Bicycling injury hospitalisation rates in Canadian jurisdictions: analyses examining associations with helmet legislation and mode share

Risk of bicycle collisions and 'safety in numbers': a natural experiment using the local introduction of e-scooters in England

BACKGROUND

Ecological studies hypothesise a 'safety in numbers' (SiN) effect whereby road safety for bicycles and other micromobility users improves as their numbers increase, due to behavioural changes of motorists. Causal interpretation of these studies is difficult due to confounding and reverse causation. The introduction of electric scooter (e-scooter) rental schemes in selected districts in England meant an increase in micromobility users in these areas, which presented an opportunity to test the SiN hypothesis using a natural experiment.

METHODS

Time-series analysis of police data on road collisions in local authorities (LAs) in Great Britain, 2015-2023. Random-effects Poisson regression time-series models compared collision rates in LA districts with an e-scooter trial (n=41) versus matched control districts (n=41). Primary outcomes were all road collisions and bicycle collisions. Models adjusted for time; seasonality; baseline collision rate; COVID-19 period; and preintervention/postintervention period (proxied by intervention group/COVID-19 period interaction).

RESULTS

The rate of bicycle collisions reduced following the introduction of the schemes, compared with control districts (incidence rate ratio (IRR) 0.78, 95% CI 0.68 to 0.89 during peak COVID-19; IRR 0.87, 95% CI 0.77 to 0.99 in the post-COVID-19 period). This effect was specific to bicycle collisions and strongest in the subgroup of serious/fatal collisions.

CONCLUSIONS

Findings suggest that the increase of a new and sustainable mode of transport, e-scooters, may have reduced bicycle collisions. This could have far-reaching benefits including reduced injuries, safer environments, and public health and environmental benefits if more people choose bicycles and micromobility over car transport. Findings should be verified in further work.

Socioeconomic milieu and culture: Forcing factors and the Most fundamental determinant of health

We introduce the concept of forcing factors, analogous to risk factors for population-wide health outcomes, that are attributes of the physical, social, legal, economic, or cultural environment that are common to all people in an identified population and that promote or inhibit particular outcomes of health, wellness, and well-being. Examples include laws governing food or tobacco marketing, the built environment, and climate change. Culture also functions as a forcing factor of health outcomes. In contrast to past explanations of adverse health outcomes that have relied on cultural attributes of a specific sub-population, we draw on work of John McKinlay to make the point that it is the shared culture of a country or a region that influences health outcomes. Culture itself operates in a particular cultural context.

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.

Predictors of Mortality in Bicycle-Related Trauma: An Eight-Year Experience in a Level One Trauma Center

Background: Bicycle-related trauma has increased during the last decades, mainly due to the antipollution environmental policies. This study investigates the outcome of bicycle-related trauma in our level-one trauma center over a period of eight years. Methods: Data from 446 consecutive bicycle-related trauma patients admitted to our trauma center from 2011 to 2019 were selected and retrospectively analyzed. The sample was divided into three age groups: <18 years, 18−54 years, and ≥55 years. Mortality rates were obtained for the overall population and patients with an Injury Severity Score (ISS) ≥ 25. Month and seasonal patients’ distribution was described to provide an epidemiological overview of bike-related trauma over the years. Results: Patients ≥ 55 years showed a lower pre-hospital and in-hospital GCS (p ≤ 0.001), higher levels of lactates (p < 0.019) and higher ISS (p ≤ 0.001), probability of death (p ≤ 0.001), and overall mortality (p ≤ 0.001). The head and chest Abbreviated Injury Scale (AIS) ≥ 3 injuries were predictors of mortality, especially in patients over 55 years (p < 0.010). Bicycle-related trauma was more frequent during the summer (34%), particularly in July and August. Conclusions: Age over 55 years old, head and chest injuries, and an ISS > 25 were independent predictors of mortality.

Estimating walking and bicycling in Canada and their road collision fatality risks: The need for a national household travel survey

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Canadian Community Health Survey captures more bicycling/walking than the census.

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Across data sources, walking more common among women than men.

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Men had higher risk of a fatality than women for bicycling and walking.

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Both data sources have key limitations for measuring bicycling and walking.

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Implementing a national household travel survey should be a priority in Canada.

Canada does not conduct a national household travel survey, resulting in a data gap on walking and bicycling. These data are key to surveillance of physical activity and health, as well as in epidemiological injury risk calculations. This study explored the use of available national data sources, the Canadian census and the Canadian Community Health Survey (CCHS), to tally walking and bicycling and examine trends in fatality risk. Estimates of the percentage and number of Canadians walking or bicycling to work were calculated for 1996–2016 using the census. The CCHS was used to estimate the number and proportion of Canadians walking or bicycling for leisure (2000–2014) and to work or school (2008–2014). We combine these data with National Collision Database data on the number of pedestrian and bicyclist fatalities (1999–2017) and compare trends in fatality risk over time using each dataset. Across all data sources, walking was more common among women, while bicycling was more common among men. Men were at higher fatality risk than women. These results should be interpreted with caution given limitations this study identifies in census and CCHS data, including narrow definitions for bicycling behaviour, lack of detail regarding amount of use, and inconsistency of questions asked over time. A national household travel survey should be a priority for public health purposes in Canada.

Severity and predictors of head injury due to bicycle accidents in Western Australia

BACKGROUND

Head and face injuries are the second most frequently reported injuries among bicyclists. Recently, helmet usage has increased, and in some countries, helmet laws have been introduced. However, subsequent changes in the incidence and severity of traumatic brain injury (TBI) are unknown, and data on neurosurgical interventions are lacking. Therefore, we analyzed a cohort of bicyclists with TBI, in a state with an enforced helmet law, and compared our results with the available literature.

METHODS

Patient data of bicycle accidents that occurred between January 2008 and January 2015 were extracted from the state trauma registry, and the corresponding patient files and CT scans were comprehensively reviewed.

RESULTS

Of the 1019 patients admitted due to bicycle accidents, 187 patients suffered from TBI. Most cases were mild; however, 72 involved intracranial hemorrhages. Of the TBI patients, 113 were wearing helmets. CT scans were performed on 168 TBI patients, 120 of whom had a Rotterdam CT score of 1, with no difference between helmeted and non-helmeted patients. Open head injury (p < 0.05) and epidural hematomas were significantly less frequent among helmet wearers (p = 0.03). Ten patients required surgery; helmet use and neurosurgical involvement were not significantly correlated.

CONCLUSIONS

Patients who wore helmets were significantly less likely to suffer from epidural hematomas and open head injuries. While TBI severity was not significantly different between helmeted and non-helmeted bicyclists, the overall occurrence of TBI and moderate to severe TBI among all admissions was lower than that seen in comparable studies from countries without helmet laws.

Bicycle Helmets and Bicycle-Related Traumatic Brain Injury in the Netherlands

The aim of this study was to determine the association between bicycle helmet use in adults (16 years and older) and traumatic brain injury (TBI) in emergency departments (EDs) in the Netherlands.The conducted research was a retrospective case-control study in patients aged 16 years and older who sustained a bicycle accident and therefore visited the EDs of participating hospitals throughout 2016. Cases were patients with TBI; controls were patients without TBI but with other trauma. Exposure was defined as helmet wearing during the accident. In total, 2133 patients were included in the study, 361 case patients and 1772 controls. Within the TBI group (cases) 3.9% of patients wore a helmet compared with 7.7% of patients in the control (non-head injury) group (odds ratio [OR] 0.49, 95% confidence interval [CI]: 0.28-0.86). No difference in helmet wearing was observed in patients who sustained accidents that involved motorized vehicles (OR 0.91; 95% CI: 0.29-2.83). In conclusion, adult patients (≥16 years of age) with TBI had a significantly lower odds of wearing a bicycle helmet than adult patients with other trauma, adding more evidence that wearing a bicycle helmet effectively protects against TBI.

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.

Bicycling-related concussions leading to postconcussion syndrome in adults

Background

Concussions among adult bicyclists are common, but little is known about the long-term effects of the consequences of these concussions such as postconcussion syndrome (PCS) including its occurrence, clinical features and recovery potential. Indeed, our study is the first to examine PCS due to bicycling in any age group.

Objectives

We examined patient demographics, concussion mechanisms and persistent symptoms as factors leading to PCS in adults and the potential for recovery.

Methods

We conducted a retrospective chart review of 28 patients age 18 or older who sustained a concussion while bicycling and were referred to the Canadian Concussion Centre for management of PCS.

Results

Eighteen patients (64.3%) fell from their bicycles due to loss of control, attempts to avoid a crash or collision with an object. Eight patients (28.6%) were struck by a motor vehicle, and two patients (7.1%) were injured by collision with another bicycle. The mean duration of PCS was 23.7 months and at the time of the last follow-up, 23 (82.1%) patients had failed to recover completely. Patients with one or more previous concussions had a significantly longer duration of PCS (p=0.042). Bicycling concussions resulted in a greater mean duration of PCS (23.7 months) than a comparison group of patients with PCS due to collision sports (16.1 months) (p=0.07).

Conclusion

Adults who sustain bicycling-related concussions and develop PCS often have long-lasting symptoms; greater attention should be given to prevention strategies such as improved bicycling infrastructure and safer bicycling practices to reduce concussions in adult bicyclists.

Comparison of the Incidence and Severity of Traumatic Brain Injury Caused by Electrical Bicycle and Bicycle Accidents-A Retrospective Cohort Study From a Swiss Level I Trauma Center

BACKGROUND

Electrical bicycles (E-bikes) allow people of all ages to ride at high speeds but have an inherent risk of traumatic brain injury (TBI). Their sales have increased tremendously in recent years.

METHODS

We performed a retrospective cohort study to compare the incidence and severity of TBI in E-bikers and conventional bicyclists. We included patients at a Swiss level 1 trauma center admitted from 2010 to 2015. The primary outcome was the association between TBI and the bicycle type. The secondary outcome was the association between helmet use and TBI severity.

RESULTS

Of 557 patients injured riding an E-bike (n = 73) or a bicycle (n = 484), 60% sustained a TBI, most of which were mild (Glasgow coma scale [GCS] score, 13-15; E-bike, 78%; bicycle, 88%). TBI was more often moderate (GCS score, 9-12) or severe (GCS score, 3-8) in E-bikers than in bicyclists (P = 0.04). Intracranial hemorrhage, traumatic subarachnoid hemorrhage, and subdural hematoma occurred significantly more often in E-bikers than in bicyclists (P < 0.05). Neurosurgical intervention was necessary for 5 E-bikers (7%) and 25 (5%) bicyclists (P = 0.15). Wearing a helmet correlated with a lower risk of neurosurgical intervention in bicyclists (odds ratio [OR], 0.21; 95% confidence interval [CI], 0.06-0.73; P = 0.01) and a lower risk of calvarial fractures in both bicyclists (OR, 0.16; 95% CI, 0.06-0.42; P < 0.01) and E-bikers (OR, 0.21; 95% CI, 0.05-0.84; P = 0.03).

CONCLUSIONS

E-bikers had a significantly greater risk of moderate to severe TBI compared with bicyclists. Helmet use was associated with decreased odds of severe TBI in bicyclists and a tendency toward a more favorable outcome for E-bikers.

Impact of wearing a helmet on the risk of hospitalization and intracranial haemorrhage after a sports injury

BACKGROUND

Despite their reported protective effect against the occurrence of head injuries, helmets are still used inconsistently in sports in which they are optional. We aimed to assess the impact of helmet use on the risk of hospitalization and intracranial haemorrhage for trauma occurring during sport activities.

METHODS

Retrospective cohort of all patients who presented themselves, over an 18-month period, at the emergency department of a tertiary trauma centre for an injury sustained in a sport or leisure activity where the use of a helmet is optional. Impact of helmet use was assessed using multivariable regression analyses (relative risks, RR).

RESULTS

Among the 1,022 patients included in the study, half were cyclists and 40% were skiers or snowboarders. A total of 40 % of patients wore a helmet at the time of injury, 18% had a head injury, 16% were hospitalized and 13% of patients with a head injury had an intracranial haemorrhage. Among all patients, no association was observed between hospital admission and helmet use. However, helmet use in patients with a head injury was associated with significant reductions in the risks of hospitalization (RR 0.41 [95% CI: 0.22-0.76]) and intracranial haemorrhage (RR 0.28 [95% CI: 0.11-0.71]).

CONCLUSIONS

Results suggest that, in recreational athletes who sustain a head injury, helmet use is associated with a reduced risk of hospitalization (all sports) and intracranial haemorrhage (cyclists).

Long-Term Effects of Education and Legislation Enforcement on All-Age Bicycle Helmet Use: A Longitudinal Study

Bicycle-related injuries are a leading cause of child and youth hospitalizations in Canada. The use of helmets while bicycling reduces the risk of brain injuries. This study investigated the long-term effect of legislation coupled with enforcement to improve helmet use rates. We conducted a longitudinal observational study of helmet use at 9, 11, and 14 years after bicycle helmet legislation was enacted. Data were compared to baseline observations collected after legislation was passed in 1997. A comprehensive enforcement and educational diversion program, Operation Headway-Noggin Knowledge (OP-NK), was developed and implemented in partnership with regional police during the study period. Helmet use was sustained throughout the post-legislation period, from 75.3 % in the year legislation was enacted to 94.2 % 14 years post-legislation. The increase in helmet use was seen among all age groups and genders. Helmet legislation was not associated with changes in bicycle ridership over the study years. OP-NK was associated with improved enforcement efforts as evidenced by the number of tickets issued to noncompliant bicycle riders. This observational study spans a 16-year study period extending from pre-legislation to 14 years post all-age bicycle helmet legislation. Our study results demonstrate that a comprehensive approach that couples education and awareness with ongoing enforcement of helmet legislation is associated with long-term sustained helmet use rates. The diversion program described herein is listed among best practices by the Public Health Agency of Canada.

Comparing ICD-10 external cause codes for pedal cyclists with self-reported crash details

Accurate coding of injury event information is critical in developing targeted injury prevention strategies. However, little is known about the validity of the most universally used coding system, the International Classification of Diseases (ICD-10), in characterising crash counterparts in pedal cycling events. This study aimed to determine the agreement between hospital-coded ICD-10-AM (Australian modification) external cause codes with self-reported crash characteristics in a sample of pedal cyclists admitted to hospital following bicycle crashes. Interview responses from 141 injured cyclists were mapped to a single ICD-10-AM external cause code for comparison with ICD-10-AM external cause codes from hospital administrative data. The percentage of agreement was 77.3% with a κ value of 0.68 (95% CI 0.61 to 0.77), indicating substantial agreement. Nevertheless, studies reliant on ICD-10 codes from administrative data should consider the 23% level of disagreement when characterising crash counterparts in cycling crashes.

Emergency physicians as human billboards for injury prevention: a randomized controlled trial

OBJECTIVES

The objective of this study was to evaluate the impact of a novel injury prevention intervention designed to prompt patients to initiate an injury prevention discussion with the ED physician, thus enabling injury prevention counselling and increasing bicycle helmet use among patients.

METHODS

A repeated measures 2 x 3 randomized controlled trial design was used. Fourteen emergency physicians were observed for two shifts each between June and August 2013. Each pair of shifts was randomized to either an injury prevention shift, during which the emergency physician would wear a customized scrub top, or a control shift. The outcomes of interest were physician time spent discussing injury prevention, current helmet use, and self-reported change in helmet use rates at one year. Logistic regression analyses were used to examine the impact of the intervention.

RESULTS

The average time spent on injury prevention for all patients was 3.3 seconds. For those patients who actually received counselling, the average time spent was 17.0 seconds. The scrub top intervention did not significantly change helmet use rates at one year. The intervention also had no significant impact on patient decisions to change or reinforcement of helmet use.

CONCLUSIONS

Our study showed that the intervention did not increase physician injury prevention counselling or self-reported bicycle helmet use rates among patients. Given the study limitations, replication and extension of the intervention is warranted.

Helmet Laws, Helmet Use, and Bicycle Ridership

PURPOSE

To assess bicycle helmet laws' effect on helmet and bicycle use among U.S. high school students in urban jurisdictions.

METHODS

Log-binomial models were fit to Youth Risk Behavior Survey data from five jurisdictions. Adjusted helmet and bicycle use proportions were calculated with post-regression marginal effects. Difference-in-differences were estimated, comparing intervention to concurrent controls. A placebo outcome was used to falsify possible confounding or selection effects.

RESULTS

In San Diego and Dallas, helmet use increase increased 10.6 (95% confidence interval [CI] 6.5 to 14.7, p < .001) and 8.1 (95% CI 4.3 to 12.0, p < .001) percentage points more than out-of-jurisdiction controls. Increases in Florida counties were 5.0 (95% CI 1.8 to 8.2, p = .003) and 4.0 (95% CI -.7 to 8.8, p = .098) points against age-based and out-of-jurisdiction controls, respectively. Bicycle use fell 5.5 points in both San Diego (95% CI -9.8 to -1.1, p = .015) and the Florida counties (95% CI -11.5 to .5, p = .075) against out-of-jurisdiction controls, but other comparisons had no significant changes. The placebo outcome never changed significantly.

CONCLUSIONS

Laws increased helmet use in all jurisdictions, with limited evidence of reduced cycling. Although sound health policy, laws should be coupled with physical activity promotion.