted for, and differences-in-differences estimation was obtained using adults as a non-equivalent control group. Results There was a statistically significant intervention effect among male children, where the proportion of head injuries dropped by 7.8 percentage points. There was no evidence of an intervention effect on the proportion of head injuries among female children. Conclusion According to hospital admission data, the bicycle helmet law appears to have had an effect only on male children. Practical applications This study, while quasi-experimental and thus not strictly generalizable, can contribute to increased knowledge regarding the effects of bicycle helmet laws.
  • Article
    The head is the body region that most frequently incurs fatal and serious injuries of cyclists in collisions against vehicles. Many research studies investigated helmet effectiveness in preventing head injuries using accident data. In this study, the impact attenuation characteristics of three Japanese child bicycle helmets were examined experimentally in impact tests into a concrete surface and a vehicle. A pedestrian adult headform with and without a Japanese child bicycle helmet was dropped onto a concrete surface and then propelled into a vehicle at 35 km/h in various locations such as the bonnet, roof header, windshield and A-pillar. Accelerations were measured and head injury criterion (HIC) calculated. In the drop tests using the adult headform onto a concrete surface from the height of 1.5 m, the HIC for a headform without a child helmet was 6325, and was reduced by around 80% when a child helmet was fitted to the headform. In the impact tests, where the headform was fired into the vehicle at 35 km/h at various locations on a car, the computed acceleration based HIC varied depending on the vehicle impact locations. The HIC was reduced by 10–38% for impacts headforms with a child helmet when the impact was onto a bonnet-top and roof header although the HIC was already less than 1000 in impacts with the headform without a child helmet. Similarly, for impacts into the windshield (where a cyclist’s head is most frequently impacted), the HIC using the adult headform without a child helmet was 122; whereas when the adult headform was used with a child helmet, a higher HIC value of more than 850 was recorded. But again, the HIC values are below 1000. In impacts into the A-pillar, the HIC was 4816 for a headform without a child helmet and was reduced by 18–38% for a headform with a child helmet depending on the type of Japanese child helmet used. The tests demonstrated that Japanese child helmets are effective in reducing accelerations and HIC in a drop test using an adult headform onto a relatively rigid hard surface, i.e., simulating a road surface or concrete path. However, when the impact tests are into softer surfaces, the child helmet’s capacity to decrease accelerations is accordingly reduced. Impacts into the windshield, while below the critical HIC value of 1000, indicated higher HIC values for a headform with a child helmet compared to an adult headform without a child helmet. The unpredictable nature of the results indicates further research work is required to assess how representative the stiffness of an adult headform is when compared to an actual head.
  • Article
    Interrupted time series analysis differs from most other intervention study designs in that it involves a before-after comparison within a single population, rather than a comparison with a control group. This has the advantage that selection bias and confounding due to between-group differences are limited. However, the basic interrupted time series design cannot exclude confounding due to co-interventions or other events occurring around the time of the intervention. One approach to minimizse potential confounding from such simultaneous events is to add a control series so that there is both a before-after comparison and an intervention-control group comparison. A range of different types of controls can be used with interrupted time series designs, each of which has associated strengths and limitations. Researchers undertaking controlled interrupted time series studies should carefully consider a priori what confounding events may exist and whether different controls can exclude these or if they could introduce new sources of bias to the study. A prudent approach to the design, analysis and interpretation of controlled interrupted time series studies is required to ensure that valid information on the effectiveness of health interventions can be ascertained.
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    The process of social adaptation of discharged servicemen requires the application of integrated approaches embracing different aspects and elements. Current study presents a competence model for social adaptation of discharged servicemen in Bulgaria as an example. It provides important implications on the concept of competences acquiring and the application of lifelong learning. The model is built on the basis of identifying key competencies as a starting point in accordance to contemporary trends, social and educational policies. Thus it appears to be feasible and could be successfully developed and applied into the practice.
  • Article
    Cycling has become increasingly common in the United Kingdom (UK) but so too have injuries related to cycling accidents. There is presently little data on the health of people cycling in the UK. Data were collected using an online questionnaire from 4961 cyclists (mean age 47.9 yrs, 79.2% men) contacted through large UK cycling organisation networks. The questionnaire collected information on participant demographics, self-reported cycling behaviour and cycling accident-related injury. Main outcome was suffering an injury related to a cycling accident in last five years. 54.3% of the sample reported a cycling accident resulting in injury. In multivariate adjusted models, accidents were associated with age (over 60׳s had lowest risk; OR: 0.61, 95% CI, 0.47–0.78), gender (women lower risk than men; 0.86, 0.75–1.00), weekly cycling distance in a dose-dependent manner (>160 km/wk; 2.44, 2.02–2.94), cycling experience (curvilinear association), commuting (1.33, 1.17–1.51), use of various safety equipment, always stopping at red signals (0.86, 0.73–0.99), and regular use of minor roads as oppose to major roads (0.80, 0.68–0.94). There were 842 reported head injuries, 15% of which required an overnight stay in hospital. Helmet use was associated with lower odds of being admitted overnight (0.59, 0.40–0.86). Our results represent the largest health survey of UK cyclists to date and reflect the experience of many UK cyclists regarding accident related-injury.
  • Article
    Full-text available
    Objectives The purpose of this study was to calculate exposure-based bicycling hospitalisation rates in Canadian jurisdictions with different helmet legislation and bicycling mode shares, and to examine whether the rates were related to these differences. Methods Administrative data on hospital stays for bicycling injuries to 10 body region groups and national survey data on bicycling trips were used to calculate hospitalisation rates. Rates were calculated for 44 sex, age and jurisdiction strata for all injury causes and 22 age and jurisdiction strata for traffic-related injury causes. Inferential analyses examined associations between hospitalisation rates and sex, age group, helmet legislation and bicycling mode share. Results In Canada, over the study period 2006–2011, there was an average of 3690 hospitalisations per year and an estimated 593 million annual trips by bicycle among people 12 years of age and older, for a cycling hospitalisation rate of 622 per 100 million trips (95% CI 611 to 633). Hospitalisation rates varied substantially across the jurisdiction, age and sex strata, but only two characteristics explained this variability. For all injury causes, sex was associated with hospitalisation rates; females had rates consistently lower than males. For traffic-related injury causes, higher cycling mode share was consistently associated with lower hospitalisation rates. Helmet legislation was not associated with hospitalisation rates for brain, head, scalp, skull, face or neck injuries. Conclusions These results suggest that transportation and health policymakers who aim to reduce bicycling injury rates in the population should focus on factors related to increased cycling mode share and female cycling choices. Bicycling routes designed to be physically separated from traffic or along quiet streets fit both these criteria and are associated with lower relative risks of injury.
  • Article
    Aim To investigate the use and protective effect of helmets in children injured in bicycle crashes and changes in injury patterns during a period of increased helmet use. Method Injuries in 4246 children below 16 years of age, who attended an A&E ward after a bicycle crash in the Gothenburg region during 1993–2006, were analyzed. The injury severity was classified according to the Abbreviated Injury Scale. The occurrence of skull/brain injuries and facial injuries was analyzed for 3711 children with respect to injury severity, helmet use and demographic and crash-related factors. Changes in injury patterns during the period were analyzed for 4246 children with no regard to helmet use. The ratio of the number of subjects with head injuries to the number of subjects with extremity injuries of any severity and of at least moderate severity was used to estimate the protective effect of helmet at a population level. Results Helmets were used by 40% of the injured children at the beginning of the period and by 80% at the end; much less frequently by teenagers, especially girls. The adjusted odds of serious or more severe skull/brain injuries and moderate or more severe facial injuries with a helmet were about one fourth of those without a helmet. The proportion of children with skull/brain injuries did not change significantly during the period. Serious or more severe skull/brain injuries were noted more often during the latter half of the period, most often in children without a helmet. The proportion of children with facial injuries decreased, and the proportion with injuries to the upper extremities increased, also for moderate and severe injuries. The ratio between the number of children with head injuries and the number with extremity injuries decreased for injuries of any severity and for moderate or more severe injuries. Conclusions Bicycle helmets have an obvious protective effect against head injuries in children, regardless of the crash circumstances. Teenagers must be informed about the high risk of skull/brain injuries in bicycle crashes without a helmet. The increasing occurrence of injuries to the upper extremities needs attention.
  • Article
    In 2003, Seattle implemented an all-ages bicycle helmet law; King County outside of Seattle had implemented a similar law since 1994. For the period 2000-2010, the effect of the helmet legislation on helmet use, helmet-preventable injuries, and bicycle-related fatalities was examined, comparing Seattle to the rest of King County. Data was retrieved from the Washington State Trauma Registry and the King County Medical Examiner. Results comparing the proportions of bicycle related head injuries before (2000-2002) and after (2004-2010) the law show no significant change in the proportion of bicyclists admitted to the hospital and treated for head injuries in either Seattle (37.9 vs 40.2 % p = 0.75) nor in the rest of King County (30.7 vs 31.4 %, p = 0.84) with the extension of the helmet law to Seattle in 2003. However, bicycle-related major head trauma as a proportion of all bicycle-related head trauma did decrease significantly in Seattle (83.9 vs 64.9 %, p = 0.04), while there was no significant change in King County (64.4 vs 57.6 %, p = 0.41). While the results do not show an overall decrease in head injuries, they do reveal a decrease in the severity of head injuries, as well as bicycle-related fatalities, suggesting that the helmet legislation was effective in reducing severe disability and death, contributing to injury prevention in Seattle and King County. The promotion of helmet use through an all ages helmet law is a vital preventative strategy for reducing major bicycle-related head trauma.
  • Article
    Background Past meta-analyses of studies assessing bicycle helmet efficacy have been criticised for poor methodology and the literature has not been systematically reviewed in over 15 years. The most recent meta-analysis reported time trend and publication biases, and found the summary odds ratio (OR) diminished when combining head, face and neck injuries. However, this study did not use standard methodology to identify biases, did not systematically review the literature, and the heterogeneity among studies reporting different injury outcomes was not assessed. The aim of this study is to systematically review and summarise results from studies assessing bicycle helmet efficacy to mitigate head, face and neck injury. Methods Four electronic databases were searched for relevant, peer-reviewed articles in English. Included studies reported medically diagnosed head, face or neck injuries, other cycling injuries and helmet usage. Non-approved helmets were excluded where possible. Summary ORs were obtained using mixed effects models stratified by injury type and severity. Time trends were tested using cumulative models and mixed models with time as a moderator. Evidence of publication bias was assessed using funnel plot methods. Results Study is ongoing with 53/70 studies assessed. Early results suggest bicycle helmets were associated with reduced odds of head and facial injuries, with the strength of association greater for more severe head injuries. Stratification by injury type and severity reduced heterogeneity. Early analyses do not suggest publication bias and no time effects were found from 1998 onwards. Conclusions A systematic search of the literature is essential for meta-analysis, especially when assessing publication bias. Inadequate assessment of heterogeneity among included studies partly accounts for discrepancies in previously reported results. We found helmets were associated with significant reductions in head injury for cyclists injured in a crash.
  • Conference Paper
    Full-text available
    Case‐control studies have found bicycle helmet use significantly mitigates the risk and severity of head injury in a motor vehicle collision. However, critics argue the decision to wear a helmet is confounded with other factors related to cycling safety such as cycling speed. If such an allocation bias exists, results from case‐ control studies may be invalid if confounding factors are ignored. Although allocation bias and bicycle helmet effectiveness is frequently mentioned in the literature, there is a paucity of research that has explored this relationship. This study aims to examine bicycle helmet effectiveness in a motor vehicle collision using the propensity score stratification method, which removes allocation bias from case (head injury) and control (no head injury) groups to allow for direct comparison of helmet effectiveness in reducing head injury. Due to privacy and data accessibility issues, synthetic data was created from a recently published Australian study of linked hospital and police data over a nine‐year period. In a motor vehicle collision, helmet use was associated with factors that have been argued to influence estimates of helmet effectiveness; however, using propensity score stratification, there is no evidence these confounding factors influence estimates of helmet effectiveness.
  • Article
    In the originally published version of this article, in Table 1, the study size for Otte and Wiese should have been given as 4245 instead of 245. Additionally, the last Dinh et al reference (#91) should have been 254 for the study size. This has now been corrected. © The Author 2017; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association Language: en Original Abstract Unaffected by the above correction of typographical erreo: Background: The research literature was systematically reviewed and results were summarized from studies assessing bicycle helmet effectiveness to mitigate head, serious head, face, neck and fatal head injury in a crash or fall. Methods: Four electronic databases (MEDLINE, EMBASE, COMPENDEX and SCOPUS) were searched for relevant, peer-reviewed articles in English. Included studies reported medically diagnosed head, face and neck injuries where helmet use was known. Non-approved helmets were excluded where possible. Summary odds ratios (OR) were obtained using multivariate meta-regression models stratified by injury type and severity. Time trends and publication bias were assessed. Results: A total of 43 studies met inclusion criteria and 40 studies were included in the meta-analysis with data from over 64 000 injured cyclists. For cyclists involved in a crash or fall, helmet use was associated with odds reductions for head [OR = 0.49, 95% confidence interval (CI): 0.42–0.57), serious head (OR = 0.31, 95% CI: 0.25–0.37), face (OR = 0.67, 95% CI: 0.56–0.81) and fatal head injury (OR = 0.35, 95% CI: 0.14–0.88). No clear evidence of an association between helmet use and neck injury was found (OR = 0.96, 95% CI: 0.74–1.25). There was no evidence of time trends or publication bias. Conclusions: Bicycle helmet use was associated with reduced odds of head injury, serious head injury, facial injury and fatal head injury. The reduction was greater for serious or fatal head injury. Neck injury was rare and not associated with helmet use. These results support the use of strategies to increase the uptake of bicycle helmets as part of a comprehensive cycling safety plan.
  • Article
    Résumé Objectif Le but de ce travail était d’étudier l’origine et les caractéristiques des lésions liées à la pratique du vélo chez l’enfant afin de les prévenir. Méthodes Les données ont été extraites du logiciel URQUAL® des urgences pédiatriques du CHU de Reims entre 2007 et 2014. Étaient inclus les patients admis aux urgences pédiatriques suite à un accident de vélo. Les lésions étaient codées à l’aide de l’Abbreviated Injury Scale (AIS) qui définit la lésion et la gravité lésionnelle. Nous avions réalisé une analyse descriptive des données avant d’utiliser les tests du χ² et de Fisher afin de différencier les groupes d’âge et de sexe. Résultats Au total, 2060 patients ont été inclus dans l’étude ; soit 2960 lésions traumatiques. Le nombre de consultations par an était stable. Les accidents liés à une pratique acrobatique du vélo et les collisions avec un véhicule à moteur étaient plus représentés chez les enfants de 10 ans et plus (p respectivement 0,0002 et < 0,0001). Les lésions de l’extrémité céphalique représentaient 41 % de l’ensemble des lésions ; elles prédominaient chez les enfants de moins de 10 ans (p < 0,0001). Le groupe de sexe masculin présentait un nombre supérieur de lésions de gravité modérée à maximale (p = 0,0201). Conclusion Dans notre étude, les lésions liées à la pratique du vélo étaient variées. Celles intéressant l’extrémité céphalique prédominaient ; elles doivent être prévenues par le port d’un casque dès le plus jeune âge. Les futures actions de prévention devront impliquer les acteurs de santé, de prévention et les pouvoirs publics.
  • Article
    The paper presents a model for social and psychological assistance to militaries discharged of service and the members of their families through the example of Bulgaria which has the potential to be a basis for the creation of an adaptive program and setting up criteria for efficiency in it. The model implies a main recommendation, namely - gaining of key competences adequate to the civil socium and labor market requirements which should be extended in further research. The model is based on the process of the social adaptation – its essence, peculiarities and affecting factors, as well as key elements and mechanisms.
  • Article
    This article seeks to answer the question whether mandatory bicycle helmet laws deliver a net societal health benefit. The question is addressed using a simple model. The model recognizes a single health benefit--reduced head injuries--and a single health cost-increased morbidity due to foregone exercise from reduced cycling. Using estimates suggested in the literature on the effectiveness of helmets, the health benefits of cycling, head injury rates, and reductions in cycling leads to the following conclusions. In jurisdictions where cycling is safe, a helmet law is likely to have a large unintended negative health impact. In jurisdictions where cycling is relatively unsafe, helmets will do little to make it safer and a helmet law, under relatively extreme assumptions, may make a small positive contribution to net societal health. The model serves to focus the mandatory bicycle helmet law debate on overall health.
  • Evaluation of the Bicycle Helmet Wearing Law in Victoria During its First 12 Months
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    Cameron, M., Helman, L., Nelger, D., 1992. Evaluation of the Bicycle Helmet Wearing Law in Victoria During its First 12 Months. Monash University Accident Research Centre.
  • Barriers to Cycling in NSW. Premier's Council for Active Living
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  • The Effectiveness of Bicycle Helmets: A Review. Motor Acci-dents. Authority of NSW
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  • The Safety of Vulnerable Road Users in the Southern, Eastern and Central European Countries. European Transport Safety Council Effects of lowering the legal BAC to 0.08 on single-vehicle-nighttime fatal traffic crashes in 19 jurisdictions
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    Avenoso, A., Beckmann, J., 2005. The Safety of Vulnerable Road Users in the Southern, Eastern and Central European Countries. European Transport Safety Council, Brussels. Bernat, D.H., Dunsmuir, W.T.M., Wagenaar, A.C., 2004. Effects of lowering the legal BAC to 0.08 on single-vehicle-nighttime fatal traffic crashes in 19 jurisdictions. Accid. Anal. Prev. 36 (6), 1089–1097.
  • The X-11 Variant of the Census Method II Seasonal Adjustment Program US Department of Commerce, Bureau of the Census Pedestrian and Cyclist Impact, A Biomechanical Perspec-tive An observational survey of law compliance and hel-met wearing by bicyclists in New
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  • An observational survey of law compliance and helmet wearing by bicyclists in New South Wales – 1993
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  • Historical Population Statistics
    Australian Bureau of Statistics, 2008. Historical Population Statistics, 2008. ABS, Canberra.
  • Retraction of the Voukelatos and Rissel paper on bicycle helmet legislation and injury
    Australasian College of Road Safety (ACRS), 2011. Retraction of the Voukelatos and Rissel paper on bicycle helmet legislation and injury. J. Aust. Coll. Road Saf. 22 (1), 39.
  • New South Wales BikePlan. Roads and Traffic Authority
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    NSW BikePlan, 2010. New South Wales BikePlan. Roads and Traffic Authority, Department of Environment, Climate Change and Water, Sydney.
  • Traffic Accident Database System Data Manual. Roads and Traffic Authority of NSW
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  • Article
    The scientific evidence that bicycle helmets protect against head, brain and facial injuries has been well established by 5 well designed case-control studies. Additional evidence of helmet effectiveness has been provided from time series studies in Australia and the US. Bicycle helmets of all types that meet various national and international standards provide substantial protection for cyclists of all ages who are involved in a bicycle crash. This protection extends to crashes from a variety of causes (such as falls and collisions with fixed and moving objects) and includes crashes involving motor vehicles. Helmet use reduces the risk of head injury by 85%, brain injury by 88% and severe brain injury by at least 75%. Helmets should be worn by all riders whether the cyclist is a recreational rider or a serious competitor engaged in training or race competition. The International Cycling Federation (ICF) should make the use of helmets compulsory in all sanctioned races.
  • Article
    Full-text available
    Legislation for the mandatory use of bicycle helmets is a controversial issue. The analysis presented in this paper examines the ratio of cycling-related head to arm injuries using hospital admissions data in New South Wales. The analysis is based on the idea that even if the numbers of cyclists has dropped over time, the relative injury rates (head versus arm) should remain unchanged unless some factor is differentially impacting on one type of injury, for example, helmet use reducing head injuries but not affecting arm injuries. Results indicate that there was already a fall in the ratio of head to arm injuries before the mandatory helmet legislation was introduced in 1991. After the introduction of bicycle helmet legislation, there was a continued but declining reduction in the ratio of head injuries relative to arm injuries for most age groups. It is likely that factors other than the mandatory helmet legislation reduced head injuries among cyclists.
  • Article
    This book is aimed at understanding the physical processes which occur when pedestrians and cyclists are struck by motorised vehicles. We provide a clear overview of the importance of pedestrian and cyclist impacts and the principal goals are to show how pedestrian and cyclist pre-impact movements and vehicle design influence subsequent injury outcome. This involves recourse to several academic disciplines: epidemiology, mechanics and anatomy/physiology. Therefore, this book presents pedestrian and cyclist impact from a biomechanical perspective.
  • Article
    Over 20 states have adopted laws requiring youths to wear a helmet when riding a bicycle. We confirm previous research indicating that these laws reduced fatalities and increased helmet use, but we also show that the laws significantly reduced youth bicycling. We find this result in standard two-way fixed effects models of parental reports of youth bicycling, as well as in triple difference models of self-reported bicycling among high school youths that explicitly account for bicycling by youths just above the helmet law age threshold. Our results highlight important intended and unintended consequences of a well-intentioned public policy.
  • Article
    In a survey of 1,402 current and potential cyclists in Metro Vancouver, 73 motivators and deterrents of cycling were evaluated. The top motivators, consistent among regular, frequent, occasional and potential cyclists, were: routes away from traffic noise and pollution; routes with beautiful scenery; and paths separated from traffic.In factor analysis, the 73 survey items were grouped into 15 factors. The following factors had the most influence on likelihood of cycling: safety; ease of cycling; weather conditions; route conditions; and interactions with motor vehicles. These results indicate the importance of the location and design of bicycle routes to promote cycling. KeywordsBicycle-Survey-Infrastructure-Influence-Non-motorized transport
  • Evaluation of the Bicycle Helmet Wearing Law in Victoria During its First Four Years. Monash University Accident Research Centre, Melbourne. Churches, T., 2010. Data and graphing errors in the Voukelatos and Rissel paper
    • D Carr
    • M Skalova
    • M Cameron
    Carr, D., Skalova, M., Cameron, M., 1995. Evaluation of the Bicycle Helmet Wearing Law in Victoria During its First Four Years. Monash University Accident Research Centre, Melbourne. Churches, T., 2010. Data and graphing errors in the Voukelatos and Rissel paper. J. Aust. Coll. Road Saf. 21 (4), 62–64.
  • Article
    Cycling is a popular past-time among children and adults and is highly beneficial as a means of transport and obtaining exercise. However, cycling related injuries are common and can be severe, particularly injuries to the head. Bicycle helmets have been advocated as a means of reducing the severity of head injuries, however voluntary use of helmets is low among the general population. Bicycle helmet laws mandating their use have thus been implemented in a number of jurisdictions word-wide in order to increase helmet use. These laws have proved to be controversial with opponents arguing that the laws may dissuade people from cycling or may result in greater injury rates among cyclists due to risk compensation. This review searched for the best evidence to investigate what effect bicycle helmet laws have had. There were no randomised controlled trials found, however five studies with a contemporary control were located that looked at bicycle related head injury or bicycle helmet use. The results of these studies indicated a positive effect of bicycle helmet laws for increasing helmet use and reducing head injuries in the target population compared to controls (either jurisdictions without helmet laws or non-target populations). None of the included studies measured actual bicycle use so it was not possible to evaluate the claim that fewer individuals were cycling due to the implementation of the helmet laws. Although the results of the review support bicycle helmet legislation for reducing head injuries, the evidence is currently insufficient to either support or negate the claims of bicycle helmet opponents that helmet laws may discourage cycling.
  • Article
    - Introduces GLMs in a way that enables readers to understand the unifying structure that underpins them. - Discusses common concepts and principles of advanced GLMs, including nominal and ordinal regression, survival analysis, and longitudinal analysis. - Connects Bayesian analysis and MCMC methods to fit GLMs. - Contains numerous examples from business, medicine, engineering, and the social sciences. - Provides the example code for R, Stata, and WinBUGS to encourage implementation of the methods. - Offers the data sets and solutions to the exercises online. Continuing to emphasize numerical and graphical methods, An Introduction to Generalized Linear Models, Third Edition provides a cohesive framework for statistical modeling. This new edition of a bestseller has been updated with Stata, R, and WinBUGS code as well as three new chapters on Bayesian analysis. Like its predecessor, this edition presents the theoretical background of generalized linear models (GLMs) before focusing on methods for analyzing particular kinds of data. It covers normal, Poisson, and binomial distributions; linear regression models; classical estimation and model fitting methods; and frequentist methods of statistical inference. After forming this foundation, the authors explore multiple linear regression, analysis of variance (ANOVA), logistic regression, log-linear models, survival analysis, multilevel modeling, Bayesian models, and Markov chain Monte Carlo (MCMC) methods. Using popular statistical software programs, this concise and accessible text illustrates practical approaches to estimation, model fitting, and model comparisons. It includes examples and exercises with complete data sets for nearly all the models covered.
  • Article
    On July 1, 1990, a law requiring wearing of an approved safety helmet by all bicyclists (unless exempted) came into effect in Victoria, Australia. Some of the more important steps that paved the way for this important initiative (believed to be the first statewide legislation of its type in the world) are described, and the initiative's effects are analysed. There was an immediate increase in average helmet-wearing rates from 31% in March 1990 to 75% in March 1991, although teenagers continued to show lower rates than younger children and adults. The number of insurance claims from bicyclists killed or admitted to hospital after sustaining a head injury decreased by 48% and 70% in the first and second years after the law, respectively. Analysis of the injury data also showed a 23% and 28% reduction in the number of bicyclists killed or admitted to hospital who did not sustain head injuries in the first and second post-law years, respectively. For Melbourne, where regular annual surveys of helmet wearing have been conducted, it was possible to fit a logistic regression model that related the reduction in head injuries to increased helmet wearing. Surveys in Melbourne also indicated a 36% reduction in bicycle use by children during the first year of the law and an estimated increase in adult use of 44%.
  • Article
    To describe the impact of a community bicycle helmet campaign on helmet use and the incidence of bicycle-related head injuries. Metropolitan community and a large health maintenance organization. Communitywide bicycle helmet campaign. Rate of observed bicycle helmet use in the community and incidence of bicycle-related injuries in an health maintenance organization population. Helmet use among school-aged children increased from 5.5% in 1987 to 40.2% in 1992. Bicycle-related head injuries decreased by 66.6% in 5- to 9-year-old and 67.6% in 10- to 14-year-old members of an health maintenance organization. Educational campaigns can increase helmet use and decrease the incidence of bicycle-related head injury.
  • Article
    The first year of the mandatory bicycle helmet laws in Australia saw increased helmet wearing from 31% to 75% of cyclists in Victoria and from 31% of children and 26% of adults in New South Wales (NSW) to 76% and 85%. However, the two major surveys using matched before and after samples in Melbourne (Finch et al. 1993; Report No. 45, Monash Univ. Accident Research Centre) and throughout NSW (Smith and Milthorpe 1993; Roads and Traffic Authority) observed reductions in numbers of child cyclists 15 and 2.2 times greater than the increase in numbers of children wearing helmets. This suggests the greatest effect of the helmet law was not to encourage cyclists to wear helmets, but to discourage cycling. In contrast, despite increases to at least 75% helmet wearing, the proportion of head injuries in cyclists admitted or treated at hospital declined by an average of only 13%. The percentage of cyclists with head injuries after collisions with motor vehicles in Victoria declined by more, but the proportion of head injured pedestrians also declined; the two followed a very similar trend. These trends may have been caused by major road safety initiatives introduced at the same time as the helmet law and directed at both speeding and drink-driving. The initiatives seem to have been remarkably effective in reducing road trauma for all road users, perhaps affecting the proportions of victims suffering head injuries as well as total injuries. The benefits of cycling, even without a helmet, have been estimated to outweigh the hazards by a factor of 20 to 1 (Hillman 1993. Cycle helmets-the case for and against. Policy Studies Institute, London). Consequently, a helmet law, whose most notable effect was to reduce cycling, may have generated a net loss of health benefits to the nation. Despite the risk of dying from head injury per hour being similar for unhelmeted cyclists and motor vehicle occupants, cyclists alone have been required to wear head protection. Helmets for motor vehicle occupants are now being marketed and a mandatory helmet law for these road users has the potential to save 17 times as many people from death by head injury as a helmet law for cyclists without the adverse effects of discouraging a healthy and pollution free mode of transport.
  • Article
    The scientific evidence that bicycle helmets protect against head, brain and facial injuries has been well established by 5 well designed case-control studies. Additional evidence of helmet effectiveness has been provided from time series studies in Australia and the US. Bicycle helmets of all types that meet various national and international standards provide substantial protection for cyclists of all ages who are involved in a bicycle crash. This protection extends to crashes from a variety of causes (such as falls and collisions with fixed and moving objects) and includes crashes involving motor vehicles. Helmet use reduces the risk of head injury by 85%, brain injury by 88% and severe brain injury by at least 75%. Helmets should be worn by all riders whether the cyclist is a recreational rider or a serious competitor engaged in training or race competition. The International Cycling Federation (ICF) should make the use of helmets compulsory in all sanctioned races.
  • Article
    Since late 1989, the cycle helmet wearing rate in New Zealand has risen from around 20% for adults and teenagers, and 40% for younger children, to more than 90% in all age groups. Cycle helmet wearing became mandatory under New Zealand law in January 1994. This paper considers the effect of cycle helmet wearing on hospitalised head injuries between 1990 and 1996, using cyclist limb injuries as a measure of exposure to the risk of cycling trauma. Non-motor vehicle crashes were treated separately from those involving a motor vehicle. Non-motor vehicle crashes were further subdivided by age group. Cyclist head injuries decreased with increasing helmet wearing rates for non-motor vehicle crashes in all age groups, and for motor vehicle crashes. For an increase of 5 percentage points in the helmet wearing rate, the corresponding decreases in head injuries in non-motor vehicle accidents were estimated to be 10.2, 5.3 and 3.2% for children of primary school age (5-12 years), secondary school age (13-18 years), and adults respectively. The corresponding decrease in hospitalisations for motor vehicle crashes was 3.6%. All results were significant at the 95% level. The relatively large increase in helmet wearing associated with the passing of a compulsory helmet wearing law in 1994 reduced head injuries by between 24 and 32% in non-motor vehicle crashes, and by 20% in motor vehicle crashes. No increase or decrease in the severity of head injuries for which cyclists were hospitalised over this period could be detected. This may have been due to the small and highly variable number of 'high severity' injuries.
  • Article
    The purpose of this study was to examine the effect of helmet wearing and the New Zealand helmet wearing law on serious head injury for cyclists involved in on-road motor vehicle and non-motor vehicle crashes. The study population consisted of three age groups of cyclists (primary school children (ages 5-12 years), secondary school children (ages 13-18 years), and adults (19+ years)) admitted to public hospitals between 1988 and 1996. Data were disaggregated by diagnosis and analysed using negative binomial regression models. Results indicated that there was a positive effect of helmet wearing upon head injury and this effect was relatively consistent across age groups and head injury (diagnosis) types. We conclude that the helmet law has been an effective road safety intervention that has lead to a 19% (90% CI: 14, 23%) reduction in head injury to cyclists over its first 3 years.
  • Article
    Bicycle helmet efficacy was quantified using a formal meta-analytic approach based on peer-reviewed studies. Only those studies with individual injury and helmet use data were included. Based on studies from several countries published in the period 1987-1998, the summary odds ratio estimate for efficacy is 0.40 (95% confidence interval 0.29, 0.55) for head injury, 0.42 (0.26, 0.67) for brain injury, 0.53 (0.39, 0.73) for facial injury and 0.27 (0.10, 0.71) for fatal injury. This indicates a statistically significant protective effect of helmets. Three studies provided neck injury results that were unfavourable to helmets with a summary estimate of 1.36 (1.00, 1.86), but this result may not be applicable to the lighter helmets currently in use. In conclusion, the evidence is clear that bicycle helmets prevent serious injury and even death. Despite this, the use of helmets is sub-optimal. Helmet use for all riders should be further encouraged to the extent that it is uniformly accepted and analogous to the use of seat belts by motor vehicle occupants.
  • Article
    Each year, in the United states, approximately 900 persons die from injuries due to bicycle crashes and over 500,000 persons are treated in emergency departments. Head injury is by far the greatest risk posed to bicyclists, comprising one-third of emergency department visits, two-thirds of hospital admissions, and three-fourths of deaths. Facial injuries to cyclists occur at a rate nearly identical to that of head injuries. Although it makes inherent sense that helmets would be protective against head injury, establishing the real-world effectiveness of helmets is important. A number of case-control studies have been conducted demonstrating the effectiveness of bicycle helmets. Because of the magnitude of the problem and the potential effectiveness of bicycle helmets, the objective of this review is to determine whether bicycle helmets reduce head, brain and facial injury for bicyclists of all ages involved in a bicycle crash or fall. To determine whether bicycle helmets reduce head, brain and facial injury for bicyclists of all ages involved in a bicycle crash or fall. We searched The Cochrane Controlled Trials Register, MEDLINE, EMBASE, Sport, ERIC, NTIS, Expanded Academic Index, CINAHL, PsycINFO, Occupational Safety and Health, and Dissertations Abstracts. We checked reference lists of past reviews and review articles, studies from government agencies in the United States, Europe and Australia, and contacted colleagues from the International Society for Child and Adolescent Injury Prevention, World Injury Network, CDC funded Injury Control and Research Centers, and staff in injury research agencies around the world. Controlled studies that evaluated the effect of helmet use in a population of bicyclists who had experienced a crash. We required that studies have complete outcome ascertainment, accurate exposure measurement, appropriate selection of the comparison group and elimination or control of factors such as selection bias, observation bias and confounding. Five published studies met the selection criteria. Two abstractors using a standard abstraction form independently abstracted data. Odds ratios with 95% CI were calculated for the protective effect of helmet for head and facial injuries. Study results are presented individually. Head and brain injury results were also summarized using meta-analysis techniques. No randomized controlled trials were found. This review identified five well conducted case control studies which met our selection criteria. Helmets provide a 63%-88% reduction in the risk of head, brain and severe brain injury for all ages of bicyclists. Helmets provide equal levels of protection for crashes involving motor vehicles (69%) and crashes from all other causes (68%). Injuries to the upper and mid facial areas are reduced 65%. Helmets reduce bicycle-related head and facial injuries for bicyclists of all ages involved in all types of crashes including those involving motor vehicles.
  • Article
    Full-text available
    Childhood bicycle-related head injuries can be prevented through the use of helmets. Although helmet legislation has proved to be a successful strategy for the adoption of helmets, its effect on the rates of head injury is uncertain. In Canada, 4 provinces have such legislation. The objective of this study was to measure the impact of helmet legislation on bicycle-related head injuries in Canadian children. Routinely collected data from the Canadian Institute for Health Information identified all Canadian children (5-19 years) who were hospitalized for bicycling-related injuries from 1994-1998. Children were categorized as head or other injury on the basis of International Classification of Diseases, Ninth Revision, codes. Rates of head injuries and other injuries were compared over time in provinces that adopted legislation and those that did not. Of the 9650 children who were hospitalized because of a bicycle-related injury, 3426 sustained injuries to the head and face and the remaining 6224 had other injuries. The bicycle-related head injury rate declined significantly (45% reduction) in provinces where legislation had been adopted compared with provinces and territories that did not adopt legislation (27% reduction). This country-wide study compared rates of head injury in regions with and without mandatory helmet legislation. Comparing head injuries with other non-head-injured children controlled for potential differences in children's cycling habits. The strong protective association between helmet legislation and head injuries supports the adoption of helmet legislation as an effective tool in the prevention of childhood bicycle-related head injuries.
  • Article
    To obtain empirical data that might support or refute the existence of a risk compensation mechanism in connection with voluntary helmet use by Spanish cyclists. A retrospective case series. Spain, from 1990 to 1999. All 22 814 cyclists involved in traffic crashes with victims, recorded in the Spanish Register of Traffic Crashes with Victims, for whom information regarding helmet use was available. Crude and adjusted odds ratios for the relation between committing a traffic violation and using a helmet. Fifty four percent of the cyclists committed a traffic violation other than a speeding infraction. Committing a traffic violation was associated with a lower frequency of helmet use (adjusted odds ratio (aOR) 0.63, 95% confidence interval (CI) 0.58 to 0.69). Cycling at excessive or dangerous speed, a violation observed in 4.5% of the sample, was not significantly associated with helmet use either alone (aOR 0.95, 95% CI 0.56 to 1.61) or in combination with any other violation (aOR 0.97, 95% CI 0.79 to 1.20). The results suggest that the subgroup of cyclists with a higher risk of suffering a traffic crash are also those in which the health consequences of the crash will probably be higher. Although the findings do not support the existence of a strong risk compensation mechanism among helmeted cyclists, this possibility cannot be ruled out.
  • Article
    To examine the relationship between the numbers of people walking or bicycling and the frequency of collisions between motorists and walkers or bicyclists. The common wisdom holds that the number of collisions varies directly with the amount of walking and bicycling. However, three published analyses of collision rates at specific intersections found a non-linear relationship, such that collisions rates declined with increases in the numbers of people walking or bicycling. This paper uses five additional data sets (three population level and two time series) to compare the amount of walking or bicycling and the injuries incurring in collisions with motor vehicles. The likelihood that a given person walking or bicycling will be struck by a motorist varies inversely with the amount of walking or bicycling. This pattern is consistent across communities of varying size, from specific intersections to cities and countries, and across time periods. This result is unexpected. Since it is unlikely that the people walking and bicycling become more cautious if their numbers are larger, it indicates that the behavior of motorists controls the likelihood of collisions with people walking and bicycling. It appears that motorists adjust their behavior in the presence of people walking and bicycling. There is an urgent need for further exploration of the human factors controlling motorist behavior in the presence of people walking and bicycling. A motorist is less likely to collide with a person walking and bicycling if more people walk or bicycle. Policies that increase the numbers of people walking and bicycling appear to be an effective route to improving the safety of people walking and bicycling.
  • Article
    In the past few decades, numerous policies, including those that lower legal blood alcohol concentration limits, have been enacted to reduce alcohol-impaired driving. In the US, 41 states and the District of Columbia have enacted 0.08 per se laws, which specify that if a driver's BAC is at or above 0.08, a violation has occurred even if the driver does not show signs of intoxication. We examined effects of lowering the blood alcohol concentration limit to 0.08 per se on fatal traffic crashes in 18 states and the District of Columbia, and whether effects of the law varied by state or by baseline rates of fatal traffic crashes. Data on fatal traffic crashes were obtained from the Fatality Analysis Reporting System, including all states that enacted 0.08 per se prior to 2001 in the contiguous United States. Effects of the 0.08 law were examined in each state separately, and the overall effect across states was examined using a mixed-model Poisson regression on single-vehicle-nighttime fatal traffic crashes. State-specific analyses showed that fatal traffic crashes significantly decreased in three of the 19 states following the introduction of the 0.08 law, prior to adjusting for potential confounders. The mixed-model regression showed a statistically significant 5.2% reduction in single-vehicle-nighttime fatal traffic crashes associated with the 0.08 law across all states, after adjusting for administrative license revocation, the number of Friday and Saturday nights in a month, and trends in all other types of fatal traffic crashes. Findings indicate that the effect of the 0.08 law does not vary significantly by state or baseline rate of fatal traffic crashes in a state, and no significant statistical interaction exists between 0.08 and administrative license revocation policy effects.
  • Article
    The objective of this study was to determine whether the bicycle safety helmet legislation in California, enacted in 1994, was associated with statistically significant reductions in head injuries among bicyclists aged 17 years and under who were subjected to the law. The study used 44,069 patient discharge cases from all public hospitals in California, from 1991 through 2000, and a case-control design to make direct comparisons between those subjected to the law (Youth) and those who were not (Adult) across the pre- and post-legislation periods. An aggregate data analysis approach and a pooled disaggregate data fitting technique using multinomial logit models were applied. The legislation was found to be associated with a reduction of 18.2% (99% confidence interval: 11.5-24.3%) in the proportion of traumatic brain injuries (Head-TBI) among Youth bicyclists. The proportions of other head, face, and neck injuries were not significantly changed across the pre- and post-legislation periods in this age group but there was a corresponding increase of 9% (5-13%) in the proportion of all other injuries. On the other hand, there was no statistically significant change in the proportions of injury outcomes for Adult bicyclists. The youngest riders, aged 0-9 years, had the greatest decrease in the proportion of Head-TBI. The reduction was the same for motor vehicle and non-motor-vehicle-related incidents. The bicycle safety helmet legislation was associated with a decrease in the likelihood of Head-TBI for non-urban residents but not for urbanites, for males but not for females, and for Whites, Asians, and Hispanics, but not Blacks and others.
  • Article
    Effective interventions for care of health need to be based on scientific evidence. To this end, the Cochrane Collaboration insists that its reviews should be based on reliable data, normally obtained by randomised controlled trial. To constitute evidence, data should also support a hypothesis in accord with scientific laws and knowledge. From these considerations, an appraisal is made of the conclusion of the Cochrane review Helmets for preventing head and facial injuries in bicyclists, that it establishes scientific evidence that all types of standard helmet protect against injuries to the brain. It is concluded that the review takes no account of scientific knowledge of types and mechanisms of brain injury. It provides, at best, evidence that hard-shell helmets, now rarely used, protect the brain from injury consequent upon damage to the skull. The review therefore is not a reliable guide to the efficacy of helmets and to interventions concerning their use.
  • Article
    Full-text available
    Overseas research shows that fatality and injury risks per cyclist and pedestrian are lower when there are more cyclists and pedestrians. Do Australian data follow the same exponential 'growth rule' where (Injuries)/(Amount of cycling) is proportional to ((Amount of cycling)-0.6)? Fatality and injury risks were compared using three datasets: 1) fatalities and amounts of cycling in Australian States in the 1980s; 2) fatality and injury rates over time in Western Australia as cycling levels increased; and 3) deaths, serious head injuries and other serious injuries to cyclists and pedestrians in Victoria, before and after the fall in cycling with the helmet law. In Australia, the risks of fatality and injury per cyclist are lower when cycling is more prevalent. Cycling was safest and most popular in the Australian Capital Territory (ACT), Queensland and Western Australia (WA). New South Wales residents cycled only 47% as much as residents of Queensland and WA, but had 53% more fatalities per kilometre, consistent with the growth rule prediction of 52% more for half as much cycling. Cycling also became safer in WA as more people cycled. Hospitalisation rates per 10,000 regular cyclists fell from 29 to 15, and reported deaths and serious injuries from 5.6 to 3.8 as numbers of regular cyclists increased. In Victoria, after the introduction of compulsory helmets, there was a 30% reduction in cycling and it was associated with a higher risk of death or serious injury per cyclist, outweighing any benefits of increased helmet wearing. As with overseas data, the exponential growth rule fits Australian data well. If cycling doubles, the risk per kilometre falls by about 34%; conversely, if cycling halves, the risk per kilometre will be about 52% higher. Policies that adversely influence the amount of cycling (for example, compulsory helmet legislation) should be reviewed.
  • Article
    Full-text available
    Case-control studies suggest that cyclists who choose to wear helmets have fewer head injuries than non-wearers. Consequently, the BMA recommended that the United Kingdom introduce and enforce bicycle helmet laws.1 However, regular exercise such as cycling is beneficial to health, and non-helmeted commuter cyclists have lower mortality than non-cyclists.2 Helmet laws would be counterproductive if they discouraged cycling and increased car use. Wearing helmets may also encourage cyclists to take more risks, or motorists to take less care when they encounter cyclists.3 Recent epidemiological research highlighted problems adjusting for confounders in observational studies, causing biased, misleading results.4 Thus the best estimate of the benefits of helmet laws is what actually happens when laws are passed. I reviewed 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, I have 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. Details of data sources and methods are given on bmj.com.
  • Article
    This paper is a rebuttal of the criticism by Hagel and Pless of my 2005 article in which I dispute the conclusion of a Cochrane Collaboration review that all types of standard bicycle helmet protect against injury to the brain. The main ground of rebuttal is that my critics take the relevant efficacy of helmets as given and argue from there.
  • Article
    Debate continues over bicycle helmet laws. Proponents argue that case-control studies of voluntary wearing show helmets reduce head injuries. Opponents argue, even when legislation substantially increased percent helmet wearing, there was no obvious response in percentages of cyclist hospital admissions with head injury-trends for cyclists were virtually identical to those of other road users. Moreover, enforced laws discourage cycling, increasing the costs to society of obesity and lack of exercise and reducing overall safety of cycling through reduced safety in numbers. Countries with low helmet wearing have more cyclists and lower fatality rates per kilometre. Cost-benefit analyses are a useful tool to determine if interventions are worthwhile. The two published cost-benefit analyses of helmet law data found that the cost of buying helmets to satisfy legislation probably exceeded any savings in reduced head injuries. Analyses of other road safety measures, e.g. reducing speeding and drink-driving or treating accident blackspots, often show that benefits are significantly greater than costs. Assuming all parties agree that helmet laws should not be implemented unless benefits exceed costs, agreement is needed on how to derive monetary values for the consequences of helmet laws, including changes in injury rates, cycle-use and enjoyment of cycling. Suggestions are made concerning the data and methodology needed to help clarify the issue, e.g. relating pre- and post-law surveys of cycle use to numbers with head and other injuries and ensuring that trends are not confused with effects of increased helmet wearing.
  • Article
    This paper replies to criticism by Cummings et al. [Cummings, P., Rivara, F.P., Thompson, D.C., Thompson, R.S., 2006. Accid. Anal. Prev. 38, 636-643] of an article [Curnow, W.J., 2005. The Cochrane Collaboration and bicycle helmets. Accid. Anal. Prev. 37, 569-573] disputing a conclusion of a Cochrane Collaboration review, namely, that it establishes scientific evidence that all types of standard bicycle helmet protect against injury to the brain. In response to the conclusion of Cummings that the review's case-control studies provide such evidence, I explain that their design is inadequate to do this.