Passenger seating position and the risk of passenger death or injury in traffic crashes

Risk and Protective Factors for Injury in Adult Front- and Rear-Seated Motor Vehicle Occupants in New York State

Although seatbelt use is known to reduce motor vehicle occupant crash injury and death, rear-seated adult occupants are less likely to use restraints. This study examines risk and protective factors associated with injury severity in front- and rear-seated adults involved in a motor vehicle crash in New York State. The Crash Outcome Data Evaluation System (CODES) (2016-2017) was used to examine injury severity in front- and rear-seated occupants aged 18 years or older (N = 958,704) involved in a motor vehicle crash. CODES uses probabilistic linkage of New York State hospitalization, emergency department, and police and motorist crash reports. Multivariable logistic regression models with MI analyze employed SAS 9.4. Odds ratios are reported as OR with 95% CI. The mortality rate was approximately 1.5 times higher for rear-seated than front-seated occupants (136.60 vs. 92.45 per 100,000), with rear-seated occupants more frequently unrestrained than front-seated occupants (15.28% vs. 1.70%, p < 0.0001). In adjusted analyses that did not include restraint status, serious injury/death was higher in rear-seated compared to front-seated occupants (OR:1.272, 1.146-1.412), but lower once restraint use was added (OR: 0.851, 0.771-0.939). Unrestrained rear-seated occupants exhibited higher serious injury/death than restrained front-seated occupants. Unrestrained teens aged 18-19 years old exhibit mortality per 100,000 occupants that is more similar to that of the oldest two age groups than to other young and middle-aged adults. Speeding, a drinking driver, and older vehicles were among the independent predictors of serious injury/death. Unrestrained rear-seated adult occupants exhibit higher severe injury/death than restrained front-seated occupants. When restrained, rear-seated occupants are less likely to be seriously injured than restrained front-seated occupants.

Injury Patterns in Vehicle Crashes: The Significance of Occupant Seating Position

OBJECTIVES

 Investigating patterns among the outcomes of patients involved in motor vehicle accidents (MVAs) can provide information necessary to guide targeted interventions to improve road traffic safety. Our purpose is to identify any differences between passenger and driver injury severity and overall clinical course after MVAs.

METHODS

 We performed a retrospective review and analysis of 3,693 patients involved in MVAs from 2016 to 2021. We divided the data into two groups, drivers and passengers, and compared the Injury Severity Score (ISS), Revised Trauma Score (RTS) on admission, days in the Intensive Care Unit (ICU), length of hospital stay (LOS), post Emergency Department (ED) disposition, discharge (DC) disposition, and signs of life on arrival (SOLA) to the ED. We compared mean ISS, New Injury Severity Score (NISS), RTS, length in ICU and LOS using a student's T-test and SOLA, post-ED and DC disposition using Chi-square analysis.

RESULTS

 We did not find any statistically significant difference in ISS, RTS, days in ICU, LOS, or SOLA between the drivers and passengers. However, we did find a statistically significant difference in the post-ED (X2= 113.743, p=<0.0001) and DC disposition (X2=41.172, p=<0.0001) of drivers and passengers. After the ED and DC, more passengers were transferred to a higher level of care than expected, while the inverse was true for drivers. The number of drivers discharged to Skilled Nursing Facilities (SNFs) was also higher than expected, further contributing to the observed difference in DC disposition.  Conclusion: Our study found no statistically significant difference between driver and passenger injury severity, length of hospital stay, days in ICU, and SOLA after an MVA. The clinical courses of the two groups were found to be significantly different based on post-ED and DC disposition data. We identified limitations, such as a relatively small sample size and insufficient data on specific car seat locations for passengers, underscoring the need for a more nuanced exploration. Future research must broaden its scope to encompass diverse crash scenarios, vehicle design and safety technologies, seat belt dynamics, and age- and gender-specific vulnerabilities.

Motor Vehicle Crash and Hospital Charges in Front- and Rear-Seated Restrained and Unrestrained Adult Motor Vehicle Occupants

There are reports that historically higher mortality observed for front- compared to rear-seated adult motor vehicle (MV) occupants has narrowed. Vast improvements have been made in strengthening laws and restraint use in front-, but not rear-seated occupants suggesting there may be value in expanding the science on rear-seat safety.

METHODS

A linked 2016-2017 hospital and MV crash data set, the Crash Outcomes Data Evaluation System (CODES), was used to compare characteristics of front-seated (n = 115,939) and rear-seated (n = 5729) adults aged 18 years and older involved in a MV crash in New York State (NYS). A primary enforced seat belt law existed for front-seated, but not rear-seated occupants. Statistical analysis employed SAS 9.4.

RESULTS

Compared to front-seated occupants, those rear-seated were more likely to be unrestrained (21.2% vs. 4.3%, p < 0.0001) and to have more moderate-to-severe injury/death (11.9% vs. 11.3%, p < 0.0001). Compared to restrained rear-seated occupants, unrestrained rear-seated occupants had higher moderate-to-severe injury/death (21.5% vs. 7.5%, p < 0.0001) and 4-fold higher hospitalization. More than 95% of ejections were unrestrained and had 7-fold higher medical charges. Unrestrained occupants' hospital stays were longer, charges and societal financial costs higher.

CONCLUSIONS

These findings extend the science of rear-seat safety in seriously injured rear-seated occupants, document increased medical charges and support the need to educate consumers and policy makers on the health and financial risks of adults riding unrestrained in the rear seat. The lack of restraint use in adult rear-seated motor vehicle occupants consumes scarce health care dollars for treatment of this serious, but largely preventable injury.

Fatal blunt chest trauma: an evaluation of rib fracture patterns and age

The following study was undertaken to determine if any specific occupant characteristics, crash factors, or associated injuries identified at autopsy could predict the occurrence or number of fractured ribs in adults. Data were accrued from the Traffic Accident Reporting System (TARS) and coronial autopsy reports from Forensic Science SA, Adelaide, South Australia, from January 2000 to December 2020. A total of 1475 motor vehicle fatalities were recorded in TARS between January 2000 and December 2020, and 1082 coronial autopsy reports were identified that corresponded to TARS fatal crash data. After applying exclusion criteria involving missing data, 874 cases were included in the analysis. Of the 874 cases, 685 cases had one or more rib fractures. The leading cause of death for those with rib fractures was multiple trauma (54%), followed by head injury (17%) and chest injuries (10%). The strongest predictor of one or more rib fractures was increasing age (p < 0.001). Other factors found in the regression to be predictive of the number of rib fractures were the presence of a variety of other injuries including thoracic spinal fracture, lower right extremity fracture, splenic injury, liver injury, pelvic fracture, aortic injury, lung laceration, and hemothorax. Age is most likely associated with increasing rib fractures due to reduced tolerance to chest deflection with greater injuries occurring at lower magnitudes of impact. The association of other injuries with rib fractures may be a marker of higher impact severity crashes.

U.S. vehicle occupancy trends relevant to future automated vehicles and mobility services

OBJECTIVE

Identifying current occupant travel patterns can inform decision making regarding the design, regulation, and occupant protection systems helpful for automated vehicle systems and mobility services.

METHODS

Two travel data sets were analyzed to quantify travel patterns: the 2017 National Household Travel Survey (NHTS), which provides data on household trips logged for a 24-h period, and the 2011-2015 National Automotive Sampling System-General Estimates System (NASS-GES), which contains data sampled from police-reported crashes. Analysis identified trends with driver age and gender, occupant age and gender, time of day, day of week, trip purpose, trip duration, vehicle type, as well as occupant role as solo driver, driver of others, single passenger, or multiple passengers.

RESULTS

In NHTS, the median trip duration is 15 min; only 10% of trips last longer than 40 min. Trip duration does not vary with occupant role or vehicle type. Variations with trip time of day and day of week show a unimodal pattern for weekends, as well as weekday trips for those aged 55 years and older and non-solo occupants aged 18 to 29 years. Other occupant groups have a bimodal weekday travel pattern with peak trips corresponding to morning and evening rush hours.In GES, approximately half of occupants are solo drivers. Female drivers aged 55 and older travel alone 60% of the time, and drivers under age 18 and female drivers aged 30 to 54 drive alone on less than 45% of trips. Approximately 13% of occupants are single passengers, and 16% travel with a driver and at least 1 other passenger. About 16% of occupants are front seat passengers.

CONCLUSIONS

This analysis of vehicle occupancy provides insights on what ridership of future automated vehicles and expanded ride-hailing services may look like. Because half of occupants are solo drivers, only 16% are multiple passengers, and median trip length is just 15 min, proposed alternative seating arrangements intended to promote comfort and passenger interaction may not represent the typical future vehicle use case in the United States. Knowledge of current occupancy patterns can help automated vehicle designers and regulators develop safe seating scenarios that meet customer needs.

Autopsy findings in drivers and passengers from fatal motor vehicle collisions: limited differences in injury patterns and toxicological test results

We performed a retrospective study of the injuries and characteristics of occupant fatalities in motor vehicle collisions in southeast Norway. The goal was to provide updated knowledge of injuries sustained in modern vehicles and detect possible differences in injury pattern between drivers and passengers. Forensic autopsy reports, police, and collision investigation reports from 2000 to 2014 were studied, data extracted and analyzed.

A total of 284 drivers, 80 front-seat passengers, and 37 rear-seat passengers were included, of which 67.3% died in front collisions, 13.7% in near-side impacts, 13.5% in rollovers and 5.5% in other/combined collisions. Overall, 80.5% died within one hour after the crash. The presence of fatal injuries to the head, neck, thorax and abdomen were observed in 63.6%, 10.7%, 61.6% and 27.4% respectively. All occupants with severe injuries to the head or neck had signs of direct impact with contact point injuries to the skin or skull. Injuries to the heart and spleen were less common in front-seat passengers compared to drivers. Seat belt abrasions were more common and lower extremity fractures less common in both front-seat and rear-seat passengers compared to drivers. Blood alcohol and/or drug concentrations suggestive of impairment were present in 30% of all occupants, with alcohol more often detected among front-seat passengers compared to drivers.

Few driver-specific and passenger-specific patterns of injury could be identified. When attempting to assess an occupant’s seating position within a vehicle, autopsy findings should be interpreted with caution and only in conjunction with documentation from the crash scene.

Is the front passenger seat always the "death seat"? An application of a hierarchical ordered probit model for occupant injury severity

Although many studies have investigated the correlations between injury severities and seat positions, few researchers explored the correlates of injury severities (e.g., seat positions) within a crash that results in multiple occupant injuries. Therefore, we examine the injury correlates within and between crashes, and study the correlations between seat positions and occupant injury severity by constructing a hierarchical ordered probit model. A total of 20,327 occupant injuries in 16,405 motor vehicle crashes in South Australia (2012 - 2016) are used. The results of this study indicate that the rear left passenger seat is associated with a 7.66% higher chance of getting injured (including moderate and severe injury), and the front left passenger seat is associated with a 2.94% higher chance of getting injured compared with the driver seat. Besides, the higher injury chances for other passenger seats including the rear right and rear middle seats are 4.97% and 4.74%, respectively, compared with the driver seat. Thus, this study offers passengers insightful suggestions about how to protect themselves by choosing the right passenger seat in a vehicle.

Investigating traffic fatality trends and restraint use among rear-seat passengers in the United States, 2000-2016

INTRODUCTION

Motor-vehicle crash is one of the leading causes of unintentional injury death in the United States. Previous studies focused on fatalities among drivers and front-seat passengers, with a limited number of studies examining rear-seat passenger fatalities. The objectives of this study were to assess trends in rear-seat passenger motor-vehicle fatalities in the United States from 2000 to 2016 and to identify demographic factors associated with being unrestrained among fatally injured rear-seat passengers.

METHODS

Rear-seat passenger fatality data were obtained from the Fatality Analysis Reporting System (FARS) database. The fatality rate ratios for overall rear-seat passengers and for different age and sex groups were determined by comparing fatality rates in 2000 and 2016 using random effects models. Risk ratios of being unrestrained for age and sex groups were obtained using general estimating equations.

RESULTS

Compared to 2000, the overall rear-seat passenger fatality rate in 2016 decreased by 44% (95% confidence interval [CI]: 39-49%). In particular, the fatality rate among rear-seat passengers decreased more in males than females, and passengers aged 14-19 years experienced a larger decline than all other age groups. Fatally injured male rear-seat passengers had a higher risk of being unrestrained (adjusted risk ratio: 1.06, 95% CI: 1.04-1.07) than their female counterparts, and both youngest (≤13 years) and oldest (65-85 years) passengers were less likely to be unrestrained than those aged 20-64 years.

CONCLUSIONS

Overall, fatality rates among rear-seat passengers have declined, with differential degrees of improvement by age and sex. Practical Applications: Continued restraint use enforcement campaigns targeted at teenagers and males would further preserve them from fatal injuries and improve traffic safety for the overall population.

Prevalence of child passenger restraint use in Shantou, China from 2012 to 2017

BACKGROUND

Child passenger safety is an important public health problem in China. This study aimed to examine the prevalence of child passenger restraint use while riding in a car in the city of Shantou in China from 2012 to 2017.

METHODS

Three large-scale cross-sectional observational studies were conducted in 2012, 2015 and 2017, respectively. The observation sites included randomly selected hospitals, kindergartens, and primary and secondary schools. The outcome measures included the changes in percentages of seating position (e.g., front vs. rear), whether sitting on lap, and use of child restraint systems (CRS) or seat belts by year and by age group. Descriptive statistics, Chi-square tests and logistic regression were used to address the study aims.

RESULTS

A total of 9858 commuting children aged 17 and younger were observed in passenger cars in Shantou, China during the study. The proportion of children aged 0-5 sitting on adult's lap decreased from 26.6% in 2012 to 24.6% in 2017, while the proportion of CRS use among the children sitting in the rear row increased among children aged 0-5 (from 0.7% in 2012 to 14.2% in 2017) and children aged 6-11 (from 0.7% in 2012 to 2.4% in 2017). Comparing children aged 0-11 in 2012, children in the same ages were less likely to sit in the front row in 2015 (OR = 0.42, 95%CI = 0.37, 0.48) and in 2017 (OR = 0.27, 95%CI = 0.23, 0.31). Children aged 0-11 were more likely to sit in the rear row with CRS use in 2015 (OR = 8.50, 95%CI = 5.44, 13.28) and in 2017 (OR = 10.95, 95%CI = 7.02, 17.08) comparing with children in the same ages in 2012. As for children aged 12-17, they were more likely to use seat belt in 2017 (OR = 1.40, 95%CI = 1.06, 1.85) compared with those children in 2012.

CONCLUSIONS

While child passenger safety behaviors improved from 2012 to 2017 in Shantou, China, more efforts are needed to protect child passengers from injuries.

The effect of verified pediatric trauma centers, state laws, and crash characteristics on time trends in adolescent motor vehicle fatalities, 1999-2015

BACKGROUND

Motor vehicle crashes are a leading cause of adolescent death from trauma. A recent study found American College of Surgeons-verified pediatric trauma centers (vPTC) were inversely correlated with pediatric mortality, but the analysis was limited to a single year. This study assesses the contribution of vPTCs, crash characteristics, and state driver laws on 15- to 17-year-old motor vehicle crash mortality for all 50 states from 1999 to 2015.

METHODS

Prospective data on motor vehicle fatalities, crash characteristics, state driving laws, and American College of Surgeons-verified trauma centers were collected from publicly available sources for 50 US states from 1999 to 2015. A mixed fixed/random effects multivariate regression model was fitted to assess the relative contribution of crash characteristics, state laws, and vPTCs while controlling for state variation and time trends.

RESULTS

The final regression model included driver and crash characteristics, verified trauma centers, and state laws. Camera laws ([B = -0.57 [p < 0.001]) were associated with a 57% decrease in the rate of change in adolescent crude fatalities. The lagged Level 1 vPTC crude rate (B = -0.12 [p < .001]) was protective and contributed independently to a 12% decline in the rate of change in teen fatalities over the time period. Seat belt laws (B = -0.15 [p < 0.001]), graduated driver's license passenger restrictions (B = -0.07[p < 0.001]), graduated driver's license learner permit period (B = -0.04 [p < 0.002]), nondeployed airbag (B = -0.003 [p < 0.001]), and Hispanic heritage (B = -0.003 [p < 0.05]) were protective. Increased risk of fatality was associated with minivan (B = 0.01 [p < 0.001]), speed > 90 mph (B = 0.004 [p < 0.001]), rural roads (B = 0.002 [p < 0.002], unknown seat belt compliance (B = 0.004 [p < 0.001]), and dry road surface (B = 0.005 [p < 0.001]).

CONCLUSIONS

State camera laws during the study time frame are associated with a 57% decrease in the rate of change in adolescent crude fatalities; vPTCs during the study time period reduced overall rate of change in the crude fatality rate by 12%. State laws, restrictions on teenage passengers and longer learner's permit periods, and seat belt laws are associated with significant decreases in the crude teen mortality rate.

LEVEL OF EVIDENCE

Prospective study and prevention, level III.

High blood alcohol concentration associated with traumatic brain injury among traffic injury patients during New Year festivals in Thailand

OBJECTIVE

Road traffic injury (RTI) is one of the most significant public health problems in Thailand, especially during New Year and Songkran (Thai traditional New Year) holidays, which have the highest traffic density during the entire year. Drunk driving was reported to be one of the leading causes of RTI in Thailand. This study aimed to investigate the prevalence of patients with high blood alcohol concentration (BAC) and the association of BAC and specific organ injury during New Year and Songkran (Thai traditional New Year) holidays.

METHODS

A cross-sectional study was performed to analyze the database from the Thai Governmental Road Safety Evaluation Project. Patient data on RTIs were collected from 26 main provincial hospitals during the New Year Festival 2003 and 2004 and Songkran Festival in 2003. Patient characteristics, type of organ injured, and BAC levels were mainly analyzed.

RESULTS

During those long holidays, 2,642 RTI patients were identified, among whom 1,341 patients had high BAC levels. High BAC levels were associated with motorcycle users, male sex, middle age, teenagers, being riders or drivers, and not using protective devices. Moreover, high BAC levels were associated with brain injury.

CONCLUSION

Excessive alcohol consumption and RTIs occurred on New Year and Songkran Festival in Thailand. Legislation should be strictly used during these long holidays to control driving under the influence of alcohol, particularly among motorcyclists.

A discrete mixture regression for modeling the duration of non-hospitalization medical leave of motor accident victims

Studies analyzing the temporary repercussions of motor vehicle accidents are scarcer than those analyzing permanent injuries or mortality. A regression model to evaluate the risk factors affecting the duration of temporary disability after injury in such an accident is constructed using a motor insurance dataset. The length of non-hospitalization medical leave, measured in days, following a motor accident is used here as a measure of the severity of temporary disability. The probability function of the number of days of sick leave presents spikes in multiples of five (working week), seven (calendar week) and thirty (month), etc. To account for this, a regression model based on finite mixtures of multiple discrete distributions is proposed to fit the data properly. The model provides a very good fit when the multiples for the working week, week, fortnight and month are taken into account. Victim characteristics of gender and age and accident characteristics of the road user type, vehicle class and the severity of permanent injuries were found to be significant when accounting for the duration of temporary disability.

Evaluation of differences in injury patterns according to seat position in trauma victims survived traffic accidents

PURPOSE

Investigation of injury patterns epidemiology among car occupants may help to develop different therapeutic approach according to the seat position. The aim of the study was to evaluate and compare differences in the incidence of serious injuries, between occupants in different locations in private cars.

METHODS

A retrospective study including trauma patients who were involved in motor vehicle accidents and admitted alive to 20 hospitals (6 level Ⅰ trauma centers and 14 level Ⅱ trauma centers). We examined the incidence of injures with abbreviated injury score 3 and more, and compared their occurrence between seat locations.

RESULTS

The study included 28,653 trauma patients, drivers account for 60.8% (17,417). Front passenger mortality was 0.47% higher than in drivers. Rear seat passengers were at greater risk (10.26%) for traumatic brain injuries than front seat passengers (7.48%) and drivers (7.01%). Drivers are less likely to suffer from serious abdominal injuries (3.84%) compared to the passengers (front passengers - 5.91%, rear passengers - 5.46%).

CONCLUSION

Out of victims who arrived alive to the hospital, highest mortality was found in front seat passengers. The rate of serious chest injuries was higher as well. Rear seat passengers are at greater risk for serious traumatic brain injuries. All passengers have a greater incidence of abdominal injuries. These findings need to be addressed in order to develop "customized" therapeutic policy in trauma victims.

An analysis of the characteristics of road traffic injuries and a prediction of fatalities in China from 1996 to 2015

OBJECTIVES

This study analyzed the characteristics and burdens of road traffic injuries (RTIs) from the 3 perspectives of time, space, and population in China and predicted traffic fatalities using 2 models.

METHODS

By extracting data from the China Statistical Yearbooks and GBD 2015 (Global Health Data Exchange), we described the change in the time trend of traffic crashes and economic losses associated with the rate of motorization in China from 1996 to 2015; analyzed the geographical distribution of these events by geographic information system; and evaluated the age-, sex-, and cause-specific death rate, disability-adjusted life year (DALY) rate, years of life lost (YLL) rate, and years lost due to disability (YLD) rate lost from RTIs from 1990 to 2015. In addition, we predicted the traffic fatality (per population or vehicles) trend using the log-linear model derived from Smeed's and Borsos' models.

RESULTS

From 1996 to 2015, the motorization rate showed rapid growth, increasing from 0.023 to 0.188. With the growth in the motorization rate, the time trends of traffic crashes and economic losses in China changed, showing a tendency to first increase and then later decrease. The crashes and losses were closely correlated and mainly distributed in some of the economically developed provinces, including Zhejiang, Jiangsu, Anhui, Sichuan, and Guangdong provinces. The health burden of RTIs presented a time trend similar to that of the economic burden, and it was higher among males than females. The death rate among older pedestrians was higher. The DALY rate and YLL rate among young and middle-aged pedestrians were higher. The YLD rate among older motor vehicle drivers was higher. In addition, the fatalities per 10,000 vehicles continued to decline, and Borsos's model was better fitted to the reported traffic fatalities than Smeed's model.

CONCLUSIONS

Although the burden of RTIs in China has declined, the burden of RTIs is still heavy. Hence, RTIs remain a universal problem of great public health concern in China, and we need to work hard to reduce them.

Trends in child passenger safety practices in Indiana from 2009 to 2015

OBJECTIVE

This study reviews trends in rear-facing direction, top tether use, booster seat use, and seating position for children 12 years or younger among motor vehicle passengers in Indiana.

METHODS

This is an observational, cross-sectional survey of drivers transporting children 15 years and younger collected at 25 convenience locations randomly selected in Indiana during summers of 2009-2015. Observations were conducted by certified child passenger safety technicians (CPST). As the driver completed a written survey collecting demographic data on the driver, the CPST recorded the child demographic data, vehicle seating location, the type of restraint, direction the car safety seat (CSS) was facing, and use of the CSS harness or safety belt as appropriate. Data were analyzed for infants and toddlers younger than 24 months, children in forward-facing CSS, booster seat use, and seating position for children 12 years or younger.

RESULTS

During the study period, 4,876 drivers were queried, and 7,725 children 15 years and younger were observed in motor vehicles. Between 2009 and 2015, 1,115 infants and toddlers (age birth to 23 months) were observed in motor vehicles. For infants <1 year, rear-facing increased from 84% to 91%. During the study years the greatest increase in rear facing was for toddlers age 12-17 months (12-61%). Rear facing for those from 18-23 months did not significantly change. Of the 1,653 vehicles observed with a forward-facing car seat, using either the seat belt system or lower anchors, an average of 27% had the top tether attached. For installations of forward-facing seats using the lower anchor, 66% employed the top tether. Among children age 4-7 years observed booster seat use decreased from 72% to 65% during the observation period. Finally, for vehicle seating position, in our sample, more than 85% of children 12 years or younger were seated in a rear seat vehicle position. Unfortunately, 31% of 8- to 12-year-old children were observed in the front seat.

CONCLUSIONS

Overall, these trends demonstrate an improvement in child passenger safety practices among Indiana drivers. However, this study illuminates areas to improve child passenger safety, such as rear facing for toddlers 18 to 23 months, increasing top tether use, booster seat use, and an emphasis on rear seat position for children 8 to 12 years. This information can be used by primary care providers and child passenger safety technicians and other child passenger safety advocates to develop counseling points and targeted educational campaigns.

Rear-seat seatbelt laws and restraint use in rear-seated teen passengers traveling in passenger vehicles involved in a fatal collision on a US roadway

BACKGROUND

There is widespread belief that after childhood rear-seated motor vehicle occupants do not need to wear-seat seatbelts to travel safely. This belief is reflected in the fact that, in many states, teen passengers can ride legally unbelted in the rear seat of a passenger vehicle.

METHODS

The Fatality Analysis Reporting System for 2010-2011 was used to examine factors associated with teen use of rear-seat seatbelts (n = 3,655) and with injury outcomes of belted and unbelted rear-seated teen passengers traveling in a passenger vehicle on a US roadway. Multilevel models controlled for nonindependence of cases using SAS Glimmix. Odds ratio (OR) is reported with 95% confidence interval (CI).

RESULTS

Slightly more than half (50.8%) of rear-seated teens were restrained, but this declined linearly with age from 65.8% of 13- to 14-year-olds to 43.3% of 18- to 19-year-olds. Overall, 77.0% of rear-seat mortality occurred in unbelted teens. Passengers of belted drivers were more frequently belted (64.1% vs. 19.0%, χ = 586.2, p < 0.0001). Nearly one-fifth (18.5%) of rear-seated teens were ejected, with 95.8% of ejections in unrestrained teens. Presence of a rear-seat seatbelt law was associated with higher restraint use (55.9% vs. 40.0%, χ = 89.0, p < 0.0001). However, in adjusted multilevel, multivariable models, belt status varied by whether the seatbelt law was primary (OR, 1.60; 95% CI, 1.29-1.99) or secondary enforcement (OR, 1.33; 95% CI, 0.98-1.78).

CONCLUSION

Presence of a primary enforced rear-seat seatbelt law was associated with significantly higher belt use. Ejection was associated with higher mortality and being unrestrained. More than three quarters of rear-seated teens who died were unrestrained.

LEVEL OF EVIDENCE

Epidemiologic study, level III.

Evaluation of Severity Score in Patients with Lower Limb and Pelvic Fractures Injured in Motor Vehicle Front-Impact Collisions

Background

Lower limb and pelvic injuries and fractures occur at a very high incidence in motor vehicle accidents. In this study, the characteristics (e.g., body side, bone location, and fracture severity) of lower limb and pelvic fractures that occurred during front-impact collisions were correlated with the injured patients’ sex, age, and position in the vehicle.

Material/Methods

We retrospectively evaluated 191 patients (136 males, 55 females) who were injured in motor vehicle accidents, specifically in frontal collisions.

Results

This study revealed that most of lower limb and pelvic fractures occurred in males (71.2%; p=.000), 19–36 years old (55.5%; p=.000), small vehicles (86.4%; p=.000), and rear seat passengers (49.2%; p=.000). Fractures most commonly occurred in the left side of the body (46.6%; p=.000) and upper legs (37.7%; p=.000). Severity scores were higher (2.76) in males than females (2.07). No statistically significant was found in severity scores of patients and other personal characteristics and fracture features of patients with lower limb and pelvic fractures who were injured in a vehicle during front-impact collisions (p>0.05).

Conclusions

The results of this study will be useful for the automobile industry, forensics and criminal scientists, and for trauma research studies.

Patterns of injury sustained by car occupants with relation to the direction of impact with motor vehicle trauma — evidence based review

Motor vehicle collisions (MVCs) have been reported as the leading cause of major trauma and subsequent morbidity and mortality, for people under 20 and those between 20 and 64 years of age. Crash fatalities have significantly reduced in number since the introduction of appropriate seat belt restraints and air bags for drivers and front seat passengers. Other factors which have positively influenced the outcome of MVCs include information from pre-hospital personnel at the crash scene, regarding the vehicle's exterior and interior damage, in addition to the direction of impact. The patterns of injury sustained by car occupants during a collision depend upon the direction of impact. We provide an up to date review of the key literature regarding injury patterns sustained to occupants of light passenger vehicles (passenger cars, vans, utility vehicles and pickup trucks) in correlation with the direction of impact. We strongly believe that this knowledge can allow pre-hospital personnel and clinicians in the emergency department to gain foresight when suspecting and identifying the injuries sustained by car occupants during a motor vehicle collision.

Paired vehicle occupant analysis indicates age and crash severity moderate likelihood of higher severity injury in second row seated adults in frontal crashes

The majority of advances in occupant protection systems for motor vehicle occupants have focused on occupants seated in the front row of the vehicle. Recent studies suggest that these systems have resulted in lower injury risk for front row occupants as compared to those in the second row. However, these findings are not universal. In addition, some of these findings result from analyses that compare groups of front and second row occupants exposed to dissimilar crash conditions, raising questions regarding whether they might reflect differences in the crash rather than the front and second row restraint systems. The current study examines factors associated with injury risk for pairs of right front seat and second row occupants in frontal crashes in the United States using paired data analysis techniques. These data indicate that the occupant seated in the front row frequently experiences the more severe injury in the pair, however there were no significant differences in the rate of occurrence of these events and events where the more severe injury occurs in the second row occupant of the pair. A logistic regression indicated that the likelihood of the more severe injury occurring in the second row seated occupant of the pair increased as crash severity increased, consistent with data from anatomic test dummy (ATD) tests. It also indicated that the second row occupant was more likely to have the more severe injury in the pair if that occupant was the older occupant of the pair. These findings suggest that occupant protection systems which focus on providing protection specifically for injuries experienced by older occupants in the second row in higher severity crash conditions might provide the greatest benefit.

Copula-based regression modeling of bivariate severity of temporary disability and permanent motor injuries

The analysis of factors influencing the severity of the personal injuries suffered by victims of motor accidents is an issue of major interest. Yet, most of the extant literature has tended to address this question by focusing on either the severity of temporary disability or the severity of permanent injury. In this paper, a bivariate copula-based regression model for temporary disability and permanent injury severities is introduced for the joint analysis of the relationship with the set of factors that might influence both categories of injury. Using a motor insurance database with 21,361 observations, the copula-based regression model is shown to give a better performance than that of a model based on the assumption of independence. The inclusion of the dependence structure in the analysis has a higher impact on the variance estimates of the injury severities than it does on the point estimates. By taking into account the dependence between temporary and permanent severities a more extensive factor analysis can be conducted. We illustrate that the conditional distribution functions of injury severities may be estimated, thus, providing decision makers with valuable information.

How would increasing seat belt use affect the number of killed or seriously injured light vehicle occupants?

The expected effects of increasing seat belt use on the number of killed or seriously injured (KSI) light vehicle occupants have been estimated for three scenarios of increased seat belt use in Norway, taking into account current seat belt use, the effects of seat belts and differences in crash risk between belted and unbelted drivers. The effects of seat belts on fatality and injury risk were investigated in a meta-analysis that is based on 24 studies from 2000 or later. The results indicate that seat belts reduce both fatal and non-fatal injuries by 60% among front seat occupants and by 44% among rear seat occupants. Both results are statistically significant. Seat belt use among rear seat occupants was additionally found to about halve fatality risk among belted front seat occupants in a meta-analysis that is based on six studies. Based on an analysis of seat belt wearing rates among crash involved and non-crash involved drivers in Norway it is estimated that unbelted drivers have 8.3 times the fatal crash risk and 5.2 times the serious injury crash risk of belted drivers. The large differences in crash risk are likely to be due to other risk factors that are common among unbelted drivers such as drunk driving and speeding. Without taking into account differences in crash risk between belted and unbelted drivers, the estimated effects of increasing seat belt use are likely to be biased. When differences in crash risk are taken into account, it is estimated that the annual numbers of KSI front seat occupants in light vehicles in Norway could be reduced by 11.3% if all vehicles had seat belt reminders (assumed seat belt wearing rate 98.9%), by 17.5% if all light vehicles had seat belt interlocks (assumed seat belt wearing rate 99.7%) and by 19.9% if all front seat occupants of light vehicles were belted. Currently 96.6% of all (non-crash involved) front seat occupants are belted. The effect on KSI per percentage increase of seat belt use increases with increasing initial levels of seat belt use. Had all rear seat occupants been belted, the number of KSI front seat occupants could additionally be reduced by about 0.6%. The reduction of the number of KSI rear seat occupants would be about the same in terms of numbers of prevented KSI.

Preventive Effects of Seat Belt on Clinical Outcomes for Road Traffic Injuries

Proper seat belt use saves lives; however, the use rate decreased in Korea. This study aimed to measure the magnitude of the preventive effect of seat belt on case-fatality across drivers and passengers. We used the Emergency Department based Injury In-depth Surveillance (EDIIS) database from 17 EDs between 2011 and 2012. All of adult injured patients from road traffic injuries (RTI) in-vehicle of less than 10-seat van were eligible, excluding cases with unknown seat belt use and outcomes. Primary and secondary endpoints were in-hospital mortality and intracranial injury. We calculated adjusted odds ratios (AORs) of seat belt use and driving status for study outcomes adjusting for potential confounders. Among 23,698 eligible patients, 15,304 (64.6%) wore seat belts. Driver, middle aged (30-44 yr), male, daytime injured patients were more likely to use seat belts (all P < 0.001). In terms of clinical outcome, no seat belt group had higher proportions of case-fatality and intracranial injury compared to seat belt group (both P < 0.001). Compared to seat belt group, AORs (95% CIs) of no seat belt group were 10.43 (7.75-14.04) for case-fatality and 2.68 (2.25-3.19) for intracranial injury respectively. In the interaction model, AORs (95% CIs) of no seat belt use for case-fatality were 11.71 (8.45-16.22) in drivers and 5.52 (2.83-14.76) in non-driving passengers, respectively. Wearing seat belt has significantly preventive effects on case-fatality and intracranial injury. Public health efforts to increase seat belt use are needed to reduce health burden from RTIs.

Injury risk for matched front and rear seat car passengers by injury severity and crash type: An exploratory study

BACKGROUND

The risk of serious injury or death has been found to be reduced for some front compared to rear seat car passengers in newer vehicles. However, differences in injury severity between car occupants by seating position has not been examined. This study examines the injury severity risk for rear compared to front seat car passengers.

METHOD

A retrospective matched-cohort analysis was conducted of vehicle crashes involving injured rear vs front seat car passengers identified in linked police-reported, hospitalisation and emergency department (ED) presentation records during 2001-2011 in New South Wales (NSW), Australia. Odds ratios were estimated using an ordinal logistic mixed model and logistic mixed models.

RESULTS

There were 5419 front and 4588 rear seat passengers in 3681 vehicles. There was a higher odds of sustaining a higher injury severity as a rear-compared to a front seat car passenger, with a higher odds of rear seat passengers sustaining serious injuries compared to minimal injuries. Where the vehicle occupant was older, travelling in a vehicle manufactured between 1990 and 1996 or after 1997, where the airbag deployed, and where the vehicle was driven where the speed limit was ≥70km/h there was a higher odds of the rear passenger sustaining a higher injury severity then a front seated occupant.

CONCLUSION

Rear seat car passengers are sustaining injuries of a higher severity compared to front seat passengers travelling in the same vehicle, as well as when travelling in newer vehicles and where the front seat occupant is shielded by an airbag deployed in the crash. Rear seat occupant protective mechanisms should be examined. Pre-hospital trauma management policies could influence whether an individual is transported to a hospital ED, thus it would be beneficial to have an objective measure of injury severity routinely available in ED records. Further examination of injury severity between rear and front seat passengers is warranted to examine less severe non-fatal injuries by car seating position and vehicle intrusion.

Rear seat safety: Variation in protection by occupant, crash and vehicle characteristics

OBJECTIVES

Current information on the safety of rear row occupants of all ages is needed to inform further advances in rear seat restraint system design and testing. The objectives of this study were to describe characteristics of occupants in the front and rear rows of model year 2000 and newer vehicles involved in crashes and determine the risk of serious injury for restrained crash-involved rear row occupants and the relative risk of fatal injury for restrained rear row vs. front passenger seat occupants by age group, impact direction, and vehicle model year.

METHOD

Data from the National Automotive Sampling System Crashworthiness Data System (NASS-CDS) and Fatality Analysis Reporting System (FARS) were queried for all crashes during 2007-2012 involving model year 2000 and newer passenger vehicles. Data from NASS-CDS were used to describe characteristics of occupants in the front and rear rows and to determine the risk of serious injury (AIS 3+) for restrained rear row occupants by occupant age, vehicle model year, and impact direction. Using a combined data set containing data on fatalities from FARS and estimates of the total population of occupants in crashes from NASS-CDS, logistic regression modeling was used to compute the relative risk (RR) of death for restrained occupants in the rear vs. front passenger seat by occupant age, impact direction, and vehicle model year.

RESULTS

Among all vehicle occupants in tow-away crashes during 2007-2012, 12.3% were in the rear row where the overall risk of serious injury was 1.3%. Among restrained rear row occupants, the risk of serious injury varied by occupant age, with older adults at the highest risk of serious injury (2.9%); by impact direction, with rollover crashes associated with the highest risk (1.5%); and by vehicle model year, with model year 2007 and newer vehicles having the lowest risk of serious injury (0.3%). Relative risk of death was lower for restrained children up to age 8 in the rear compared with passengers in the right front seat (RR=0.27, 95% CI 0.12-0.58 for 0-3 years, RR=0.55, 95% CI 0.30-0.98 for 4-8 years) but was higher for restrained 9-12-year-old children (RR=1.83, 95% CI 1.18-2.84). There was no evidence for a difference in risk of death in the rear vs. front seat for occupants ages 13-54, but there was some evidence for an increased relative risk of death for adults age 55 and older in the rear vs. passengers in the right front seat (RR=1.41, 95% CI 0.94-2.13), though we could not exclude the possibility of no difference. After controlling for occupant age and gender, the relative risk of death for restrained rear row occupants was significantly higher than that of front seat occupants in model year 2007 and newer vehicles and significantly higher in rear and right side impact crashes.

CONCLUSIONS

Results of this study extend prior research on the relative safety of the rear seat compared with the front by examining a more contemporary fleet of vehicles. The rear row is primarily occupied by children and adolescents, but the variable relative risk of death in the rear compared with the front seat for occupants of different age groups highlights the challenges in providing optimal protection to a wide range of rear seat occupants. Findings of an elevated risk of death for rear row occupants, as compared with front row passengers, in the newest model year vehicles provides further evidence that rear seat safety is not keeping pace with advances in the front seat.

Predictors of rear seat belt use among U.S. adults, 2012

INTRODUCTION

Seat belt use reduces the risk of injuries and fatalities among motor vehicle occupants in a crash, but belt use in rear seating positions is consistently lower than front seating positions. Knowledge is limited concerning factors associated with seat belt use among adult rear seat passengers.

METHODS

Data from the 2012 ConsumerStyles survey were used to calculate weighted percentages of self-reported rear seat belt use by demographic characteristics and type of rear seat belt use enforcement. Multivariable regression was used to calculate prevalence ratios for rear seat belt use, adjusting for person-, household- and geographic-level demographic variables as well as for type of seat belt law in place in the state.

RESULTS

Rear seat belt use varied by age, race, geographic region, metropolitan status, and type of enforcement. Multivariable regression showed that respondents living in states with primary (Adjusted Prevalence Ratio (APR): 1.23) and secondary (APR: 1.11) rear seat belt use enforcement laws were significantly more likely to report always wearing a seat belt in the rear seat compared with those living in a state with no rear seat belt use enforcement law.

CONCLUSIONS AND PRACTICAL APPLICATIONS

Several factors were associated with self-reported seat belt use in rear seating positions. Evidence suggests that primary enforcement covering all seating positions is an effective intervention that can be employed to increase seat belt use and in turn prevent motor vehicle injuries to rear-seated occupants.

Factors associated with mortality in rear-seated adult passengers involved in fatal motor vehicle crashes on US roadways

BACKGROUND

Recent efforts to pass rear seat belt laws for adults have been hampered by large gaps in the scientific literature. This study examines driver, vehicle, crash, and passenger characteristics associated with mortality in rear-seated adult passengers.

METHODS

The Fatality Analysis Reporting System (FARS) 2010 to 2011 was used to examine motor vehicle occupant mortality in rear-seated adult passengers 18 years and older. Side crash vehicle safety ratings were assessed in a subset analysis of vehicles struck on the same side as the rear-seated passenger. Multilevel logistic regression models used SAS GLIMMIX.

RESULTS

Of the 7,229 rear-seated adult passengers, 2,091 (28.9%) died. Multivariable predictors of increased mortality were advancing passenger age, younger driver age, excessive speed, ejection, being unbelted, rear impact, and same-side crash. Belt use was associated with a 67.0% reduction in total mortality. Despite this, belt wearing was low (48.1%) and differed by seating position, with less than one third of middle-seated passengers belted. Multivariable analysis showed mortality to be nearly three times higher in same-side crashes than other impact locations (odds ratio (OR) = 2.76, 2.22, 3.44). In a multivariable subpopulation analysis of same-side crashes, right-seated passengers had an increased mortality (52.7% vs. 43.2%, p < 0.01) compared to left-seated passengers (OR = 1.55, 1.02, 2.36). Vehicle side crash safety ratings, available for 27.7% (n = 172) of same-side crashes, were not predictive of mortality.

CONCLUSIONS

Except for same-side crashes, seat belts were associated with significantly lowered mortality. Despite this, seat belt wearing was low and represents one of several areas where further improvements in mortality might be realized.

A simulation study on the efficacy of advanced belt restraints to mitigate the effects of obesity for rear-seat occupant protection in frontal crashes

OBJECTIVE

Recent field data analyses have shown that the safety advantages of rear seats relative to the front seats have decreased in newer vehicles. Separately, the risks of certain injuries have been found to be higher for obese occupants. The objective of this study is to investigate the effects of advanced belt features on the protection of rear-seat occupants with a range of body mass index (BMI) in frontal crashes.

METHODS

Whole-body finite element human models with 4 BMI levels (25, 30, 35, and 40 kg/m2) developed previously were used in this study. A total of 52 frontal crash simulations were conducted, including 4 simulations with a standard rear-seat, 3-point belt and 48 simulations with advanced belt features. The parameters varied in the simulations included BMI, load limit, anchor pretensioner, and lap belt routing relative to the pelvis. The injury measurements analyzed in this study included head and hip excursions, normalized chest deflection, and torso angle (defined as the angle between the hip-shoulder line and the vertical direction). Analyses of covariance were used to test the significance (P <.05) of the results.

RESULTS

Higher BMI was associated with greater head and hip excursions and larger normalized chest deflection. Higher belt routing increased the hip excursion and torso angle, which indicates a higher submarining risk, whereas the anchor pretensioner reduced hip excursion and torso angle. Lower load limits decreased the normalized chest deflection but increased the head excursion. Normalized chest deflection had a positive correlation with maximum torso angle. Occupants with higher BMI have to use higher load limits to reach head excursions similar to those in lower BMI occupants.

DISCUSSION AND CONCLUSION

The simulation results suggest that optimizing load limiter and adding pretensioner(s) can reduce injury risks associated with obesity, but conflicting effects on head and chest injuries were observed. This study demonstrated the feasibility and importance of using human models to investigate protection for occupants with various BMI levels. A seat belt system capable of adapting to occupant size and body shape will improve protection for obese occupants in rear seats.

Effectiveness of cable barriers, guardrails, and concrete barrier walls in reducing the risk of injury

Roadway departure crashes tend to be severe, especially when the roadside exposes the occupants of errant vehicles to excessive injury hazards. As a cost-effective method when the clear zone width is insufficient, road barriers are often installed to prevent errant vehicles from colliding with dangerous obstacles or traversing steep slopes. This paper focuses on the safety performance of road barriers in Indiana in reducing the risk of injury. The objective of the study presented here is to compare the risk of injury among different hazardous events faced by an occupant in a single-vehicle crash. The studied hazardous events include rolling over, striking three types of barriers (guardrails, concrete barrier walls, and cable barriers) with different barrier offsets to the edge of the travelled way, and striking various roadside objects. A total of 2124 single-vehicle crashes (3257 occupants) that occurred between 2008 and 2012 on 517 pair-matched homogeneous barrier and non-barrier segments were analyzed. A binary logistic regression model with mixed effects was estimated for vehicle occupants. The segment pairing process and the use of random effects were able to handle the commonality within the same segment pair as well as the heterogeneity across segment pairs. The modeling results revealed that hitting a barrier is associated with lower risk of injury than a high-hazard event (hitting a pole, rollover, etc.). The odds of injury are reduced by 39% for median concrete barrier walls offset 15-18ft from the travelled way, reduced by 65% for a guardrail face offset 5-55ft, reduced by 85% for near-side median cable barriers (offset between 10ft and 29ft), and reduced by 78% with far-side median cable barriers (offset at least 30ft). Comparing different types of barriers is useful where some types of barriers can be used alternatively. This study found that the odds of injury are 43% lower when striking a guardrail instead of a median concrete barrier offset 15-18ft and 65% lower when striking a median concrete barrier offset 7-14ft. The odds of injury when striking a near-side median cable barrier is 57% lower than the odds for a guardrail face. This reduction for a far side median cable barrier is 37%. Thus, a guardrail should be preferred over a concrete wall and a cable barrier should be preferred over a guardrail where the road and traffic conditions allow. In the light of the results, installing median cable barriers on both sides of the median to reduce their lateral offset is beneficial for safety. The study also found that the unexplained heterogeneity across vehicles is much larger than it was across matched segment pairs.

High strength steels, stiffness of vehicle front-end structure, and risk of injury to rear seat occupants

Previous research has shown that rear seat occupant protection has decreased over model years, and front-end stiffness is a possible factor causing this trend. In this research, the effects of a change in stiffness on protection of rear seat occupants in frontal crashes were investigated. The stiffness was adjusted by using higher strength steels (DP and TRIP), or thicker metal sheets. Finite element simulations were performed, using an LS Dyna vehicle model coupled with a MADYMO dummy. Simulation results showed that an increase in stiffness, to the extent it happened in recent model years, can increase the risk of AIS3+ head injuries from 4.8% in the original model (with a stiffness of 1,000 N/mm) to 24.2% in a modified model (with a stiffness of 2,356 N/mm). The simulations also showed an increased risk of chest injury from 9.1% in the original model to 11.8% in the modified model. Distribution of injuries from real world accident data confirms the findings of the simulations.

Assessment of vehicle and restraint design changes for mitigating rear seat occupant injuries

OBJECTIVE

Investigate the combined effects of belt geometry, seat substructure, and seat belt pretensioners and load limiters on rear seat occupant injury risk.

METHODS

An instrumented Hybrid III 5th percentile adult female dummy was subjected to simulated frontal impacts (Δv = 45.8 km/h, peak acceleration = 27.1 g). Testing was conducted on a rear seat of a typical family sedan with modifications allowing for adjustment in upper anchorage position, mounting of an antisubmarining seat pan, and the use of seat belt pretensioners with load limiters.

RESULTS

Dummy seated posture had the strongest effect on submarining. Seat belt pretensioners with load limiters reduced head and femur excursion and decreased chest injury measurements but did not prevent submarining. The antisubmarining seat pan, on the other hand, prevented submarining in one case but could not prevent submarining with the dummy in a slouched posture. Upper anchorage position resulting in poor belt geometry was shown to increase both chest injury measures and submarining.

CONCLUSIONS

The results from this study demonstrate the importance of an upright seated posture and the potential benefits of including adjustable upper anchorages to allow good sash belt fit, antisubmarining seat pans, belt buckles positioned near the seat bight, and seat belts with pretensioners and load limiters for rear seat occupants. These data can be used to inform the design of a system of restraints to reduce injuries to rear seat occupants.

Hospitalizations and fatalities in crashes with light trucks

OBJECTIVE

This study examined 2-car crashes including one passenger car and one light truck (van, minivan, pickup truck, or sport utility vehicle) and investigated the likelihood of hospitalization, hospitalization charges, and the likelihood of fatality of an occupant by vehicle type differentiating between passengers and drivers.

METHODS

We used unique data from Minnesota's Crash Outcome Data Evaluation System (CODES) linked with hospital discharge data from 2004 to 2005. We focused on police-reported crashes that involved 2 vehicles, one car and one light truck. First, we estimated models to predict the likelihood of hospitalization. Next, we estimated models to predict hospitalization charges among the hospitalized. Finally, we modeled the likelihood of fatality. In all models, we distinguished between the 2 vehicle types and controlled for a broad range of occupant, crash, and vehicle characteristics. We estimated separate models for passengers and drivers.

RESULTS

We found that in a crash between a car and a light truck, drivers of light trucks were less likely to be hospitalized (odds ratio [OR] = 64%; 95% confidence interval [CI], 59-70%) and killed (OR = 35%; 95% CI, 18-68%) relative to the drivers of cars. Similarly, passengers of light trucks had a lower likelihood of hospitalization (OR = 66%; 95% CI, 57-77%) and fatality (OR = 14%; 95% CI, 3-54%) relative to the passengers of cars. Among hospitalized occupants, we did not find statistically significant differences in hospital charges between light truck drivers and car drivers, but hospital charges for hospitalized light truck passengers were 59% (95% CI, 40-87%) of the hospital charges of hospitalized car passengers.

CONCLUSIONS

Though previous studies have shown high fatality costs associated with light trucks, this study is the first to explore the hospitalization costs associated with these vehicles. The existing traffic liability systems (tort or no-fault systems) likely fail to fully make light trucks accountable for costs they impose on other cars, pedestrians, and other road occupants. Our findings suggest the importance of a close examination of a broad range of cost implications even beyond hospitalization and fatality costs to evaluate the optimal amount of corrective taxes or other corrective policies in future research. Supplemental materials are available for this article. Go to the publisher's online edition of Traffic Injury Prevention to view the supplemental file.

Injury severity and seating position in accidents with German EMS helicopters

INTRODUCTION

Accident rates and fatality rates for Helicopter Emergency Medical Service (HEMS) missions have been investigated recently, but none of these studies considered the influence of the seating position in the helicopter. The aim of the present descriptive and observational study was to analyze injury severity depending on the seating position during HEMS accidents in Germany.

MATERIAL AND METHODS

Data from the German Federal Agency for Flight Accident Investigation was gathered for a period of 40 years (from 1970 to 2009). The seating position in the aircraft during the accident and the resulting injury severity (i.e., 1=no; 2=slight; 3=severe; and 4=fatal) were recorded. Injury severity was compared using the Fisher's exact test. P values <0.05 were considered statistically significant.

RESULTS

A total of n=99 accidents were investigated (n=61 accidents did not lead to any injuries in the occupants, n=7 accidents resulted in minor, and n=6 in severe injuries, and lethal injuries resulted from n=15 accidents). The occupant in the "patient" position was most likely to suffer from deadly injuries (44.9%), followed by the HEMS crew member rear seat (25.0%), compared to lower lethality rates in the other seating positions (9.4-11.2%). Sitting on the HEMS crew member rear seat also was associated with the highest percentage of severe and minor injuries (12.5% each).

CONCLUSIONS

In HEMS accidents, the patients' position and the HEMS crew member rear seat were found to be at the highest risk for fatal or severe injuries. These results support the urgent requirement of a large international data base for HEMS accidents as a basis for further studies to improve the safety in HEMS missions.

Child and youth traffic-related injuries: use of a trauma registry to identify priorities for prevention in the United Arab Emirates

OBJECTIVE

Traffic-related injuries are the main cause of death during childhood and youth in the United Arab Emirates (UAE), use of safety restraints by citizens is uncommon, rollovers are frequent, and current legislation does not protect rear-seat occupants. Because little was known about the circumstances of hospitalizations for traffic injuries to guide prevention, a trauma registry was used to assess causes and determinants for traffic-related injuries during childhood and youth (<19 years) and its value for prevention.

METHODS

One hundred ninety-three children and youth with traffic injuries were admitted for more than 24 h at surgical wards of the main trauma hospital in the Al-Ain region during a 36-month period (2003-2006). Injuries were analyzed by age, nationality, road user and vehicle types, severity, anatomical region, and the presence of head injury using Injury Severity Scores (ISS) and the Abbreviated Injury Scale (AIS).

RESULTS

Traffic injuries represented 40 percent (n = 193) of injuries to 0- to 19-year-olds, followed by falls (39 percent). Among 15- to 19-year-olds, who accounted for 46 percent of child and youth victims, the incidence was 150/100,000 person years, compared to an incidence of 15 to 51 for younger age groups. Overall, 53 percent were vehicle occupants, 23 percent were pedestrians, 14 percent were bicyclists, 6 percent were motorcyclists, with 4 percent other. The ratio of male-to-female victims was 6.7:1; for drivers it was 33:0; and for pedestrians, bicyclists, and motorcyclists it was between 10:1 and 12:1; injured females were mainly rear-seat passengers and the male: female ratio was 1.4:1. Seventy-one percent of pedestrians were ≤9 years old. Although the ratio of UAE children to foreign children was estimated at 0.7:1 in the community, 58 percent of the injured were UAE citizens. The ratio of injured UAE: non-UAE citizens was 1.4:1 overall but 5.6:1 for drivers and 4.5:1 for motorcyclists. Forty-one percent of citizens were injured in 4-wheel drive sport utility vehicles compared to 13 percent of non-citizens. Head injuries occurred in 68 percent of vehicle occupants and 51 percent of nonoccupants, with AIS ≥ 3 injuries in 23 percent of occupants and 26 percent of nonoccupants. Sixty-seven percent of rear occupants had head injuries.

CONCLUSIONS

Male drivers and vulnerable road users were at an unusually high risk relative to females. A relatively high frequency of traffic-related head injuries among UAE children and youth, including rear-seat passengers and other vehicle occupants, suggests that considerable preventable morbidity is associated with nonuse of safety restraints and/or other factors such as excess speed and rollovers of 4-wheel drive vehicles. Trauma registries can be useful for prevention; inclusion of data on safety restraints and helmet use by road user type is essential.

Factors related to seatbelt-wearing among rear-seat passengers in Malaysia

The benefit of wearing a rear seatbelt in reducing the risk of motor vehicle crash-related fatalities and injuries has been well documented in previous studies. Wearing a seatbelt not only reduces the risk of injury to rear-seat passengers, but also reduces the risk of injury to front-seat occupant who could be crushed by unbelted rear-seat passengers in a motor vehicle crash. Despite the benefits of wearing a rear seatbelt, its rate of use in Malaysia is generally low. The objective of this study was to identify factors that are associated with the wearing of a seatbelt among rear-seat passengers in Malaysia. Multinomial logistic regression analysis of the results of a questionnaire survey of 1651 rear-seat passengers revealed that rear-seat passengers who were younger, male, single and less educated and who had a perception of a low level of legislation enforcement, a lower risk-aversion and less driving experience (only for passengers who are also drivers) were less likely to wear a rear seatbelt. There was also a significant positive correlation between driver seatbelt and rear seatbelt-wearing behaviour. This implies that, in regards to seatbelt-wearing behaviour, drivers are more likely to adopt the same seatbelt-wearing behaviour when travelling as rear-seat passengers as they do when driving. These findings are crucial to the development of new interventions to increase the compliance rate of wearing a rear seatbelt.

Factors affecting hospital admission and recovery stay duration of in-patient motor victims in Spain

Hospital expenses are a major cost driver of healthcare systems in Europe, with motor injuries being the leading mechanism of hospitalizations. This paper investigates the injury characteristics which explain the hospitalization of victims of traffic accidents that took place in Spain. Using a motor insurance database with 16,081 observations a generalized Tobit regression model is applied to analyse the factors that influence both the likelihood of being admitted to hospital after a motor collision and the length of hospital stay in the event of admission. The consistency of Tobit estimates relies on the normality of perturbation terms. Here a semi-parametric regression model was fitted to test the consistency of estimates, concluding that a normal distribution of errors cannot be rejected. Among other results, it was found that older men with fractures and injuries located in the head and lower torso are more likely to be hospitalized after the collision, and that they also have a longer expected length of hospital recovery stay.

Grandparents and child passenger safety

PURPOSE

This study compares child passenger safety (CPS) practices of grandparents versus parents and determines grandparents' opinions on car safety seats (CSS), barriers to use, and ways to transport grandchildren safely.

METHODS

Observational surveys were conducted on a convenience sample of drivers transporting children younger than sixteen years at 25 locations by certified child passenger safety technicians observing children in motor vehicles and recorded use of child passenger restraints. The drivers were surveyed on their knowledge, attitudes, beliefs, and practices regarding CPS. Data from drivers identifying themselves as grandparents were analyzed; also, three grandparent focus groups provided opinions on CPS practices.

RESULTS

During the study 1758 parents transporting 2713 children and 284 grandparents transporting 391 grandchildren were included. While most drivers were restrained and used child occupant restraints, almost 25% of parents and grandparents chose the incorrect seat to transport the child, and greater than 68% had at least one harness error. Grandparents were more likely to have looser lower anchor straps or seat belts and have children younger than thirteen years in the front seat. The focus group-grandparents had a favorable attitude toward CSS. Grandparents acknowledged the need for CSS but opined that CSS were difficult to use. Physical barriers included arthritis, back pain, mobility, decreased strength, and vision problems.

CONCLUSIONS

Grandparents and parents were equally likely to use CSS and choose correct seats. Compared to parents, grandparents were more likely to travel with their grandchildren with CSS installed with looser harnesses or an installed CSS with looser seat belt or lower anchors. Additionally, grandparents were more likely to have a child younger than thirteen years in the front seat. The use of community resources such as permanent fitting stations could help grandparents improve a grandchild's travel safety.

Risk factors for child and adolescent occupants, bicyclists, and pedestrians in motorized vehicle collisions

OBJECTIVE

The aim was to use similar population data to examine the relative risk of collision injury among children of different ages and adolescents involved in various collision types and to elucidate the possible risk factors related to road collisions involving children and adolescents in a large, 2-wheeled vehicle environment.

METHODS

We used data from a society with a large population of motorcyclists to examine the relative risk of injury among children and adolescents aged 0 to 6, 7 to 9, 10 to 12, 13 to 15, and 16 to 17 years old who were involved in single motorized vehicle, multiple motorized vehicle, bicycle-to-vehicle, and pedestrian-to-vehicle collisions. Police reports for 73,232 collision injuries between the years 2003 and 2009 were analyzed using multicategory logit models of the 4 collision types.

RESULTS

Young (particularly 0- to 6-year-old) child bicyclists and pedestrians were the most sensitive to several factors. In collisions, young child bicyclists making U-turns or being struck by forward-moving or right-turning motorized vehicles, on local roads, during the daytime, or at locations without traffic signals had the greatest risk of injury. Similarly, young child pedestrians running, during the daytime, or at locations without traffic signals had a significant risk of injury. After controlling for other factors, we found that 4-wheeled motorized vehicles, not motorcycles, presented a higher risk for injury to child passengers, bicyclists, and pedestrians.

CONCLUSIONS

The risk of collision injury varied for the different groups of children in the 4 collision types. To reduce the risk of injury for young children, we recommend the development of road-crossing training tools for parents. In addition, the behaviors of children should be taken into consideration when developing in-vehicle assistance systems.

Epidemiology of motor vehicle crashes in Utah

OBJECTIVES

This study describes the frequency and pattern of vehicle crashes and safety belt use in Utah; the proportion of vehicle crashes involving safety belt use, alcohol, and fatigue; and the influence these factors and others have on emergency room visits or hospital admissions and on the severity of the outcome.

METHODS

Data were obtained from the Utah Department of Transportation, Division of Traffic and Safety, from 1999 through 2005. Motor vehicle crash (MVC) data were linked to statewide hospital admission (inpatient) and emergency department (ED) records.

RESULTS

The trend in rates of crashes significantly decreased for both males and females, with rates of crashes involving alcohol decreasing for males but increasing for females and rates of crashes involving fatigue remaining constant for males and females over the study period. Drivers not wearing a safety belt or intoxicated or fatigued were significantly more likely to have contributed to the crash, visit the emergency room, be admitted to the hospital, and experience severe injury or death. Drivers in crashes who were intoxicated or fatigued were significantly less likely to be wearing a safety belt. When a safety belt was worn at the time of the crash, sitting in the front seat was safer than in the second or third seats, and sitting on the left side of the vehicle was safer than on the right side or in the middle. However, when a safety belt was not worn at the time of the crash, sitting in the front seat was more likely associated with injury or death than in the second or third seats or sitting in the middle seat.

CONCLUSION

Drivers in crashes who were intoxicated or fatigued were less likely to be wearing a safety belt and more likely to have contributed to the crash and experience serious injury or death. Severity of injury related to seat placement is moderated by safety belt use.

Quantification method analysis of the relationship between occupant injury and environmental factors in traffic accidents

Injury analysis following a vehicle crash is one of the most important research areas. However, most injury analyses have focused on one-dimensional injury variables, such as the AIS (Abbreviated Injury Scale) or the IIS (Injury Impairment Scale), at a time in relation to various traffic accident factors. However, these studies cannot reflect the various injury phenomena that appear simultaneously. In this paper, we apply quantification method II to the NASS (National Automotive Sampling System) CDS (Crashworthiness Data System) to find the relationship between the categorical injury phenomena, such as the injury scale, injury position, and injury type, and the various traffic accident condition factors, such as speed, collision direction, vehicle type, and seat position. Our empirical analysis indicated the importance of safety devices, such as restraint equipment and airbags. In addition, we found that narrow impact, ejection, air bag deployment, and higher speed are associated with more severe than minor injury to the thigh, ankle, and leg in terms of dislocation, abrasion, or laceration.

A matched-cohort analysis of belted front and rear seat occupants in newer and older model vehicles shows that gains in front occupant safety have outpaced gains for rear seat occupants

Previous studies have suggested that rear seat occupants are at lower risk of serious injury and death in crashes. However, over the last 10-15 years there have been significant changes in front seat safety systems. The aim of this study was to determine whether there is still a benefit for rear seated occupants compared to front seat occupants. A matched-cohort approach, using data on restrained occupants from the US National Automotive Sampling System (data years 1993-2007), was adopted. Conditional poisson regression modeling was used to evaluate the relative risk of AIS3+ injury in front (passenger and driver) and rear seat occupants, in vehicles of model year 1990-1996 compared to newer vehicles. Occupant age, belt type, and intrusion were additional variables in the model. The relative risk of AIS3+ injury for front and rear occupants was influenced by age and model year. For those aged 16-50 years in older vehicles, the front and rear seat offered similar levels of protection (RR=1.14, CI=1.09-1.19), however in newer model vehicles (1997-2007), the rear seat carried a higher risk of injury (RR=1.98, CI=1.90-2.06). For adults over 50 years, the rear seat carried a higher risk in both older and newer vehicles, and for 9-15 year olds, the rear seat carried a lower risk. These findings suggest that safety for front seat occupants has improved over the last decade, to the point where, for occupants over 15 years of age, the front seat is safer than the rear seat. While the benefit of rear seating for children aged 9-15 years has decreased over time, they are still at lower risk in the rear seat.

Risk factors for urban road traffic injuries in Hangzhou, China

OBJECTIVE

To investigate factors that most influence urban road traffic injuries (RTI) mortality and morbidity.

METHODS

The study used linked police and hospital records of RTI patients in the city of Hangzhou during the 3-year period 2004-2006. Three RTI outcome groups were included: (1) fatally injured; (2) severely injured; and (3) mildly injured persons.

RESULTS

High risks for fatal road traffic accidents (RTA) were found on urban links, over weekend, during night hours, in male drivers who drove old vehicles without using seat belts, and at exceeding speeds, or with night time accidents and bad weather condition. In case of higher risk for all urban road users on urban junctions, the numbers on mildly injury cases were increasing. The highest combined risk for dying or being severely injured was found in male drivers driving at excessive speed, on urban links, and with night time accidents.

CONCLUSIONS

Intensifying safety education of motor vehicle drivers, enhancing traffic management and keeping balance of "person-vehicle-road" system will greatly reduce the urban traffic accidents and casualties.

The safest seat: effect of seating position on occupant mortality

INTRODUCTION

This study investigated the survival rates of occupants of passenger cars involved in a fatal crash between 2000 and 2003.

METHODS

The information from every fatal crash in the United States between 2000 and 2003 was analyzed. Variables such as seat position, point of impact, rollover, restraint use, vehicle type, vehicle weight, occupant age, and injury severity were extracted from the Fatality Analysis Reporting System (FARS). Univariate and a full logistic multivariate model analyses were performed.

RESULTS

The data show that the rear middle seat is safer than any other occupant position when involved in a fatal crash. Overall, the rear (2(nd) row) seating positions have a 29.1% (Univariate Analysis, p<.0001, OR 1.29, 95% CI 1.22 - 1.37) increased odds of survival over the first row seating positions and the rear middle seat has a 25% (Univariate Analysis, p<.0001, OR 1.25, 95% CI 1.17 - 1.34) increased odds of survival over the other rear seat positions. After correcting for potential confounders, occupants of the rear middle seat have a 13% (Logistic Regression, p<.001, 95% CI 1.02 - 1.26) increased chance of survival when involved in a crash with a fatality than occupants in other rear seats.

CONCLUSION

This study has shown that the safest position for any occupant involved in a motor-vehicle crash is the rear middle seat.

IMPACT ON INDUSTRY

The results of this research may impact how automobile manufacturers look at future rear middle seat designs. If the rear seat was to be designed exactly like its outboard counterparts (headrest, armrests, lap and shoulder belt, etc.) people may choose to sit on it more often rather than waiting to use it out of necessity due to multiple rear seat occupants.

Rear seat safer: seating position, restraint use and injuries in children in traffic crashes in Victoria, Australia

Car crashes are a major cause of death and serious injury to children but most analyses of risk are based on US data. The Australian context is different in at least three ways: (1) the proportion of passenger-side airbags, a potential risk to children in front seats, is much lower; (2) unlike in the US, Australian airbags are designed to work with restrained passengers; (3) restraint use for children 0-12 years is high (>90%). Official data drawn from Victorian crash records (n=30,631) were used to calculate relative risks of death or serious injury for children (0-3 years, 4-7 years; 8-12 years) traveling in passenger cars during 1993-1998 and 1999-2004. Over 90% were reportedly wearing a restraint, and 20% were traveling in the front seat. For children under 4 years traveling in the front seat, the relative risk of death was twice as great as when traveling in the rear, and that of serious injury was 60% greater. The relative risk of death whilst traveling in the front seat was almost four times greater for children aged under 1 year. We suggest that serious consideration should be given to mandating rear seating for children, particularly those aged 4 and under.

Passenger seating position and the risk of passenger death in traffic crashes: a matched cohort study

OBJECTIVE

To estimate the association of passenger seating position with the risk of death for passengers in traffic crashes.

DESIGN, SETTING, PARTICIPANTS

Matched cohort analysis of data from the National Highway Traffic Safety Administration Fatality Analysis Reporting System regarding 56 644 passengers in 23 308 passenger cars, light trucks, vans, and sport utility vehicles that crashed during 1990-2001.

MAIN OUTCOME MEASURE

The adjusted risk ratio (aRR) for death of a rear seat passenger compared with a front seat passenger within 30 days of a crash.

RESULTS

The aRR for all passengers in the rear seat in a crash was 0.79 (95% CI 0.77 to 0.82). This estimate varied by age, restraint use, and the presence of a front passenger airbag (p<0.001). For restrained passengers in cars with a front passenger airbag, the aRR was 0.62 (95% CI 0.48 to 0.81) for children 0-12 years, 0.96 (95% CI 0.88 to 1.06) for passengers 13-29 years, 1.03 (95% CI 0.93 to 1.15) for passengers 30-59 years, and 1.06 (95% CI 0.90 to 1.26) for passengers 60 years or older. The rear seat was associated with more protection in cars without front airbags and more protection for unrestrained passengers compared with restrained passengers.

CONCLUSIONS

Previous studies have reported that the rear seat was safer for persons of all ages; thus seating a young child in the rear has often meant that older children and adults had to assume an increased risk of death by sitting in the front. These results suggest that when front passenger airbags are present and passengers are restrained, putting adults in front and children in back enhances child safety without sacrificing adult safety.

Individual factors affecting the risk of death for rear-seated passengers in road crashes

We studied the effect of age, gender, use of restraint systems and seat position on the risk of death for rear-seated passengers of cars involved in road crashes. The data source was the Spanish register of traffic crashes with victims compiled by the Government's General Traffic Directorate. Data for crashes recorded from 1993 to 2002, inclusive, were studied. We used a matched cohort design to analyze all 5260 rear-seated passengers in vehicles occupied by two or three rear-seated passengers for accidents in which at least one of these passengers was killed. Conditional Poisson regression with death as the dependent variable was used. An increased risk of death was observed for females and children aged <3 years. For passengers aged 25 years and older, the risk increased with age. The use of restraint systems and central and right-side seats was associated with a lower risk. These results should be considered in research focused on passenger fragility and strategies to prevent injury and death.

Assessing the relative risk of severe injury in automotive crashes for older female occupants

A logistic regression model was used in the prediction of injury severity for individuals who are involved in a vehicular crash. The model identified females and older occupants (segmented by age 55-74, and 75 and older) as having a significantly higher risk of severe injuries in a crash. Further, interactions of older females with other factors, such as occupant seat position, crash type, and environmental factors were also shown to significantly impact the relative risk of a severe injury. This study revealed that females 75 years and older had the lowest odds of injury among all female occupants studied (OR=1.16) while females between 55 and 74 years old have higher risk of severe injuries (OR=1.74). All older females (55 and older) were at greater risk for head-on, side-impact and rear-end collisions. Seatbelt use reduced severe injuries for females in this age group, but not to the same extent as the rest of the population studied. Additionally, crashes in severe weather, which were less likely to result in severe injuries for the general population, increased the risk of severe injuries to females that were 55 and older. Among occupants of light trucks, sport utility vehicles and vans, older females were less likely than others to be severely injured. In this case, older females appear better off in vehicles which are larger and protect better in severe crashes. This research demonstrates that circumstances surrounding a crash greatly impact the severity of injuries sustained by older female occupants.

The effect of seating location on the injury of properly restrained children in child safety seats

Properly restrained child passengers in the National Automotive Sampling System (NASS), General Estimates System (GES), were studied for the effect of seating position on the risk of injury. The analysis focused on children seated in a child safety seat in a rear seat location. A multiple logistic regression model was used to assess whether the center rear seat is a safer seating position than either of the outboard rear seats. Standard errors for the odds ratios (ORs) of injury for several correlates of injury including seating position were obtained using a jackknife procedure. This analysis of the data showed that the center rear seat is not a safer seating position than either of the outboard rear seats in terms of odds of injury (left seat OR = 0.88, 95% CI = 0.73-1.03; right seat OR = 1.03, 95% CI = 0.85-1.20). These results do not agree with those of previous studies that suggested the center rear seat is the safest position for parents to place a child safety seat.