Risk Factors for Bicycling Injuries in Children and Adolescents: A Systematic Review

CONTEXT

Child and adolescent bicycling is beneficial, but injuries occur and can be severe and costly.

OBJECTIVE

To systematically review the individual and environmental factors associated with bicycling injury risk in children and adolescents.

DATA SOURCES

Fourteen electronic databases were searched.

STUDY SELECTION

Two authors independently assessed potentially relevant articles for eligibility. The inclusion criteria were as follows: bicyclists younger than 20 years old; examined individual and environmental characteristics of bicycling crashes; compared injured and uninjured bicyclists or bicyclists with different types or severity of injury; study designs with a predetermined comparison group; and published in English from January 1990 to May 2015. The exclusion criteria were outcomes related to helmet use, helmet legislation, or mountain biking, and comparisons of census-based injury rates.

DATA EXTRACTION

Data on study design, setting, population, injury definitions, injury risk factors, and results were extracted. Risk of bias was assessed by using the Newcastle-Ottawa Scales.

RESULTS

Fourteen articles were included. Lower socioeconomic status, riding on the road, riding in rural compared with urban areas, and riding on the sidewalk were associated with bicycling injury. Bicycling safety education did not protect children against future injury. Injuries related to a motor vehicle collision were more severe than other bicycling injuries.

LIMITATIONS

Study heterogeneity prevented meta-analyses. Study quality was affected by inadequate definitions of study groups and self-reported data.

CONCLUSIONS

Lower socioeconomic status and riding location were associated with bicycling injury and severity increased with motor vehicle collisions. The bicycling environment is a promising avenue for prevention.

The epidemiology of fatal cyclist crashes over a 14-year period in Alberta, Canada

Background

Cycling is a popular recreational activity and a common transportation option; however, cycling-related injuries can be fatal. There are few studies of cycling fatalities in Canada and none in a region as sparsely populated as Alberta.

Methods

A chart review was conducted of cyclists involved in fatal crashes. Charts for deaths that occurred between 1998 and 2011 (inclusive) were identified and abstracted onto standardized forms. Personal characteristics and crash circumstances, including motor vehicle involvement, were collected; mechanisms of fatally injured cyclists across age groups were compared. Census data were used to calculate region-specific and provincial age-specific cycling fatality rates.

Results

Charts from 101 deaths over 14 years were reviewed. Events mainly occurred during the summer. There were more fatalities in urban (64 [63 %]) than in rural settings. Collisions with motor vehicles and cyclist-only crashes accounted for 68 and 15 % of cycling fatalities, respectively. Most (87 %) deceased cyclists were male, and the median age was 47 years (inter-quartile range: 25, 58). The population-based fatality rate over the study period was highest among deceased cyclists older than 65. Helmet use was reported in 26 (26 %) cases and increased with age. Alcohol use was detected in 25 (25 %) cases.

Conclusions

Fatal cycling crashes in Alberta typically involve adults riding on urban roads and collisions with motor vehicles. While helmet legislation has reduced non-fatal cycling head injuries, deaths may be further prevented by physical separation of cyclists and motor vehicles and avoidance of substance use while operating bicycles.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-2476-9) contains supplementary material, which is available to authorized users.

Severe bicycling injury risk factors in children and adolescents: a case-control study

BACKGROUND

Bicycling is the most common cause of sports and recreation injury in children and adolescents; yet, there is limited evidence on the factors associated with severe bicycling injuries in youth.

METHODS

Case-control study of injured bicyclists less than 18 years old seen in seven emergency departments (EDs) from May 2008 to October 2010. Cases were bicyclists hospitalized after their ED visit (severe injury). Controls were bicyclists seen and discharged from the ED (non-severe injury). Personal, environmental, and crash characteristics were collected by interview. Injury data were collected from medical charts. Crude and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) from logistic regression were used to estimate the odds of hospitalization associated with risk factors. Multiple imputation techniques were employed to address missing data.

RESULTS

There were 1470 participants including 119 cases. Those ages 13-17 had the highest proportion (23%) of severe injuries resulting from motor vehicle [MV] collision. In models including age, sex and MV collision, being male (OR: 2.02; 95% CI: 1.21-3.38), not wearing a helmet (OR: 2.18; 95% CI: 1.43-3.31) and MV collision (OR: 3.91; 95% CI: 2.26-6.78) were significant risk factors for severe injury. Riding on a paved surface (OR: 0.63; 95% CI: 0.41-0.97) and utilitarian (school, work) bicycling (OR: 0.44; 95% CI: 0.2-0.94) decreased injury risk. Results were similar, apart from utilitarian bicycling (OR: 0.49; 95% CI: 0.22-1.06), after imputation for missing data.

CONCLUSION

Bicycle-MV collisions increase severe injury risk in youth, and adolescents are often injured in these events. This suggests separating bicyclists from MVs or traffic calming strategies could improve safety.

The relationship between visibility aid use and motor vehicle related injuries among bicyclists presenting to emergency departments

BACKGROUND

Little is known about the effectiveness of visibility aids (VAs; e.g., reflectors, lights, fluorescent clothing) in reducing the risk of a bicyclist-motor-vehicle (MV) collision.

PURPOSE

To determine if VAs reduce the risk of a bicyclist-MV collision.

METHODS

Cases were bicyclists struck by a MV and assessed at Calgary and Edmonton, Alberta, Canada, emergency departments (EDs) from May 2008 to October 2010. Controls were bicyclists with non-MV injuries. Participants were interviewed about their personal and injury characteristics, including use of VAs. Injury information was collected from charts. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for VAs during daylight and dark conditions, and adjusted for confounders using logistic regression. Missing values were imputed using chained equations and adjusted OR estimates from the imputed data were calculated.

RESULTS

There were 2403 injured bicyclists including 278 cases. After adjusting for age, sex, type of bicycling (commuting vs. recreational) and bicyclist speed, white compared with black (OR 0.52; 95% CI 0.28, 0.95), and bicyclist self-reported light compared with dark coloured (OR 0.67; 95% CI 0.49, 0.92) upper body clothing reduced the odds of a MV collision during daylight. After imputing missing values, white compared with black (OR 0.57; 95% CI: 0.32, 0.99) and bicyclist self-reported light compared with dark coloured (OR 0.71; 95% CI 0.52, 0.97) upper body clothing remained protective against MV collision in daylight conditions. During dark conditions, crude estimates indicated that reflective clothing or other items, red/orange/yellow front upper body clothing compared with black, fluorescent clothing, headlights and tail lights were estimated to increase the odds of a MV collision. An imputed adjusted analysis revealed that red/orange/yellow front upper body clothing colour (OR 4.11; 95% CI 1.06, 15.99) and tail lights (OR 2.54; 95% CI: 1.06, 6.07) remained the only significant risk factors for MV collisions. One or more visibility aids reduced the odds of a bicyclist MV collision resulting in hospitalization.

CONCLUSIONS

Bicyclist clothing choice may be important in reducing the risk of MV collision. The protective effect of visibility aids varies based on light conditions, and non-bicyclist risk factors also need to be considered.

Cyclist head and facial injury risk in relation to helmet fit: a case-control study

INTRODUCTION

We examined the effect of bicycle helmet fit and position on head and facial injuries.

METHODS

Cases were helmeted cyclists with a head (n=297) or facial (n=289) injury. Controls were helmeted cyclists with other injuries, excluding the neck. Participants were interviewed in seven Alberta emergency departments or by telephone; injury data were collected from charts. Missing values were imputed using chained equations and custom prediction imputation models.

RESULTS

Compared with excellent helmet fit, those with poor fit had increased odds of head injury (odds ratio [OR] = 3.38, 95% confidence interval [CI]: 1.06-10.74). Compared with a helmet that stayed centred, those whose helmet tilted back (OR = 2.90, 95% CI: 1.54-5.47), shifted (OR = 1.91, 95% CI: 1.01-3.63) or came off (OR = 6.72, 95% CI: 2.86-15.82) had higher odds of head injury. A helmet that tilted back (OR = 4.81, 95% CI: 2.74-8.46), shifted (OR = 1.83, 95% CI: 1.04-3.19) or came off (OR = 3.31, 95% CI: 1.24-8.85) also increased the odds of facial injury.

CONCLUSION

Our findings have implications for consumer and retail education programs.

Feature-specific terrain park-injury rates and risk factors in snowboarders: a case-control study

Background

Snowboarding is a popular albeit risky sport and terrain park (TP) injuries are more severe than regular slope injuries. TPs contain man-made features that facilitate aerial manoeuvres. The objectives of this study were to determine overall and feature-specific injury rates and the potential risk factors for TP injuries.

Methods

Case–control study with exposure estimation, conducted in an Alberta TP during two ski seasons. Cases were snowboarders injured in the TP who presented to ski patrol and/or local emergency departments. Controls were uninjured snowboarders in the same TP. κ Statistics were used to measure the reliability of reported risk factor information. Injury rates were calculated and adjusted logistic regression was used to calculate the feature-specific odds of injury.

Results

Overall, 333 cases and 1261 controls were enrolled. Reliability of risk factor information was κ>0.60 for 21/24 variables. The overall injury rate was 0.75/1000 runs. Rates were highest for jumps and half-pipe (both 2.56/1000 runs) and lowest for rails (0.43/1000 runs) and quarter-pipes (0.24/1000 runs). Compared with rails, there were increased odds of injury for half-pipe (OR 9.63; 95% CI 4.80 to 19.32), jumps (OR 4.29; 95% CI 2.72 to 6.76), mushroom (OR 2.30; 95% CI 1.20 to 4.41) and kickers (OR 1.99; 95% CI 1.27 to 3.12).

Conclusions

Higher feature-specific injury rates and increased odds of injury were associated with features that promote aerial manoeuvres or a large drop to the ground. Further research is required to determine ways to increase snowboarder safety in the TP.

Trends in head injuries associated with mandatory bicycle helmet legislation targeting children and adolescents

BACKGROUND

Bicycling related head injuries (HIs) can be severe. Helmet use reduces head injury risk; however, there are few controlled studies of the effect of helmet legislation. We conducted this study to investigate changes in HIs after bicycle helmet legislation targeting those <18 in Alberta, Canada in 2002.

METHODS

Bicyclist and pedestrian (control) HI rates and HIs as a proportion of all injuries were compared for the three years (1999-2001) before and four years (2003-2006) after bicycle helmet legislation in three age groups (children: <13, adolescents: 13-17, and adults: 18+).

RESULTS

There were 41,270 ED visits and 2782 hospitalizations for bicyclists and 9836 ED visits and 2029 hospitalizations for pedestrians (excluding the legislation year 2002). The rate of ED HIs declined for child bicyclists and child pedestrians, while the rate of non-HIs declined in adult bicyclists and child pedestrians. The rate of hospitalized HIs declined in child bicyclists and all ages of pedestrians while non-HI rates declined for child and adult pedestrians. Non-HI rates for adolescent and adult bicyclists increased. After adjusting for sex and location, the proportion of ED bicycle HIs declined by 9% (APR=0.91; 95% CI: 0.86, 0.95) in children, was unchanged among adolescents and increased in adults (APR=1.08; 95% CI: 1.01, 1.15). The proportion of bicycle HI related hospitalizations decreased by 30% (APR=0.70; 95% CI: 0.55, 0.90) in children, 36% (APR=0.64; 95% CI: 0.49, 0.84) in adolescents and 24% (APR=0.76; 95% CI: 0.63, 0.91) in adults. There were no observed changes in the proportion of pedestrian HIs resulting in ED visits or hospitalizations.

INTERPRETATION

Our data indicate significant declines in the proportion of child bicyclist ED HIs and child, adolescent and adult bicyclist HI hospitalizations. This is in contrast to no significant trends in the proportion of ED or hospitalized HIs among pedestrians and the unexpected increases in the proportion of ED HIs for adult bicyclists. Comparing bicyclist and pedestrian trends in the proportion of child and adolescent HIs suggests a bicycle helmet legislation effect.

Assessing inter-rater agreement of environmental audit data in a matched case-control study on bicycling injuries

BACKGROUND

Environmental audit tools must be reliable in order to accurately estimate the association between built environmental characteristics and bicycling injury risk.

OBJECTIVE

To examine the inter-rater agreement of a built environment audit tool within a case-control study on the environmental determinants of bicycling injuries.

METHODS

Auditor pairs visited locations where bicycling injuries occurred and independently recorded location characteristics using the Systematic Pedestrian and Cyclist Environmental Scan (SPACES). Two case groups were defined: (1) where a bicyclist was struck by a motor-vehicle (MV) and (2) where the bicyclist's injuries required hospitalisation. The two corresponding control groups were (1) where non-MV bicycle-related injuries occurred and (2) where minor bicycle-related injuries occurred. Inter-rater reliability of each item on the tool was assessed using observed agreement and κ with 95% CI.

RESULTS

Ninety-seven locations were audited. Inter-observer agreement was generally high (≥95%); most items had a 1-2% difference in responses. Items with ≥5% differences between raters included path condition, slope and obstructions. For land use, path and roadway characteristics, κ ranged from 0.3 for presence of offices and cleanliness to 0.9 for schools and number of lanes; overall, 78% of items had at least substantial agreement (κ≥0.61). For bicyclists struck by a MV the proportion of items with substantial agreement was 60%, compared with 73% for non-MV related injuries. For hospitalisations and minor bicycle-related injuries, 76% of items had substantial agreement.

CONCLUSIONS

Agreement was substantial for most, but not all SPACES items. The SPACES provides reliable quantitative descriptions of built environmental characteristics at bicycling injury locations.

Mountain bike terrain park-related injuries: an emerging cause of morbidity

This case-control study describes the profile of bicyclists injured in mountain bike terrain parks (MBTPs) and examines risk factors for severe injury among MBTP riders. Cases were hospitalised bicyclists injured in MBTPs. Controls were bicyclists injured in MBTPs who were discharged from the emergency department. No significant differences were observed in the distribution of age and sex between cases and controls. A higher proportion of cases compared with controls suffered a head injury (22%), fracture (41%) or internal organ injury (32%). Controls suffered a higher proportion of superficial injuries (26%), sprains (10%) or wounds (16%). Upper extremity protective equipment (e.g. elbow or shoulder pads) was used more by cases than controls (23% vs. 11%, p = 0.03). Riders who self-reported cycling faster than usual had significantly higher risk of severe injury compared with others. The risk of severe injury may be reduced by encouraging bicyclists to control their speed or by modifying MBTP design to limit the opportunity to gain speed.