Linda Rothman

Children in Side-impact Motor Vehicle Crashes: Seating Positions and Injury Mechanisms

BACKGROUND This study aimed to describe the injury mechanisms of children involved in side-impact car crashes, particularly as these relate to seating position, and to estimate the danger of the near-side seating position. METHODS A prospective two-center study of children involved in severe car crashes in Canada was conducted as well as a retrospective cohort study of children involved in crashes reported in the Fatality Analysis Reporting System (FARS) and the National Automotive Sampling System: Crashworthiness Data System (NASS CDS). RESULTS Children sitting at the side the car was struck (near-side position) sustained severe head, trunk, and limb injuries. Many of these injuries were attributable to direct intrusion, but some occurred without direct damage to the occupant compartment. Center-seat and far-side occupants had severe injuries only when unrestrained. Injury severity scores were higher for children seated on the near side, and this was statistically significant (p = 0.024) The analysis of Fatality Analysis Reporting System data showed that the risk of fatality was higher for children seated in the near-side position than for those in the center-seat position. The fatality risk ratio was 2.53 (95% confidence interval [CI], 2.08-3.07) for restrained children and 1.84 (95% CI, 1.57-2.17) for unrestrained children. Analysis of the NASS-CDS data showed that for restrained children, severe injury (ISS > or = 16) was more common among those on the near side (7 per 1,000 children) than among those in the center seat (2 per 1,000) or on the far-side seat (1 per 1,000) (p < 0.001). CONCLUSIONS Severe injuries to near-side occupants occurred in both the presence and absence of compartment intrusion. A typical pattern of head, chest, and extremity injury similar to that seen among child pedestrians was observed among near-side child occupants in side-impact crashes. The center seat was statistically safer than the near-side seat, particularly for restrained child occupants. Scene information may be useful to trauma teams for the prediction of injury type and location. Avoiding intrusion and preventing the occupant from striking the vehicle wall are both important to side-impact protection for children. Improvement of the vehicle safety cage may protect against intrusion injuries. Seating two child occupants in inboard seating positions may provide additional protection against intrusion injuries, and also may protect against nonintrusion injuries.

The effect of safer play equipment on playground injury rates among school children

Background: Changes to Canadian Standards Association (CSA) standards for playground equipment prompted the removal of hazardous equipment from 136 elementary schools in Toronto. We conducted a study to determine whether applying these new standards and replacing unsafe playground equipment with safe equipment reduced the number of school playground injuries. Methods: A total of 86 of the 136 schools with hazardous play equipment had the equipment removed and replaced with safer equipment within the study period (intervention schools). Playground injury rates before and after equipment replacement were compared in intervention schools. A database of incident reports from the Ontario School Board Insurance Exchange was used to identify injury events. There were 225 schools whose equipment did not require replacement (nonintervention schools); these schools served as a natural control group for background injury rates during the study period. Injury rates per 1000 students per month, relative risks (RRs) and 95% confidence intervals (CIs) were calculated, adjusting for clustering within schools. Results: The rate of injury in intervention schools decreased from 2.61 (95% CI 1.93–3.29) per 1000 students per month before unsafe equipment was removed to 1.68 (95% CI 1.31–2.05) after it was replaced (RR 0.70, 95% CI 0.62–0.78). This translated into 550 injuries avoided in the post-intervention period. In nonintervention schools, the rate of injury increased from 1.44 (95% CI 1.07–1.81) to 1.81 (95% CI 1.07–2.53) during the study period (RR 1.40, 95% CI 1.29–1.52). Interpretation: The CSA standards were an effective tool in identifying hazardous playground equipment. Removing and replacing unsafe equipment is an effective strategy for preventing playground injuries.

Are school zones effective? An examination of motor vehicle versus child pedestrian crashes near schools.

Objective: To analyse the relationships between factors related to school location and motor vehicle versus child pedestrian collisions. Methods: Data on all police-reported motor vehicle collisions involving pedestrians less than 18 years of age that occurred in Toronto, Canada, between 2000 and 2005 were analysed. Geographic information systems (GIS) software was used to assess the distance of each collision relative to school location. The relationships between distance from school and collision-related factors such as temporal patterns of school travel times and crossing locations were analysed. Results: Study data showed a total of 2717 motor vehicle versus child (<18) pedestrian collisions. The area density of collisions (collisions/area), particularly fatal collisions, was highest in school zones and decreased as distance from schools increased. The highest proportion of collisions (37.3%) occurred among 10–14-year-olds. Within school zones, collisions were more likely to occur among 5–9-year-old children as they travelled to and from school during months when school was in session. Most collisions within school zones occurred at midblock locations versus intersections. Conclusions: Focusing interventions around schools with attention to age, travel times, and crossing location will reduce the burden of injury in children. Future studies that take into account traffic and pedestrian volume surrounding schools would be useful for prevention efforts as well as for promotion of walking. These results will help identify priorities and emphasise the importance of considering spatial and temporal patterns in child pedestrian research.

Influence of social and built environment features on children walking to school: An observational study

OBJECTIVES To estimate the proportion of children living within walking distance who walk to school in Toronto, Canada and identify built and social environmental correlates of walking. METHODS Observational counts of school travel mode were done in 2011, at 118 elementary schools. Built environment data were obtained from municipal sources and school field audits and mapped onto school attendance boundaries. The influence of social and built environmental features on walking counts was analyzed using negative binomial regression. RESULTS The mean proportion observed walking was 67% (standard deviation=14.0). Child population (incidence rate ratio (IRR) 1.36), pedestrian crossover (IRR 1.32), traffic light (IRR 1.19), and intersection densities (IRR 1.03), school crossing guard (IRR 1.14) and primary language other than English (IRR 1.20) were positively correlated with walking. Crossing guard presence reduced the influence of other features on walking. CONCLUSIONS This is the first large observational study examining school travel mode and the environment. Walking proportions were higher than those previously reported in Toronto, with large variability. Associations between population density and several roadway design features and walking were confirmed. School crossing guards may override the influence of roadway features on walking. Results have important implications for policies regarding walking promotion.

Walking and child pedestrian injury: a systematic review of built environment correlates of safe walking.

Background The child active transportation literature has focused on walking, with little attention to risk associated with increased traffic exposure. This paper reviews the literature related to built environment correlates of walking and pedestrian injury in children together, to broaden the current conceptualization of walkability to include injury prevention. Methods Two independent searches were conducted focused on walking in children and child pedestrian injury within nine electronic databases until March, 2012. Studies were included which: 1) were quantitative 2) set in motorized countries 3) were either urban or suburban 4) investigated specific built environment risk factors 5) had outcomes of either walking in children and/or child pedestrian roadway collisions (ages 0-12). Built environment features were categorized according to those related to density, land use diversity or roadway design. Results were cross-tabulated to identify how built environment features associate with walking and injury. Results Fifty walking and 35 child pedestrian injury studies were identified. Only traffic calming and presence of playgrounds/recreation areas were consistently associated with more walking and less pedestrian injury. Several built environment features were associated with more walking, but with increased injury. Many features had inconsistent results or had not been investigated for either outcome. Conclusions The findings emphasise the importance of incorporating safety into the conversation about creating more walkable cities.

Booster seat laws and child fatalities: a case–control study

A case–control study examined, primarily, the association between booster seat laws and fatalities among children in frontal collisions and, secondarily, the association between booster seat laws and reported restraint use, and restraint use and child fatalities. Children who died in a crash in the US were cases, and children who survived a fatal crash were controls. Subjects were child passengers (4–8 years old) in the Fatality Analysis Reporting System Database, 1995–2005. In states with a booster seat law, children were less likely to die than in states without a law (OR 0.80; 95% CI 0.66 to 0.98). They were also more likely to be restrained (adjusted OR 1.59; 95% CI 1.21 to 2.09) and were more likely to be correctly restrained (adjusted OR 4.44; 95% CI 3.18 to 6.20). It is concluded that booster seat laws are associated with a decrease in child deaths and an increase in correct restraint use among children involved in a fatal crash in the USA.

Motor Vehicle-Pedestrian Collisions and Walking to School: The Role of the Built Environment

OBJECTIVES: Initiatives to increase active school transportation are popular. However, increased walking to school could increase collision risk. The built environment is related to both pedestrian collision risk and walking to school. We examined the influence of the built environment on walking to school and child pedestrian collisions in Toronto, Canada. METHODS: Police-reported pedestrian collision data from 2002 to 2011 for children ages 4 to 12, proportion of children walking to school, and built environment data were mapped onto school attendance boundaries. Collision rates were calculated by using 2006 census populations and modeled by using negative binomial regression. RESULTS: There were 481 collisions with a mean collision rate of 7.4/10 000 children per year. The relationship between walking proportion and collision rate was not statistically significant after adjusting for population density and roadway design variables including multifamily dwelling density, traffic light, traffic calming and 1-way street density, school crossing guard presence, and school socioeconomic status. CONCLUSIONS: Pedestrian collisions are more strongly associated with built environment features than with proportions walking. Road design features were related to higher collision rates and warrant further examination for their safety effects for children. Future policy designed to increase children’s active transportation should be developed from evidence that more clearly addresses child pedestrian safety.

Ejections of young children in motor vehicle crashes

PURPOSE The purpose of this study was to report the incidence of ejection from the vehicle among children involved in motor vehicle crashes, and to describe a novel mode of ejection from child safety seats. METHODS The U.S. National Automotive Sampling System General Estimates System and the Fatality Analysis Reporting System databases from 1995 through 1999 were analyzed. A prospective two-center study of children involved in severe car crashes in Canada was performed. RESULTS Only 0.2% of 5.5 million children involved in crashes experienced ejection, but 1924 (29%) of 6570 child fatalities involved ejections. Only 2.2% of children experienced rollover crashes, but these contributed 1832 (28%) of 6570 child passenger fatalities. Among 56 crashes, 5 restrained young children were ejected, 4 in rollover crashes. Ejection of a toddler through the shoulder straps of a forward-facing child safety seat was the mechanism of ejection in three of the five cases. CONCLUSION Ejection from the vehicle is common (29%) among fatally injured children. Shoulder straps alone (as found in T-shield or overhead shield child seats) may not prevent the ejection of toddlers from child safety seats during rollovers.

Pedestrian crossing location influences injury severity in urban areas

Background Pedestrian incidents represent an increasing proportion of serious injuries resulting from motor vehicle collisions in Canada. However, few studies have examined the effect of pedestrian crossing location in urban areas on injury severity. The objective of this study was to investigate the relationship between pedestrian–motor vehicle collision injury severity and crossing location. Methods This study was a population-based analysis of police-reported pedestrian collision data. The study group was pedestrian collisions from 1 January 2000 to 31 December 2009 in Toronto. Main outcome measures were a binary indicator of severe injury, and a four-level categorical variable of injury severity. The exposure variable was crossing at mid-block with no traffic control compared to signalised intersection. Analysis was via binary and multinomial logistic regression models to estimate ORs of injury severity with 95% CIs. Results The analysis included 9575 pedestrian–motor vehicle collisions, of which 7325 occurred at signalised intersections when crossing and 2230 occurred at uncontrolled mid-block locations when crossing without right of way. Uncontrolled mid-block collisions resulted in greater injury severity when controlling for road type. The odds of severe injury were 1.75 (95% CI 1.07 to 2.86) for children, 2.55 (95% CI 2.13 to 3.05) for adults and 1.68 (95% CI 1.23 to 2.28) for older adults. The odds of death at uncontrolled mid-block crossings were 4.97 (95% CI 3.11 to 7.94) in adults and 3.49 (95% CI 2.07 to 5.89) in older adults. Conclusions Crossing at uncontrolled mid-block locations resulted in greater injury severity compared with crossing at signalised intersections. This has important implications for pedestrian behaviour and traffic environment design and emphasises the need for safe pedestrian crossings on urban roads.

Mechanism of injury affects 6-month functional outcome in children hospitalized because of severe injuries

BACKGROUND The burden of childhood injury is often described using vital statistics for mortality and hospital admissions as a measure of morbidity. Hospital admissions, however, reflect the process of care and do not directly measure childrens functional disability. The purpose of this study was to determine the influence of mechanism of injury on the functional outcome 6 months after injury in children in an inpatient trauma unit of a pediatric referral hospital. METHODS A retrospective cohort of 357 children aged 2 to 15 with an Injury Severity Score (ISS) > 12 was studied to determine the relationship between mechanism of injury (based on International Classification of Diseases, Ninth Revision e-code) and functional outcome 6 months after hospital discharge. Wee Functional Independence Measure (WeeFIM) was used to assess functional outcome. Any child with a WeeFIM score less than the maximum (of 126) attainable was classed as requiring assistance, and the relative risk of requiring assistance at 6 months was calculated for each injury mechanism. Poisson regression analysis was used to assess the importance of mechanism of injury, after adjusting for age, gender, ISS, and a primary diagnosis of central nervous system (CNS) injury. RESULTS Mechanism of injury had a significant effect on the functional outcome at 6 months: 72% of pedestrians, 64% of cyclists struck by cars, and 59% of injured motor vehicle occupants required assistance during daily activities. By contrast, only 27% of those injured playing sports and 22% of cyclists injured without motor vehicle involvement required assistance. The relative risk of children requiring assistance was similar with or without adjustment for age, gender, ISS, and CNS injury. CONCLUSION Mechanism of injury is significantly associated with requiring assistance 6 months postdischarge, even after controlling for age, injury severity, and the presence of a CNS injury. These data are important both when discussing the prognosis for an individual patient and also when considering the population impact of childhood injuries.