The Effect of an All-Ages Bicycle Helmet Law on Bicycle-Related Trauma

Effectiveness of road safety interventions: An evidence and gap map

Background

Road Traffic injuries (RTI) are among the top ten leading causes of death in the world resulting in 1.35 million deaths every year, about 93% of which occur in low- and middle-income countries (LMICs). Despite several global resolutions to reduce traffic injuries, they have continued to grow in many countries. Many high-income countries have successfully reduced RTI by using a public health approach and implementing evidence-based interventions. As many LMICs develop their highway infrastructure, adopting a similar scientific approach towards road safety is crucial. The evidence also needs to be evaluated to assess external validity because measures that have worked in high-income countries may not translate equally well to other contexts. An evidence gap map for RTI is the first step towards understanding what evidence is available, from where, and the key gaps in knowledge.

Objectives

The objective of this evidence gap map (EGM) is to identify existing evidence from all effectiveness studies and systematic reviews related to road safety interventions. In addition, the EGM identifies gaps in evidence where new primary studies and systematic reviews could add value. This will help direct future research and discussions based on systematic evidence towards the approaches and interventions which are most effective in the road safety sector. This could enable the generation of evidence for informing policy at global, regional or national levels.

Search Methods

The EGM includes systematic reviews and impact evaluations assessing the effect of interventions for RTI reported in academic databases, organization websites, and grey literature sources. The studies were searched up to December 2019.

Selection Criteria

The interventions were divided into five broad categories: (a) human factors (e.g., enforcement or road user education), (b) road design, infrastructure and traffic control, (c) legal and institutional framework, (d) post-crash pre-hospital care, and (e) vehicle factors (except car design for occupant protection) and protective devices. Included studies reported two primary outcomes: fatal crashes and non-fatal injury crashes; and four intermediate outcomes: change in use of seat belts, change in use of helmets, change in speed, and change in alcohol/drug use. Studies were excluded if they did not report injury or fatality as one of the outcomes.

Data Collection and Analysis

The EGM is presented in the form of a matrix with two primary dimensions: interventions (rows) and outcomes (columns). Additional dimensions are country income groups, region, quality level for systematic reviews, type of study design used (e.g., case-control), type of road user studied (e.g., pedestrian, cyclists), age groups, and road type. The EGM is available online where the matrix of interventions and outcomes can be filtered by one or more dimensions. The webpage includes a bibliography of the selected studies and titles and abstracts available for preview. Quality appraisal for systematic reviews was conducted using a critical appraisal tool for systematic reviews, AMSTAR 2.

Main Results

The EGM identified 1859 studies of which 322 were systematic reviews, 7 were protocol studies and 1530 were impact evaluations. Some studies included more than one intervention, outcome, study method, or study region. The studies were distributed among intervention categories as: human factors (n = 771), road design, infrastructure and traffic control (n = 661), legal and institutional framework (n = 424), post-crash pre-hospital care (n = 118) and vehicle factors and protective devices (n = 111). Fatal crashes as outcomes were reported in 1414 records and non-fatal injury crashes in 1252 records. Among the four intermediate outcomes, speed was most commonly reported (n = 298) followed by alcohol (n = 206), use of seatbelts (n = 167), and use of helmets (n = 66). Ninety-six percent of the studies were reported from high-income countries (HIC), 4.5% from upper-middle-income countries, and only 1.4% from lower-middle and low-income countries. There were 25 systematic reviews of high quality, 4 of moderate quality, and 293 of low quality.

Authors' Conclusions

The EGM shows that the distribution of available road safety evidence is skewed across the world. A vast majority of the literature is from HICs. In contrast, only a small fraction of the literature reports on the many LMICs that are fast expanding their road infrastructure, experiencing rapid changes in traffic patterns, and witnessing growth in road injuries. This bias in literature explains why many interventions that are of high importance in the context of LMICs remain poorly studied. Besides, many interventions that have been tested only in HICs may not work equally effectively in LMICs. Another important finding was that a large majority of systematic reviews are of low quality. The scarcity of evidence on many important interventions and lack of good quality evidence-synthesis have significant implications for future road safety research and practice in LMICs. The EGM presented here will help identify priority areas for researchers, while directing practitioners and policy makers towards proven interventions.

Teens on Wheels and Consequences: A Six-Year Population-Based Study of Bicycle and Moped Injuries

INTRODUCTION

 Road traffic accidents are a major contributor to morbidity and mortality in the pediatric and adolescent population. Among adolescents, bicycles and light motorized two wheelers are popular means of transportation and increase adolescents' autonomy. Most previous studies on injury risk and incidence have pooled different vehicles and age groups together but more distinct data are required to guide policy.

MATERIALS AND METHODS

 We gathered data on all 1,432 children and adolescents (age 7-15) who had been treated for injuries from bicycle(n = 841) or moped/motorized scooter (n = 591) accidents at our study centers during a 6-year period (2008-2013). In addition to clinical data, we reviewed Injury Severity Scores (ISS) and calculated incidence estimates for the population of 15-year-olds in the study area.

RESULTS

 Most bicyclists were injured after a fall (72%), whereas most moped/scooter riders were injured in a collision (51%), most often with a heavier motorized vehicle. Internal injuries, multiple injuries, and severe injuries (ISS >15) were more common among moped/scooter riders than bicyclists (p < 0·001 for all). Moped/scooter riders were more often hospitalized and underwent more operations than bicyclists (p < 0·001 for both). The annual estimated incidence rates of injury were roughly eightfold for 15-year-old moped/scooter riders compared to bicyclists of the same age.

CONCLUSION

 Cycling is in general a safe mode of transportation and rider safety could be further increased with the proper use of helmets. Although no patient deaths occurred in this study population, mopeds and motorized scooters led to significant morbidity.

The Association of Payer Status and Injury Patterns in Pediatric Bicycle Injuries

BACKGROUND

Bicycle injuries continue to cause significant morbidity in the United States. How insurance status affects outcomes in children with bicycle injuries has not been defined. We hypothesized that payer status would not impact injury patterns or outcomes in pediatric bicycle-related accidents.

METHODS

The National Trauma Data Bank was used to identify pediatric (≤18 y) patients involved in bicycle-related crashes admitted in year 2016. Patients with private insurance were compared with all others (uninsured, Medicaid, and Medicare).

RESULTS

There were 5619 patients that met study criteria. Of these, 2500 (44%) had private insurance. Privately insured were older (12 y versus 11, P < 0.001), more likely to be white (77% versus 56%, P < 0.001), and more likely to wear a helmet (26% versus 9%, P < 0.001). On multivariate analysis, factors associated with traumatic brain injury included age (odds ratio [OR], 1.07; 95% confidence interval [CI], 1.06-1.08; P < 0.001) and helmet use (OR, 0.64; 95% CI, 0.55-0.74; P < 0.001). Patients without private insurance were significantly less likely to wear a helmet (OR, 0.52; 95% CI, 0.44-0.63; P < 0.001). Uninsured patients had significantly higher odds of a fatal injury (OR, 4.43; 95% CI, 1.52-12.92; P = 0.006).

CONCLUSIONS

Uninsured children that present to a trauma center after a bicycle accident are more likely to die. Although helmet use reduced the odds of traumatic brain injury, minorities and children without private insurance were less likely to be helmeted. Public health interventions should increase helmet access to children without private insurance, especially uninsured children.

Primary prevention of road traffic accident-related traumatic brain injuries in younger populations: a systematic review of helmet legislation

OBJECTIVE

Road traffic accidents are the most frequent cause of severe traumatic brain injury (TBI), particularly among young populations worldwide. Helmets are proven to prevent injuries; however, estimates of helmet compliance are low globally. Surgical/critical care management of TBI is often used to treat these injuries, but primary prevention should be recommended. A key component in promoting TBI prevention among pediatric and young populations is through helmet legislation. The authors investigated helmet policies for motorcycles and bicycles globally to provide recommendations for how related legislation may impact TBI and guide advocacy in pediatric neurosurgery.

METHODS

The authors conducted a systematic review of helmet laws and/or policies by using the National Library of Medicine PubMed and SCOPUS databases. Additional articles were identified using citation searches of key publications. Abstracts from articles of all sources were read and selected for full-text review. Details of relevant full articles were extracted and analyzed for the following: bibliographic data, study aim, design and duration, study participants, intervention characteristics, and intervention effect data.

RESULTS

Of 618 search results, 53 full-text articles were analyzed for recommendations. Helmet legislation is associated with increased helmet use among bicyclists and decreased road traffic accident-related head injuries and fatalities among motorcyclists and bicyclists. Laws are more effective if comprehensive and inclusive of the following: both primary riders and passengers, all age groups, all modes of transportation made safer by helmets, a proper use clause, and standardized helmet quality measures. Cultural, socioeconomic, and infrastructural circumstances are important as well, and legislation must consider enforcement mechanisms with penalties significant enough to incentivize behavioral changes, but proportional to community socioeconomic status.

CONCLUSIONS

Compulsory use laws are the optimal primary intervention; however, concurrent programs to support financial access to helmets, change cultural attitudes, increase health literacy, and improve road infrastructure will augment legislative benefits. Pediatric neurosurgeons are caretakers of children suffering from TBI. Although extensive study has explored the surgical management of TBI, the authors believe that primary prevention is instrumental to improving outcomes and reducing injury. All helmet laws are not equal; based on these findings, a comprehensive, context-specific approach is the key to success, especially in resource-limited countries.

Race and Insurance Status as Predictors of Bicycle Trauma Outcome in Adults

BACKGROUND

Race and insurance status have been shown to predict outcomes in pediatric bicycle traumas. It is unknown how these factors influence outcomes in adult bicycle traumas. This study aims to evaluate the association, if any, between race and insurance status with mortality in adults.

METHODS

This retrospective cohort study used the National Trauma Data Bank Research Data Set for the years 2013-2015. Multivariate logistic regression models were used to determine the independent association between patient race and insurance status on helmet use and on outcomes after hospitalization for bicycle-related injury. These models adjusted for demographic factors and comorbid variables. When examining the association between race and insurance status with outcomes after hospitalization, injury characteristics were also included.

RESULTS

A study population of 45,063 met the inclusion and exclusion criteria. Multivariate regression demonstrated that black adults and Hispanic adults were significantly less likely to be helmeted at the time of injury than white adults [adjusted odds ratio of helmet use for blacks 0.25 (95% CI 0.22-0.28) and for Hispanics 0.33 (95% CI 0.30-0.36) versus whites]. Helmet usage was also independently associated with insurance status, with Medicare-insured patients [AOR 0.51 (95% CI 0.47-0.56) versus private-insured patients], Medicaid-insured patients [AOR 0.18 (95% CI 0.17-0.20)], and uninsured patients [AOR 0.29 (95% CI 0.27-0.32)] being significantly less likely to be wearing a helmet at the time of injury compared with private-insured patients. Although patient race was not independently associated with hospital mortality among adult bicyclists, we found that uninsured patients had significantly higher odds of mortality [AOR 2.02 (AOR 1.31-3.12)] compared with private-insured patients.

CONCLUSIONS

Minorities and underinsured patients are significantly less likely to be helmeted at the time of bicycle-related trauma when compared with white patients and those with private insurance. Public health efforts to improve the utilization of helmets during bicycling should target these subpopulations.

Roadmap for free-floating bikeshare research and practice in North America

The deployment of smartphone-operated, non-station-based bicycle fleets ("dockless" or "free-floating" bikeshare) represents a new generation of bikesharing. Users locate bikes in these free-floating systems using Global Positioning Systems (GPS) and lock bikes in place at their destinations. In this paper, we review current free-floating bikesharing systems in North America and discuss priorities for future research and practice. Since launching in 2017, free-floating bikeshare has expanded rapidly to encompass 200+ systems operating 40,000+ bikes within 150+ cities. In contrast with previous systems, free-floating systems operate almost exclusively using commercial "for-profit" models, amidst concerns of financial sustainability. Governance for these systems is in early stages and can include operating fees, fleet size caps, safety requirements, parking restrictions, data sharing, and equity obligations. We identify research and practice gaps within the themes of usage, equity, sharing resources, business model, and context. While some existing bikesharing literature translates to free-floating systems, novel topics arise due to the ubiquity, fluidity, and business models of these new systems. Systems have numerous obstacles to overcome for long-term sustainability, including barriers common to station-based systems: limited supportive infrastructure, equity, theft or vandalism, and funding. Other unique obstacles arise in free-floating bikeshare around parking, sidewalk right of ways, varied bicycle types, and data sharing. This review offers background in and critical reflection on the rapidly evolving free-floating bikeshare landscape, including priorities for future research and practice. If concerns can be overcome, free-floating bikeshare may provide unprecedented opportunities to bypass congested streets, encourage physical activity, and support urban sustainability.

Free-Floating Bikeshare and Helmet Use in Seattle, WA

Wearing a helmet when bicycling prevents traumatic brain injury in the event of a crash. Most cyclists nationwide use helmets when riding. However, the growth of free-floating bike sharing systems, which offer short-term access to bicycles but not helmets, may erode helmet-wearing norms among cyclists. We counted cyclists over several hours at four locations in Seattle, WA. We categorized each rider according to whether he or she was wearing a helmet and to whether or not he or she was riding a bike share bike. Whereas 91% of riders of private bikes wore helmets, only 20% of bike share riders wore helmets. Moreover, in locations where a greater proportion of riders were on bikes hare bikes, fewer riders of private bicycles wore helmets (r = - 0.96, p = 0.04). The impact of bike sharing programs on helmet wearing norms among private bike riders warrants further exploration.

The impact of bicycle helmet legislation on cycling fatalities in Australia

Background

Australian bicycle helmet laws were first introduced in Victoria in July 1990 and the remaining Australian states, Australian Capital Territory and Northern Territory by July 1992. Previous research on helmet legislation has focused on changes in helmet wearing and bicycle-related head injury. Although it is generally accepted that bicycle helmets can reduce the risk of fatality due to head injury, there has been little research assessing the impact of helmet legislation on cycling fatalities.

Methods

An interrupted time series approach was used to assess the impact of bicycle helmet legislation on yearly-aggregated rates of bicycle-related fatalities per population from 1971 to 2016.

Results

Immediately following bicycle helmet legislation, the rate of bicycle fatalities per 1 000 000 population reduced by 46% relative to the pre-legislation trend [95% confidence interval (CI): 31, 58]. For the period 1990–2016, we estimate 1332 fewer cycling fatalities (95% CI: 1201, 1463) or an average of 49.4 per year (95% CI: 44.5, 54.2). Reductions were also observed for pedestrian fatalities; however, bicycle fatalities declined by 36% relative to pedestrian fatalities (95% CI: 12, 54).

Conclusions

In the absence of robust evidence showing a decline in cycling exposure following helmet legislation or other confounding factors, the reduction in Australian bicycle-related fatality appears to be primarily due to increased helmet use and not other factors.

Risk compensation? The relationship between helmet use and cycling speed under naturalistic conditions

INTRODUCTION

An argument against mandatory helmet use is based on the idea of risk compensation, which means that cyclists might ride faster when wearing a helmet (Lardelli-Claret et al., 2003). However, questionnaire and experimental studies were unable to find evidence for this assumption (Fyhri et al., 2012; Fyhri & Philipps, 2013). Simultaneously, other factors with a potential role in helmet use and cycling speed, such as trip length and rider characteristics have been neglected in such considerations. The goal of the analysis presented in this paper was therefore to investigate the relationship between helmet use and cycling speed under naturalistic conditions while taking characteristics of cyclists and bicycles into account.

METHOD

As part of a naturalistic cycling study, we equipped the bicycles of conventional and e-bike riders with data acquisition systems to record speed and trip distance. It included two cameras (one for the face of the participant, another one for the forward scenery). For the analysis presented in this paper, we used the data of 76 participants (28 conventional bicycles, 48 e-bikes).

RESULTS

In total, participants used their helmet for 56% of all trips. Helmets were used more frequently for longer trips. A linear mixed model, in which trip length, helmet use, bicycle type, age, and gender were used as predictors showed that helmet use did not play a significant role for cycling speed. Instead, all other factors that were analyzed, with the exception of gender, had a significant relationship to cycling speed.

DISCUSSION

The assumption of risk compensation as a result of the use of a helmet could not be confirmed. Instead, the findings seem to support the suggestion that cyclists who undertake trips at potentially higher speed levels are aware of their increased risk, and actively try to reduce it through the use of a helmet.

Recommend or mandate? A systematic review and meta-analysis of the effects of mandatory bicycle helmet legislation

If all cyclistswere wearing helmets, significant numbers of head injuries might theoretically be prevented. Mandatory bicycle helmet legislation increases helmet use but is a controversial measure. Results from 21 studies of the effects of mandatory bicycle helmet legislation on injuries among crash involved cyclists were investigated by means of meta-analysis and the effects of several potential biases were investigated. The summary effect of mandatory bicycle helmet legislation for all cyclists on head injuries is a statistically significant reduction by 20% (95% confidence interval [-27; -13]). Larger effects were found for serious head injury (-55%; 95% confidence interval; [-78; -8]). Among children, larger effects were found when legislation applies to all cyclists than when it applies to children only. There is no clear indication of the results being affected by publication bias. Publication bias may exist, but any existing biases seem to more or less outweigh each other. Results from meta-analysis do not indicate that the results are systematically affected by a lack of control for time trend bias, choice of comparison group or study design (before-after vs. case control). Summary effects may be somewhat overestimated because of a lack of control for potential confounding variables in some of the studies. However, such a bias, if it exists, is not likely to be large. Empirical evidence for the hypotheses that mandatory bicycle helmet legislation deters people from cycling and that helmet wearing leads to behavioral adaptation is mixed. In summary, mandatory bicycle helmet legislation can be expected to reduce head injury among crash involved cyclists. Some adverse effects may occur, but will not necessarily be large or long-lasting. People who may be deterred from cycling, are among those with the highest injury risk and the smallest health effects from cycling. If the overall goal is to improve safety for all cyclists and to increase cycling, mandatory bicycle helmet legislation should be supplemented by other measures, especially improved bicycle infrastructure.

Protective effects of helmets on bicycle-related injuries in elderly individuals

OBJECTIVE

The increasing frequency of bicycle-related injuries is due to the growing elderly population and their increasing physical activity. This study aimed to compare the protective effects of helmets on bicycle-related injuries in elderly individuals compared with those in younger adults.

METHODS

Data from the Korean emergency department-based Injury In-depth Surveillance database from eight emergency departments during 2011-2016 were retrospectively analysed. The subjects sustained injuries while riding bicycles. Cases with unknown clinical outcomes were excluded. Covariates included mechanism, place and time of injury. The primary outcome was traumatic brain injury (TBI) incidence, and the secondary outcomes were in-hospital mortality and severe trauma. The effects of helmets on these outcomes were analysed and differences in effects were determined using logistic regression analysis. Subsequently, the differences in the effects of helmets use between age groups were examined by using interaction analysis RESULTS: Of 7181 adults, 1253 were aged >65 years. The injury incidents showed a bimodal pattern with peaks around ages 20 and 50 years. Meanwhile, the helmet-wearing rate showed a unimodal pattern with its peak at age 35-40 years; it decreased consistently with age. By multivariate analysis, helmet-wearing was associated with a reduced TBI incidence (OR 0.76; 95% CI 0.57 to 0.99) and severe trauma (OR 0.78; 95% CI 0.65 to 0.93). The effects of helmets increased in elderly individuals (TBI (p=0.022) and severe trauma (p=0.024)).

CONCLUSION

The protective effects of helmets on bicycle-related injuries are greater for elderly individuals, thus reducing TBI incidence.

Fatal Cervical Spine Injury Following a Bicycle Crash

Spinal injury following direct loading of the head and neck is a rare sequel of bicycle crashes. Fatal head injuries following bicycle crashes have been described in great detail and safety measures such as bicycle helmets have been developed accordingly. Less frequently, however, potentially severe cervical spine injuries have been described. We present the case of a middle-aged female who sustained an ultimately fatal cervical spine injury following a collision with a car whilst biking wearing a helmet. We discuss the literature regarding the protective effects of bicycle helmets, the relevance to cervical spine injury and legislation on mandatory use of helmets for injury prevention.