Incidence, severity, and outcomes of brain injuries involving bicycles

Development and Validation of Indicators for Population Injury Surveillance in Hong Kong: Development and Usability Study

BACKGROUND

Injury is an increasingly pressing global health issue. An effective surveillance system is required to monitor the trends and burden of injuries.

OBJECTIVE

This study aimed to identify a set of valid and context-specific injury indicators to facilitate the establishment of an injury surveillance program in Hong Kong.

METHODS

This development of indicators adopted a multiphased modified Delphi research design. A literature search was conducted on academic databases using injury-related search terms in various combinations. A list of potential indicators was sent to a panel of experts from various backgrounds to rate the validity and context-specificity of these indicators. Local hospital data on the selected core indicators were used to examine their applicability in the context of Hong Kong.

RESULTS

We reviewed 142 articles and identified 55 indicators, which were classified into 4 domains. On the basis of the ratings by the expert panel, 13 indicators were selected as core indicators because of their good validity and high relevance to the local context. Among these indicators, 10 were from the construct of health care service use, and 3 were from the construct of postdischarge outcomes. Regression analyses of local hospitalization data showed that the Hong Kong Safe Community certification status had no association with 5 core indicators (admission to intensive care unit, mortality rate, length of intensive care unit stay, need for a rehabilitation facility, and long-term behavioral and emotional outcomes), negative associations with 4 core indicators (operative intervention, infection rate, length of hospitalization, and disability-adjusted life years), and positive associations with the remaining 4 core indicators (attendance to accident and emergency department, discharge rate, suicide rate, and hospitalization rate after attending the accident and emergency department). These results confirmed the validity of the selected core indicators for the quantification of injury burden and evaluation of injury-related services, although some indicators may better measure the consequences of severe injuries.

CONCLUSIONS

This study developed a set of injury outcome indicators that would be useful for monitoring injury trends and burdens in Hong Kong.

Evaluating the impact of cycle helmet use on severe traumatic brain injury and death in a national cohort of over 11000 pedal cyclists: a retrospective study from the NHS England Trauma Audit and Research Network dataset

OBJECTIVES

In the last 10 years there has been a significant increase in cycle traffic in the UK, with an associated increase in the overall number of cycling injuries. Despite this, and the significant media, political and public health debate into this issue, there remains an absence of studies from the UK assessing the impact of helmet use on rates of serious injury presenting to the National Health Service (NHS) in cyclists.

SETTING

The NHS England Trauma Audit and Research Network (TARN) Database was interrogated to identify all adult (≥16 years) patients presenting to hospital with cycling-related major injuries, during a period from 14 March 2012 to 30 September 2017 (the last date for which a validated dataset was available).

PARTICIPANTS

11 patients met inclusion criteria. Data on the use of cycling helmets were available in 6621 patients.

OUTCOME MEASURES

TARN injury descriptors were used to compare patterns of injury, care and mortality in helmeted versus non-helmeted cohorts.

RESULTS

Data on cycle helmet use were available for 6621 of the 11 192 cycle-related injuries entered onto the TARN Database in the 66 months of this study (93 excluded as not pedal cyclists). There was a significantly higher crude 30-day mortality in un-helmeted cyclists 5.6% (4.8%-6.6%) versus helmeted cyclists 1.8% (1.4%-2.2%) (p<0.001). Cycle helmet use was also associated with a reduction in severe traumatic brain injury (TBI) 19.1% (780, 18.0%-20.4%) versus 47.6% (1211, 45.6%-49.5%) (p<0.001), intensive care unit requirement 19.6% (797, 18.4%-20.8%) versus 27.1% (691, 25.4%-28.9%) (p<0.001) and neurosurgical intervention 2.5% (103, 2.1%-3.1%) versus 8.5% (217, 7.5%-9.7%) (p<0.001). There was a statistically significant increase in chest, spinal, upper and lower limb injury in the helmeted group in comparison to the un-helmeted group (all p<0.001), though in a subsequent analysis of these anatomical injury patterns, those cyclists wearing helmets were still found to have lower rates of TBI. In reviewing TARN injury codes for specific TBI and facial injuries, there was a highly significant decrease in rates of impact injury between cyclists wearing helmets and those not.

CONCLUSIONS

This study suggests that there is a significant correlation between use of cycle helmets and reduction in adjusted mortality and morbidity associated with TBI and facial injury.

Epidemiology and Risk Factors for Bicycle-Related Severe Head Injury: A Single Center Experience

OBJECTIVE

Head injury is the main cause of death and severe disability in bicycle-related injuries. The purpose of this study was to compare the demographic characteristics and injury mechanisms of bicycle-related head injuries according to the severity and outcome and determine the main risk factors and common types of accompanying injuries.

METHODS

A total of 205 patients who were admitted to the neurosurgery department of our hospital for bicycle-related head injuries between 2007 and 2016 were analyzed. We categorized the patients into two groups according to severity and outcome of head injury, and then identified the differences in age, sex, and cause of injury between the two groups.

RESULTS

Collisions with a motor vehicle increased the risk of severe head injury (p=0.011), resulted in poor outcomes (Glasgow Outcome Scale [GOS] ≤3; p=0.022), and caused more accompanying chest/abdominal (p<0.001) and pelvic/lower extremity injuries (p=0.001) than other mechanisms. Older age and high grade of head injury severity resulted in poor outcomes (p=0.028 and p<0.001, respectively), and caused more accompanying chest/abdominal injuries (p<0.032 and p<0.001, respectively) compared with younger age and low grade of head injury severity.

CONCLUSION

In bicycle-related head injuries, collision with motor vehicle is one of the most important risk factor for high grade of head injury severity and outcome. In addition, bicycle-related head injuries are often accompanied by injuries of other parts of the body.

Cyclists fatalities: Forensic remarks regarding 335 cases

A retrospective study was carried out on post-mortem examination data regarding 335 cyclists involved in fatal accidents along the period 1983-2012. The following variables were considered: temporal data (year, month, day of the week and hour of the day), circumstances of the accident, vehicles involved, victims' features (sex, age), pathological and toxicological findings, cause of death. Most victims were male (77.62%), with a mean age of 58 years. In most cases vehicles other than only bicycles were involved, more frequently cars, followed by heavy motor vehicles. Head was the most frequently body region involved in lethal injuries (65.37%); low extremities were the body district most frequently involved in non-lethal injuries (63.9%). This study confirmed the importance of using helmet; head protection should be a priority for bikers.

Incidence and costs of bicycle-related traumatic brain injuries in the Netherlands

The main cause of death and serious disability in bicycle accidents is traumatic brain injury (TBI). The aim of this population-based study was to assess the incidence and costs of bicycle-related TBI across various age groups, and in comparison to all bicycle-related injuries, to identify main risk groups for the development of preventive strategies. Data from the National Injury Surveillance System and National Medical Registration were used for all patients with bicycle-related injuries and TBI who visited a Dutch emergency department (ED) between 1998 and 2012. Demographics and national, weighted estimates of injury mechanism, injury severity and costs were analysed per age group. Direct healthcare costs and indirect costs were determined using the incidence-based Dutch Burden of Injury Model. Between 1998 and 2012, the incidence of ED treatments due to bicycle-related TBI strongly increased with 54%, to 43 per 100,000 persons in 2012. However, the incidence of all bicycle-related injuries remained stable, from 444 in 1998 to 456/100,000 in 2012. Incidence of hospital admission increased in both TBI (92%) and all injuries from cycling (71%). Highest increase in incidence of both ED treatments and hospital admissions was seen in adults aged 55+. The injury rate of TBI per kilometre travelled increased (44%) except in children, but decreased (-4%) for all injuries, showing a strong decrease in children (-36%) but an increase in men aged 25+, and women aged 15+. Total costs of bicycle-related TBI were €74.5 million annually. Although bicycle-related TBI accounted for 9% of the incidence of all ED treatments due to cycling, it accounted for 18% of the total costs due to all bicycle-related injuries (€410.7 million). Children and adolescents (aged 0-24) had highest incidence of ED treatments due to bicycle-related injuries. Men in the working population (aged 15-64) had highest indirect costs following injuries from cycling, including TBI. Older cyclists (aged 55+) were identified as main risk group for TBI, as they had highest ED attendance, injury rate, injury severity, admission to hospital or intensive care unit, and costs. Incidence of ED treatments due to cycling are high and often involve TBI, imposing a high burden on individuals and society. Older cyclists aged 55+ were identified as main risk group for TBI to be targeted in preventive strategies, due to their high risk for (serious) injuries and ever-increasing share of ED visits and hospital admissions.

Societal cost of traumatic brain injury: A comparison of cost-of-injuries related to biking with and without helmet use

OBJECTIVE

The goal of this study is to determine if a difference in societal costs exists from traumatic brain injuries (TBI) in patients who wear helmets compared to non-wearers.

METHODS

This is a retrospective cost-of-injury study of 128 patients admitted to the Montreal General Hospital (MGH) following a TBI that occurred while cycling between 2007-2011. Information was collected from Quebec Trauma Registry. The independent variables collected were socio-demographic, helmet status, clinical and neurological patient information. The dependent variables evaluated societal costs.

RESULTS

The median costs of hospitalization were significantly higher (p = 0.037) in the no helmet group ($7246.67 vs. $4328.17). No differences in costs were found for inpatient rehabilitation (p = 0.525), outpatient rehabilitation (p = 0.192), loss of productivity (p = 0.108) or death (p = 1.000). Overall, the differences in total societal costs between the helmet and no helmet group were not significantly different (p = 0.065). However, the median total costs for patients with isolated TBI in the non-helmet group ($22, 232.82) was significantly higher (p = 0.045) compared to the helmet group ($13, 920.15).

CONCLUSION

Cyclists sustaining TBIs who did not wear helmets in this study were found to cost society nearly double that of helmeted cyclists.

Regarding the fitness to ride a bicycle under the acute influence of alcohol

To determine the threshold for the absolute inability to ride a bicycle, practical cycling tests and medical examinations at different blood alcohol concentrations were performed. Special attention was given to additional medical examinations, reaction tests and alcohol consumption under real-life conditions. Seventy-eight test subjects were included in the trials (37 females, 41 males). Five test subjects participated twice; thus, there were a total of 83 evaluable trials. Alcohol-related deficits were already identifiable at very low BACs. A significant increase in gross motoric disturbances compared to the soberness state did not regularly occur until a BAC of at least 0.8 g/kg was reached. At the BAC of 1.4 g/kg and above, no test subjects were able to achieve or surpass their sober driving results. Isolated highly alcoholised test subjects rode the bike in a manner that was not conspicuously different than the other sober test persons. Contrary to the assumptions of current German legal practise, it cannot be stated that all people are 'absolutely impaired' to the point of being incapable of riding bicycle at BACs of at least 1.6 g/kg.

Performance analysis of the protective effects of bicycle helmets during impact and crush tests in pediatric skull models

OBJECT

Bicycle accidents are a very important cause of clinically important traumatic brain injury (TBI) in children. One factor that has been shown to mitigate the severity of lesions associated with TBI in such scenarios is the proper use of a helmet. The object of this study was to test and evaluate the protection afforded by a children's bicycle helmet to human cadaver skulls with a child's anthropometry in both "impact" and "crushing" situations.

METHODS

The authors tested human skulls with and without bicycle helmets in drop tests in a monorail-guided free-fall impact apparatus from heights of 6 to 48 in onto a flat steel anvil. Unhelmeted skulls were dropped at 6 in, with progressive height increases until failure (fracture). The maximum resultant acceleration rates experienced by helmeted and unhelmeted skulls on impact were recorded by an accelerometer attached to the skulls. In addition, compressive forces were applied to both helmeted and unhelmeted skulls in progressive amounts. The tolerance in each circumstance was recorded and compared between the two groups.

RESULTS

Helmets conferred up to an 87% reduction in so-called mean maximum resultant acceleration over unhelmeted skulls. In compression testing, helmeted skulls were unable to be crushed in the compression fixture up to 470 pound-force (approximately 230 kgf), whereas both skull and helmet alone failed in testing.

CONCLUSIONS

Children's bicycle helmets provide measurable protection in terms of attenuating the acceleration experienced by a skull on the introduction of an impact force. Moreover, such helmets have the durability to mitigate the effects of a more rare but catastrophic direct compressive force. Therefore, the use of bicycle helmets is an important preventive tool to reduce the incidence of severe associated TBI in children as well as to minimize the morbidity of its neurological consequences.

The changing face of mild head injury: temporal trends and patterns in adolescents and adults from 1997 to 2008

OBJECTIVE

To explore the temporal trend of incidence, causes of injury and main characteristics of adolescent and adult subjects with mild head injury (MHI).

DESIGN

This study had a retrospective design.

SETTING

The study was conducted in a longitudinal database of an Italian Emergency Department (ED).

PARTICIPANTS

The study comprised 19124 consecutive subjects who visited and were managed within 24 h from the event, according to a predefined protocol for MHI from 1997 to 2008.

MAIN OUTCOME MEASURES

Incidence, demography, cause of injury and characteristics of any post-traumatic intracranial lesion within 7 days from MHI.

RESULTS

The number of subjects with MHI decreased from 2019 per year (1997-1999) to 1232 per year (2006-2008; P for linear trend <0.001), without differences in the total number of subjects visited in the ED. The decrease was observed in all age-decades, in particular, in subjects in the age ranges of 20-29 and 30-39 years. Over time, the age of subjects with MHI lost a bimodal distribution, and the mean age increased from 43 (25-69) years (median (interquartile range)) in 1997-1999 to 56 (33-78) years in 2006-2008 (P<0.001). The prevalence of falls increased from 36.5% to 55.0%, whereas crashes fell from 53.2% to 31.9%. The incidence of subdural haematoma (SDH) and epidural haematoma (EDH) did not change over time, whereas traumatic subarachnoid haemorrhage (t-SAH) and intra-cerebral haematoma/brain contusion (ICH) increased (from 0.7% to 1.9% and from 2.5% to 3.2%; P for trend: <0.001 for both.

CONCLUSIONS

The incidence and the clinical characteristics of MHI subjects are rapidly changing in our setting. These data need to be considered in defining the effectiveness of preventive measures and deciding resource allocation.

Bicycle helmet legislation: can we reach a consensus?

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.

Pediatric traumatic brain injury: past, present and future

Traumatic brain injury (TBI) is the leading cause of death and disability in children. Evidence-based guidelines for the management of this population are available; however, the data highlight significant deficiencies with few treatment standards or guidelines. Considering the limited availability of resources, it is necessary to define realistic goals. Attention should be given to injury prevention, developing standardized pediatric admission and outcome evaluations, increasing the utility and spectrum of physiological and biochemical testing, and defining the evolving role of imaging in TBI.

Does promoting bicycle‐helmet wearing reduce childhood head injuries?

The objectives of the study are to assess the impact of a community‐based bicycle‐helmet program aimed at children aged 5–12 years (about 140,000). A quasi‐experimental design, including a control group, was used. Sex‐ and age‐group‐based changes in the risk of bicycle‐related head injury leading to hospitalisation were measured, using rate ratios. Compared with the pre‐program period, significant risk reductions were observed during the post‐program period among both boys (RR = 0.56, 95 per cent CI = 0.40, 0.77) and girls (RR = 0.52, 95 per cent CI = 0.33, 0.82), and among both younger (RR = 0.46, 95 per cent CI = 0.31, 0.68) and older (RR = 0.63, 95 per cent CI = 0.44, 0.89) children. A significant reduction was also observable during the program phase among the groups most at risk, i.e. boys (RR = 0.94, 95 per cent CI = 0.66, 1.35) and younger children (RR = 1.07, 95 per cent CI = 0.70, 1.63). The population‐based educational program significantly decreased the risk of head injuries among boys and girls despite observable differences in the voluntary adoption rate of bicycle‐helmet wearing. The impact was more pronounced among younger children.

Bicycle-related head injury: a study of 86 cases

Within the framework of a bicycle helmet research program, we have set up a database of bicycle accident victims, containing both accident and clinical data. The database consists of a consecutive series of 86 victims of bicycle accidents who underwent a neurosurgical intervention in our hospital between 1990 and 2000. Data were obtained from police files, medical records, computed tomography head scans and a patient questionnaire. In only three victims, the wearing of a helmet was documented. In this study, the head injuries are analysed and the relation between the different types of head injuries and outcome is assessed. Forty-four accidents were collisions with a motor vehicle and 42 accidents were falls. Most impacts occurred at the side (57%) or at the front (27%) of the head. The most frequent injuries were skull fractures (86%) and cerebral contusions (73%). Age was negatively correlated with outcome (P = 0.0002 ) and positively correlated with the number (P = 0.00002) and volume (P = 0.00005) of contusions and the presence of subdural haematomas (P = 0.000001). The injuries with the strongest negative effect on outcome were: subarachnoid haemorrhage (P = 0.000001), multiple (P = 0.000005) or large ( P 0.0007) contusions, subdural haematoma (P = 0.001) and brain swelling (P = 0.002). A significant coexistence of these four injuries was found. We hypothesise that in many patients the contusions may have been the primary injuries of this complex and should therefore be considered as a main injury determining outcome in this study. We believe that such findings may support a rational approach to optimising pedal cyclist head protection.

Bicycle helmet campaigns and head injuries among children. Does poverty matter?

OBJECTIVES

To assess the impact of a community based bicycle helmet programme aimed at children aged 5-12 years (about 140,000) from poor and well off municipalities.

METHODS

A quasi-experimental design, including a control group, was used. Changes in the risk of bicycle related head injuries leading to hospitalisation were measured, using rates ratios.

RESULTS

Reductions in bicycle related head injuries were registered in both categories of municipalities. Compared with the pre-programme period, the protective effect of the programme during the post-programme period was as significant among children from poor municipalities (RR= 0.45 95%CI 0.26 to 0.78) as among those from richer municipalities (RR=0.55 95%CI 0.41 to 0.75).

CONCLUSION

Population based educational programmes may have a favourable impact on injury risks in poor areas despite lower adoption of protective behaviours.

CT scan findings in mild head trauma: a series of 2,000 patients

The present study describes the cranial computed tomography (CT) scan findings of 2,000 cases of mild head trauma (HT) in Curitiba, Southern Brazil. The mean age of the entire series was 30.8 +/-19 years. The overall male to female ratio was 2:1. The most common causes of head injury were interpersonal aggression (17.9%), falls (17.4%), automobile accidents (16.2%), falls to the ground (13.1%) and pedestrian injuries (13 %). Alcohol intoxication was associated with HT in 158 cases (7.9%). A normal CT scan was seen in 60.75% (1215) and an abnormal CT scan in 39.25% (785) of patients. Out of 785 abnormal CT scan, 518(65.9%) lesions were related to HT. The most common CT scan HT related findings were: soft tissue swelling (8.9 %), skull fractures (4.3 %), intracranial and subgaleal hematomas (3.4% and 2.4 %), brain swelling (2 %) and brain contusion (1.2%). Out of 785 abnormal CT scans, 267 (34.1%) lesions were not related to head trauma. Incidental CT scan findings included brain atrophy (5.9%), one calcification (5.2%) several calcifications (2.4%) (probably neurocysticercosis in most cases), ischemic infarct (1.9%) and leukoaraiosis (1.3%). These findings showed the importance of CT scan examination in mild head injuries. Further studies to identify mild HT patients at higher risk of significant brain injury are warranted in order to optimize its use.

Effects of state helmet laws on bicycle helmet use by children and adolescents

OBJECTIVE

To evaluate the effectiveness of state helmet laws in increasing the use of bicycle helmets by children and adolescents under age 16.

SETTING

United States.

METHODS

A cross sectional study of factors associated with the likelihood of helmet use by children and adolescents. Data were derived from a national random digit dial telephone survey of bicycle riders. A multiple logistic regression analysis was used to quantify the independent effect of the state helmet laws on helmet use.

RESULTS

Helmet use was systematically related to the presence of state helmet laws (odds ratio 2.65; 95% confidence interval (CI) 1.29 to 5.44). The increase in the average probability of helmet use attributable to state helmet laws was 18.4% (95% CI 17.8% to 19.0%).

CONCLUSIONS

State helmet laws significantly increase helmet use by children and play an important part in any comprehensive effort designed to achieve this goal.

Barriers to bicycle helmet use

OBJECTIVE

To determine why people do or do not wear helmets while bicycling.

METHODS

A survey was conducted from August through October 1999. Two survey areas were chosen for this study: local public schools and paved bicycle trails. For the school arm of the study, 3 public elementary, middle, and high schools were selected from 3 different regions of Rochester, Minnesota, for participation in the study. For the bicycle arm of the study, 3 paved trails located in southeastern Minnesota were selected. A total of 2970 surveys were distributed to the public school system, and 463 surveys were collected from bicyclists on the paved bicycle trails. The survey population was split into 3 age categories for analysis: child (7-10), adolescent (11-19), and adult (older than 19).

RESULTS

Of the 2970 surveys distributed to Rochester public schools, 2039 (69%) were returned for analysis. Seventy-eight of the surveys that were completed in the public school system were discarded for the following reasons: age <10 years (35), insufficient completion (24), and selection of every reason for not wearing a bicycle helmet (19). A total of 463 surveys were completed on the 3 paved bicycle trails. One survey from the paved bicycle trail arm of the study was discarded because of insufficient completion. The total number of surveys used for statistical analysis was 2424. The distribution of male (52.7%) and female (47.3%) participants was similar. No significant difference in bicycle helmet use was found between genders. The age groups with the highest rate of bicycle helmet use were 50 to 59 years (62%) and older than 59 years (70%). The age groups with the lowest rate of bicycle helmet use were 11 to 19 years (31%) and 30 to 39 years (30%). The most common reasons given for not wearing a bicycle helmet were "uncomfortable," "annoying," "it's hot," "don't need it," and "don't own one." Bicycle helmet use was significantly influenced by peer helmet use in all 3 age groups. Children also were more likely to wear a bicycle helmet when their parents wore bicycle helmets. A majority of respondents in all 3 age groups indicated that bicycle helmets provided either "moderate" or "great" protection from head injury, although significantly more adults (65.9%) than adolescents (43.9%) believed that the protection afforded by bicycle helmets was "great." Despite this belief, a majority of adolescents and adults indicated that there was only a "slight risk" of head injury when bicycling without a helmet. Participants in all 3 categories were more likely to wear a bicycle helmet when they indicated either that there was a "great risk" of head injury when bicycling without a helmet or that helmets provided "great protection" from head injury. Adolescents and adults who believed that bicycling without a helmet put one at "great risk" for head injury also were more likely to indicate that helmets provided "great protection" from head injury.

CONCLUSIONS

The prevalence of bicycle helmet use remains low despite research indicating the high level of head injury risk when bicycling without a helmet and the significant protection afforded by bicycle helmets. With the information provided by this survey, a well-designed intervention to increase the use of bicycle helmets can be implemented. Suggestions for a campaign to promote an increase in bicycle helmet use include focusing efforts on males and females between 11 and 19 years and 30 and 39 years of age; educating the public on new bicycle helmet designs that address comfort, ventilation, and fashion; educating adolescents on the significant protection from head injury afforded by bicycle helmets; and educating the public on the risk and severity of head injury associated with bicycling without a helmet. The influence of parents and peers on bicycle helmet use may be targeted through education and statements such as, "If you wear a bicycle helmet, you are not only protecting yourself, you are also helping to protect your friends and/or children." bicycle, helmet, injury, accident, prevention.

Prevention of bicycle-related injuries: helmets, education, and legislation

Efforts to reduce the toll of bicycle-related head injuries illustrate how the basic public health principles of surveillance, epidemiologic study, intervention, and evaluation can have a substantial impact on an injury problem, using a variety of injury-prevention strategies. Head injuries are the leading cause of serious morbidity and mortality from bicycle crashes. Helmets have been shown to reduce bicycle-related head injuries for cyclists of all ages involved in all types of crashes including those with motor vehicles. Helmet use has been promoted using educational campaigns, helmet subsidies, and legislation. Careful evaluation of these strategies has shown that these interventions increase helmet use and decrease the incidence of bicycle injuries. The model developed for the prevention of bicycle injuries is widely applicable to other injury problems.

Bicycle-related injuries among preschool children

STUDY OBJECTIVE

To describe the circumstances, severity, and outcome of bicycle-related injuries among hospitalized children younger than 5 years and to compare injuries in young children (< 5 years) and older children (5 to 14 years).

METHODS

We studied a case series of children (0 to 14 years) with bicycle-related injuries requiring hospital admission reported to the National Pediatric Trauma Registry (NPTR) between January 1986 and June 1996.

RESULTS

Bicycle-related injuries were reported for 4,041 patients; 219 (5%) involved children younger than 5 years. Two young children and 124 older children (3%) wore bicycle helmets. Young children were less likely than older ones to be injured in the street (46% versus 81%, P < .001) and were more likely to be injured at home in the driveway or yard (39% versus 9%, P < .001). Interaction with a motor vehicle contributed to injuries in 31% of young children and 47% of older children (P < .001). Forty-five percent of young children and 56% of older children sustained head injuries (P < .002). The fractions of children in each age group with facial trauma, abdominal or thoracic injury, and fractures were similar. Pediatric Trauma Scores, Glasgow Coma Scale scores, operating room use rates, and median number of hospital days were similar for both age groups. Rehabilitation or extended care was required by 1% of young children and 2% of older children. Two deaths occurred among young children (1%); 2% of older children died.

CONCLUSION

Of patients with bicycle-related injuries reported to the NPTR, a minority are young children, but they have injuries similar in severity and outcome to those of older children. Because young children sustain severe injuries, including head trauma, helmets are indicated for them, as well as for older children.

Evaluation of a four-year bicycle helmet promotion campaign in Quebec aimed at children ages 8 to 12: impact on attitudes, norms and behaviours

OBJECTIVE

This study evaluated a four-year bicycle helmet promotion campaign.

METHODS

Children's attitudes, social norms, intentions to wear a bicycle helmet as well as helmet ownership were measured. Evaluation was based on a pre-experimental static group comparison design repeated at two (1991) and four years (1993) after implantation, with a non-randomized control group. 3,424 students completed a self-administered questionnaire (experimental: 2,097, control: 1,327).

RESULTS

The program had a significant impact on helmet ownership (1989: 4%; 1991: 26%; 1993: 56%). The program was the principal predictor of high intention to use a bicycle helmet. Time was the principal predictor of ownership with exposure to the program being the next predictor.

CONCLUSION

This study showed that time is an important factor in bicycle helmet acquisition, and that a long-term community-based program can accelerate the process of adopting this behaviour.

Observational evaluation of compliance with traffic regulations among helmeted and nonhelmeted bicyclists

STUDY OBJECTIVE

To evaluate whether helmeted bicyclists are more compliant with traffic regulations than nonhelmeted bicyclists.

METHODS

This prospective observational study, using a convenience sample, was conducted during daylight hours at three separate intersections, marked with legal stop signs, near the campus of a major university. Data collected included helmet use, legal hand signal use to indicate a turn or stop, and whether the bicyclist came to a complete stop before proceeding through the intersection.

RESULTS

A total of 1,793 bicyclists were evaluated. Only 8.8% of the bicycle riders were wearing helmets. Helmeted bicyclists were 2.6 times more likely than nonhelmeted bicyclists to make legal stops (P < .000001; odds ratio [OR], 3.1; 95% confidence interval [CI], 2.1 to 4.6). They were also 7.1 times more likely to use hand signals (P < .000001; OR, 7.2; 95% CI, 2.8 to 18.2).

CONCLUSION

Helmeted bicycle riders showed a significantly greater compliance with two traffic laws than nonhelmeted bicyclists. They were 2.6 times more likely to stop at stop signs and 7.1 times more likely to use legal hand signals. This very strong association of helmet use with safer riding habits has implications for injury-control efforts aimed at preventing bicycle-related injuries.

Evaluation of a four-year bicycle helmet promotion campaign in Quebec aimed at children ages 8 to 12: impact on attitudes, norms and behaviours

OBJECTIVE

This study evaluated a four-year bicycle helmet promotion campaign.

METHODS

Children's attitudes, social norms, intentions to wear a bicycle helmet as well as helmet ownership were measured. Evaluation was based on a pre-experimental static group comparison design repeated at two (1991) and four years (1993) after implantation, with a non-randomized control group. 3,424 students completed a self-administered questionnaire (experimental: 2,097, control: 1,327).

RESULTS

The program had a significant impact on helmet ownership (1989: 4%; 1991: 26%; 1993: 56%). The program was the principal predictor of high intention to use a bicycle helmet. Time was the principal predictor of ownership with exposure to the program being the next predictor.

CONCLUSION

This study showed that time is an important factor in bicycle helmet acquisition, and that a long-term community-based program can accelerate the process of adopting this behaviour.

A comparative analysis of alcohol in fatal and nonfatal bicycling injuries

Bicycling is the leading cause of recreational injury, resulting in more than half a million emergency department visits and about 900 deaths each year in the United States. Previous research on bicycling injury was conducted predominantly in children and focused on the effectiveness of safety helmets. Few studies have examined the role of alcohol in bicycling injuries. This study examined the magnitude of and factors related to alcohol involvement in fatal and nonfatal bicycling injuries, and tested the hypothesis that alcohol intoxication is associated with significantly increased likelihood of fatality given a serious bicycling injury. Medical examiner data on all fatally injured bicyclists aged 10 years or older from 1987 to 1994 in Maryland (fatal cases, n = 63) were compared with trauma registry data on all injured bicyclists who were treated at a regional trauma center during the same time period (nonfatal cases, n = 253) on variables related to blood alcohol concentrations (BACs), demographic characteristics, and injury circumstances. The fatal cases were more likely than the nonfatal cases to have positive BACs (30% vs. 16%, p < 0.01) and to be legally intoxicated (i.e., BACs > or = 0.10%) (22% vs. 13%, p < 0.01). For both fatal and nonfatal cases, intoxication was more prevalent among victims who were male, aged 20 to 39 years, or who were injured at nighttime (7:00 PM to 6:59 AM). Bicyclists who died at the scene were four times as likely as those who died at hospitals to be legally intoxicated (35% vs. 9%, p < 0.02). Given a serious bicycling injury, intoxication was associated with significantly increased likelihood of fatality, with an adjusted odds ratio of 2.8 (95% confidence interval, 1.3 to 6.3). This increased likelihood of fatality was probably due in part to the fact that the rate of helmet use at the time of injury among the intoxicated was much lower than among the sober (6% vs. 31%, p < 0.05). Results indicate that alcohol plays an important role in fatal and serious bicycling injuries. Preventing intoxicated biking should be incorporated into helmet campaigns and other bicycle safety programs.

Predictors of injury among 1638 riders in a recreational long-distance bicycle tour: Cycle Across Maryland

To assess the incidence of and risk factors for injuries in a group of bicyclists with a well-defined exposure to bicycling, we conducted a prospective study of 1638 recreational bicyclists who rode in the 6-day 339-mile Cycle Across Maryland tour in 1994. The mean age of participants was 39 years (range, 7 to 79), and two-thirds were male. All riders wore helmets. During the tour there were 85 acute traumatic injuries (15.4 per 100,000 person-miles), 76 overuse injuries (13.7 per 100,000 person-miles), and 37 other medical problems (6.7 per 100,000 person-miles). Acute traumatic injuries were associated with a history of racing versus none (relative risk = 2.2, 95% confidence limits = 1.3, 3.7) and with inexperience, no previous Cycle Across Maryland tours versus one or more (relative risk = 1.7, 95% confidence limits = 1.04, 2.8), but not with sex, training, or prior injuries. Inexperience and lack of preride conditioning were risk factors for overuse injuries. The most common overuse injuries and medical problems were knee pain, hand or wrist numbness, foot blisters, insect stings and bites, and heat and dehydration. Study results provide exposure-based incidence rates of bicyclist injuries and suggest overuse injuries may be reduced by increased preride conditioning.

Head injuries from bicycle accidents

This study comprises a total of 159 victims from bicycle accidents treated as inpatients at the Department of Neurosurgery, University of Bonn between January 1987 and June 1995. It was our aim to define the severity and features of bicycle-related head injuries in a defined population. Our results show that 33% of admitted bicycle victims sustained severe head injuries (Glasgow Coma Score 3-8). Neurosurgical operations were performed in 49% of patients and were mainly related to the evacuation of an extracerebral hematoma. Of the 159 bicycle victims, 112 (70%) made a good recovery, 11 (7%) remained moderately and 4 (3%) severely disabled, and 26 (16%) had died at follow-up (mean 2 years). In conclusion, our data indicate that bicycle-related trauma accounts for a substantial proportion of all head injuries requiring neurosurgical treatment. Active (e.g. traffic regulations, education of riders) and passive measures (e.g. safety helmets) can be expected to reduce both incidence and severity of head injuries among bicyclists.

Head injuries and bicycle helmet laws

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.

The effects of a 4-year program promoting bicycle helmet use among children in Quebec

OBJECTIVES

This study assessed the effectiveness of a 4-year program of bicycle helmet promotion that targeted elementary school children in one region of Quebec. The program revolved primarily around persuasive communication and community organization, combining standard educational activities and activities to facilitate helmet acquisition and use.

METHODS

Helmet use was compared between more than 8000 young cyclists in municipalities exposed or not exposed to the program. Factors influencing helmet use were controlled through the use of multivariate analyses.

RESULTS

Helmet use increased from 1.3% before program implementation to 33% in 1993. The program was clearly effective in most cycling circumstances and for various groups of children. However, the benefits of the program were unequally distributed; the program was one third as effective in poorer municipalities as in "average-rich" ones.

CONCLUSIONS

This community-based program that combined various types of activities appeared to be effective. New intervention models are needed to ensure an equitable distribution of benefits.

Fatal cycling injuries

Cycling accidents are responsible for significant morbidity and mortality, especially in boys under the age of 16. While most cycling injuries result from simple falls from the bicycle, the majority of fatalities are caused by head injuries resulting from accidents involving motor vehicles. It is estimated that up to 85% of all cycling fatalities caused by head injuries could be prevented by the use of an appropriate cycling helmet. Although the majority of adult cyclists wear helmets the reverse is true for children, who comprise the greatest proportion of all cyclists. Intensive educational programmes increase the number of cycling helmets that are sold, but have a lesser effect on the number used while cycling. Legislation, compassionately enforced on minors, i.e. with an understanding attitude towards their developmental stage, is the only proven technique that substantially improves rates of helmet use by young cyclists. Such legislation reduces their morbidity and mortality from head injuries. This article reviews the epidemiological factors associated with traumatic cycling injuries and the nature of these injuries. Special attention is paid to head injuries and the evidence that these are largely preventable with the use of appropriate 3-layered cycling helmets, the features of which are detailed. Factors promoting or discouraging helmet use by children are reviewed. These include the following factors: age, since helmet use is highest in mature cyclists and lowest in children because of negative peer pressure; parental example, including an attitude of safety consciousness and parental concern; higher levels of education; access to discounted helmets; public campaigns to promote helmet use; and, most importantly, appropriate legislation. But it is clear that appropriate legislation making helmet use compulsory for all cyclists is the only effective method for increasing helmet use, especially by young cyclist. Such legislation would reduce a mortality rate among young cyclists that has been equated to the mortality caused by some childhood infections in the pre-vaccination era. Some argue that physicians have a particular responsibility for promoting effective legislation for mandatory helmet use so that young children can be 'vaccinated' against the risk of the modern childhood epidemic; fatal head injury while cycling.

Children and bicycles: what is really happening? Studies of fatal and non-fatal bicycle injury

OBJECTIVES

The objectives of the study were to ascertain the causes of accidents, injuries, and deaths in children who ride bicycles. Fatality and injury rates were also studied in order to compare with other studies.

METHODS

Two studies of children were undertaken in children aged less than 15 years. In the first (retrospective fatality study), children who died as a result of a bicycle incident during the period 1981-92 were reviewed. In the second (prospective injury study) data were obtained prospectively between April 1991 and June 1992 about children who were injured while riding a bicycle and treated at a public hospital in Brisbane.

RESULTS

Study 1: fatality rates for boys were twice those for girls. The rate was highest for boys of 14 years in the metropolitan area at 6.23/100,000. All deaths involved vehicles, and the majority involved head injury or multiple injuries including head injury. Study 2: similar numbers of children were injured at onroad and off-road locations. Faculty riding was described by the rider or caregiver as the cause in 62.5% of cases. The most common time of injury was between 3 and 6 pm on both school and non-school days. Only 5.5% of all incidents involved a moving vehicle.

CONCLUSIONS

Bicycle riding by children is a common cause of injury, particularly for boys. Equal numbers of injuries occurred on the road as at other locations. Faulty riding caused most accidents. Injury prevention for bicycle riders should involve not only compulsory wearing of helmets, but should also include education and training about safe riding habits, separation of motorised vehicles from bicycles, modified helmet design to incorporate facial protection, and improved handlebar design.

Factors related to the presence of head injury in bicycle-related pediatric trauma patients

Using data from the National Pediatric Trauma Registry, this study examined the characteristics of bicycle-related head injury, factors related to the presence of head injury, and different outcomes of head injury up to the time of discharge. Of the 2,333 patients ages 0 to 14 years who were admitted to trauma centers because of bicycle-related injury during 1989 through 1992, more than one-half (54%) sustained head injury, predominantly concussions and skull fractures. With adjustment for age, sex, and motor vehicle involvement, children who had pre-existing mental disorders, who did not wear a helmet at the time of injury, or who were injured on roads had a significantly increased likelihood of sustaining head injuries. Patients with a head injury were four times as likely as patients with no head injury to be treated in intensive care units, and were almost twice as likely to develop complications. Head injury was associated with an increased risk of inhospital fatality and high prevalence rates of communication and behavior impairments at discharge. Although it is urgent to increase helmet use substantially by child bicyclists, special attention should be paid to high-risk groups, such as children with mental disorders and children who are likely to ride in traffic.

Injury control recommendations for bicycle helmets. Centers for Disease Control and Prevention

These guidelines were developed by the Centers for Disease Control and Prevention for state and local agencies and organizations planning programs to prevent head injuries among bicyclists through use of bicycle helmets. The guidelines contain information on the magnitude and extent of the problem of bicycle-related head injuries and potential impact of increased helmet use; characteristics of helmets, including biomechanical characteristics, helmet standards, and performance in actual crash conditions; barriers that impede increased helmet use; and approaches to increasing use of bicycle helmets within the community. In addition, bicycle helmet legislation and community educational campaigns are evaluated.

Injuries resulting from bicycle collisions

OBJECTIVE

To review all bicycle crash-related injuries reported to the Oregon Injury Registry for 1989 to compare patterns of injury and other features in adults vs children and adolescents.

METHODS

A retrospective descriptive study was conducted using data from the Oregon Injury Registry. For 1989, this registry included all injury-related deaths and approximately 75% of hospital admissions of 24 hours or more for injury in the State of Oregon. Deaths, helmet use, neurologic injuries, and concurrent ethanol use were evaluated for all patients and for the two age groups.

RESULTS

There were 311 bicycle-related injured patients in the registry for 1989; 122 (40%) were adults (age > or = 21 years) and 189 (60%) were children/adolescents (age < 21 years). Approximately 69% of both age groups were male. All of the 15 deaths involved male patients and most deaths [10/15 (67%)] involved injured adults. Bicycle vs motor vehicle collisions accounted for 14 (93%) deaths and 106 (34%) of all registry entries. While only 19 (15%) of the injured adults had elevated blood alcohol levels, half the adults who died had been intoxicated. Helmet use was rare with only 12 (4%) of all the injured riders known to have been helmeted; no rider who died was known to have been helmeted. Neurologic injuries were common. In children, 27 (14%) had sustained skull fractures, 36 (19%) intracranial injuries, and one (0.5%) a spinal injury. In adults, 13 (10%) had sustained skull fractures, 32 (26%) intracranial injuries, and three (2%) spinal injuries.

CONCLUSIONS

Although children account for 60% of the serious bicycle injuries in Oregon, adults account for 67% of the deaths. Helmet use is rare, brain injuries are frequent, and alcohol use appears to be a contributing factor in cycling deaths among adults. Public education efforts should be directed to both adult and pediatric populations, emphasizing safe cycling practices and helmet use.

Bicycle helmet use patterns in the United States. A description and analysis of national survey data

While there have been considerable efforts to promote bicycle helmet use in the United States in recent years, little information has been available on actual helmet usage patterns. Based on the results of a recent national survey, this article provides information on current helmet usage patterns, the types of helmets in use, and the reasons why bicycle riders use or do not use helmets. It also presents a statistical analysis of the factors associated with helmet use. These factors are determined and quantified with a probit regression model, a type of qualitative response model that can be used to estimate the expected probabilities of helmet use for individual bicyclists and for various population subgroups. The regression analysis shows that helmet use is systematically related to riding patterns, rider characteristics, and household demographics.

A prospective investigation of the impact of alcohol consumption on helmet use, injury severity, medical resource utilization, and health care costs in bicycle-related trauma

STUDY OBJECTIVE

To examine if a relationship exists between bicycle-related injuries, consumption of alcohol, helmet use, and medical resource utilization.

DESIGN

A prospective cohort study with data from emergency department, operating room, and inpatient records.

SETTING

University-based trauma center in a medium-sized metropolitan area.

TYPE OF PARTICIPANTS

Adult victims (age > or = 18 years) of bicycle-related injury presenting to the emergency department. A total of 350 patients made up the study population.

RESULTS

Group 1 consisted of 29 patients (8.3%) with detectable blood alcohol levels at the time of the incident. Group 2 (321 patients) had a measured blood alcohol level of 0 or no clinical indication of alcohol consumption. Group 1 mean Injury Severity Score was 10.3, with six (20.7%) sustaining at least one severe anatomic injury. Group 2 had an Injury Severity Score of 3.3 (p < 0.0001), with only 4.4% (p = 0.0013) sustaining severe anatomic injury. Mean length of hospitalization for group 1 was 3.5 days, including a mean of 1.4 intensive care unit days. Mean hospitalization (0.5 days, p < 0.0001) and intensive care unit (0.1 days, p < 0.0001) were significantly lower in group 2. Mean combined hospital and physician charges were more than six times greater for group 1 ($7,206) than group 2 patients ($1170, p < 0.0001).

CONCLUSION

In patients presenting with bicycle-related injuries, prior consumption of alcohol is highly associated with greater injury severity, longer hospitalization, and higher health care costs. This information is useful in the development of injury prevention strategies to decrease incidence and severity of adult bicycle injuries.

Alcohol in fatally injured bicyclists

Bicycling injury results in about 580,000 emergency room visits and 900 deaths each year in the United States. Alcohol involvement in bicycling injury has not been well documented in the literature. Using data from the Fatal Accident Reporting System, blood alcohol concentrations (BACs) among fatally injured bicyclists ages 15 years or older were examined for the years 1987-1991. Of 1,711 bicyclists who were killed at age 15 or older and tested for alcohol, 32% were positive and 23% legally intoxicated. Adjusted for age, time of crash, and other variables, male decedents were 3.3 times [95% confidence interval (CI) 2.1, 5.1] as likely as female decedents to be BAC positive, and 3.9 times (95% CI 2.2, 6.8) as likely to be legally intoxicated. Decedents ages 25 to 34 and those who died from nighttime crashes also had significantly increased likelihood of being BAC positive and being legally intoxicated. Even among decedents aged 15-19, who were legally prohibited from drinking, 14% had positive BACs. Further studies are needed to confirm the causal relationship between alcohol use and bicycling injury and to better understand the factors related to drinking and biking. The role of alcohol should be seriously considered in developing strategies of bicycling injury control and prevention.

A cost-benefit analysis of legislation for bicycle safety helmets in Israel

Legislation requiring bicyclists to wear helmets in Israel will, over a helmet's 5-year duration (assuming 85% compliancy, 83.2% helmet efficiency for morbidity, and 70% helmet efficiency for mortality), save approximately 57 lives and result in approximately 2544 fewer hospitalizations; 13,355 and 26,634 fewer emergency room and ambulatory visits, respectively; and 832 and 115 fewer short-term and long-term rehabilitation cases, respectively. Total benefits ($60.7 million) from reductions in health service use ($44.2 million), work absences ($7.5 million), and mortality ($8.9 million) would exceed program costs ($20.1 million), resulting in a benefit-cost ratio of 3.01:1.

Psychosocial factors associated with the use of bicycle helmets among children in counties with and without helmet use laws

We examined the extent to which psychosocial factors, in addition to the presence of a law, are associated with the use of bicycle helmets. A mailed questionnaire was completed by 3494 children in fourth, seventh, and ninth grades in three Maryland counties: Howard County, which had a law requiring child bicyclists to wear helmets and an educational campaign; Montgomery County, which had an educational campaign but no law; and Baltimore County, which had neither. Overall, 19% of the respondents reported having worn a bicycle helmet on their most recent ride. In a multiple logistic regression, children's use of helmets in all three counties was significantly associated with their beliefs about the social consequences of wearing helmets and the extent to which their friends wear helmets. Significant interactions were also found, suggesting that in the presence of a law, an educational campaign, or both, children's use of helmets was associated more with social concerns than with parental influences or cognitive factors, such as beliefs about the need for helmets or perceptions of risk. To increase helmet use, the issues of stylishness, comfort, and social acceptability of wearing helmets need to be addressed and more widespread adoption of bicycle helmet laws should be encouraged.

Acute injuries from mountain biking

We questioned members of 2 southern California off-road bicycling organizations about injuries associated with the use of all-terrain bicycles. Cyclists were asked about riding and safety habits, the kind(s) of injury sustained with their most recent accident and whether they sought medical treatment, and the circumstances of the accident. Of 459 mailed surveys, 268 (58.4%) were returned. Respondents (82.8% of whom were male) ranged in age from 14 to 68 years. Of these, 225 (84%) had been injured while riding all-terrain bicycles, 51% in the past year. Although most injuries were characterized as minor, 26% required professional medical care, and 4.4% of those injured were admitted to hospital. Extremity injuries--abrasions, lacerations, contusions--occurred in 201 (90%) cyclists with 27 (12%) sustaining a fracture or dislocation. High levels of helmet use (88%) may explain the low occurrence of head and neck trauma (12%). Frequent riding and riding on paved terrain were associated with increased severity of injury, although most accidents--197 (87.6%)--occurred off paved roads. These results suggest that, compared with regular bicyclists, all-terrain cyclists have more, but not necessarily more severe, injuries. Clinicians and emergency medical personnel should be aware that the increasing popularity of off-road cycling may change the frequency and nature of bicycling injuries.

Fatal bicycle accidents in children: a plea for prevention

We reviewed the coroner's records of all fatal bicycle accidents occurring in children (aged 0 to 15 years) in Ontario (pediatric population, 2,007,230) between January 1, 1985 and December 31, 1989. The injuries sustained were documented and scored with anatomical injury scores (Abbreviated Injury Score 1985 and Injury Severity Score) and categorized as unsurvivable or survivable. The causes and circumstances were documented from police accident reports. Eighty-one deaths resulted from bicycle accidents, an annual mortality rate of 1.44 deaths per 100,000 children per year. In 74 (91%) of these cases the injuries were deemed unsurvivable, 89% of which were head injuries. Seventy-eight (96%) of the deaths resulted from collisions with motor vehicles. No victim was wearing a helmet at the time of injury. In 70% of the deaths, the cyclist was considered to have caused the collision, either because of a violation of a road traffic law or poor road sense. These findings suggest that more emphasis should be placed on primary and secondary injury prevention by such methods as bicycle safety education for children and the promotion of bike helmet use. In addition, in view of the high incidence of unsurvivable head injury, the introduction of legislation requiring the use of protective helmets should be considered.