The safest seat: effect of seating position on occupant mortality

Demographic and injury trends for car crash casualties hospitalized in Level I Trauma centers over two decades: data from the National Trauma Registry

BACKGROUND

During the past two decades, there have been many changes in automotive and medical technologies, road infrastructure, trauma systems, and demographic changes which may have influenced injury outcomes. The aim of this study was to examine injury trends among traffic casualties, specifically private car occupants, hospitalized in Level I Trauma Centers (TC).

METHODS

A retrospective cohort study was performed based on data from the Israel National Trauma Registry. The data included occupants of private cars hospitalized in all six Level I TC due to a traffic collision related injury between January 1, 1998 and December 31, 2019. Demographic, injury and hospitalization characteristics and in-hospital mortality were analyzed. Chi-squared (X2) test, multivariable logistic regression models and Spearman's rank correlation were used to analyze injury data and trends.

RESULTS

During the study period, 21,173 private car occupants (14,078 drivers, 4,527 front passengers, and 2,568 rear passengers) were hospitalized due to a traffic crash. The percentage of females hospitalized due to a car crash increased from 37.7% in 1998 to 53.7% in 2019. Over a twofold increase in hospitalizations among older adult drivers (ages 65+) was observed, from 6.5% in 1998 to 15.7% in 2018 and 12.6% in 2019. While no increase was observed for severe traumatic brain injury, a statistically significant increase in severe abdominal and thoracic injuries was observed among the non-Jewish population along with a constant decrease in in-hospital mortality.

CONCLUSIONS

This study provides interesting findings regarding injury and demographic trends among car occupants during the past two decades. Mortality among private car occupant casualties decreased during the study period, however an increase in serious abdominal and thoracic injuries was identified. The results should be used to design and implement policies and interventions for reducing injury and disability among car occupants.

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.

Characteristics of Traffic Accidents on Highways: An Analysis Based on Patients Treated at a Regional Trauma Center

Purpose There have been increasing concerns about serious traffic accidents on highways. The purpose of this study was to analyze factors affecting traffic accidents on highways and the severity of the resulting injuries. Methods This retrospective study was conducted at a regional trauma center. We reviewed 594 patients who had been in 114 traffic accidents on highways from January 2018 to June 2020. We collected demographic data, clinical data, accident-related factors, and meteorological data (weather and temperature). Results Environmental risk factors were found to be significantly associated with the incidence of traffic accidents on highways. Injury severity and the death rate were higher in sedans than in any other type of vehicle. Tunnels were the most common location of accidents, accounting for 47 accidents (41.2%) and 269 injured patients (45.3%). The injury severity of individuals riding in the driver’s seat (front seat) was high, regardless of vehicle type. Three meteorological risk factors were found to be significantly associated with traffic accidents: rainy roads (odds ratio [OR] 2.08; 95% confidence interval [CI] 1.84–3.29; p=0.01), icy or snowy roads (OR 5.12; 95% CI 2.88–7.33; p<0.01), and foggy conditions (OR 2.94; 95% CI 2.15–4.03; p<0.05). Conclusions The injury severity of patients was affected by seat position and type of vehicle, and the frequency of accident was affected by the location. The incidence of traffic accidents was strongly influenced by meteorological conditions (rain, snow/ice, and fog).

Analysis of pedestrian-vehicle crash injury severity factors in Colorado 2006-2016

This paper investigates factors associated with the severity of pedestrian outcomes from motor vehicle crashes by analyzing a database of all 13,856 reported pedestrian crashes in Colorado over an 11-year period from 2006 to 2016. A total of 14,391 pedestrians were involved in these crashes, resulting in 612 (4.3%) pedestrian fatalities, 11,576 (80.4%) pedestrian injuries, and 2203 (15.3%) property damage only outcomes. The objective is to analyze crash records, as similarly compiled by other states, to show how lives potentially saved by improved factor levels can be estimated as needed for benefit-cost comparisons of alternative countermeasures. Odds ratios of fatal versus non-fatal pedestrian outcomes are computed both independently (unadjusted) and from logistic regression (adjusted) for each factor level accounting for possible correlations between factors. Also computed are odds ratios for fatal plus incapacitating injuries and odds ratios for just 2011-2016 versus all years. This study found that intersection proximity, lighting condition, vehicle type and speed, pedestrian age, pedestrian impairment, and driver impairment by drugs or alcohol were all significant factors associated with the severity of pedestrian outcomes from motor vehicle crashes. Risk ratios from these odds ratios are used to estimate lives potentially saved by having better factor levels present at the time of these crashes. These estimates reflect the relative magnitudes of benefits that might be achieved by potential countermeasures taking into account the number of cases affected.

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.

Self-reported factors that influence rear seat belt use among adults

INTRODUCTION

While seat belt use among front seat occupants has significantly increased overtime a substantial usage gap still exists between front and back seat occupants. This study aims to identify factors that predict rear seat belt use among adult back seat passengers.

METHODS

We examined data from the 2016 Motor Vehicle Occupant Safety Survey, conducted by the National Highway Traffic Safety Administration, to determine the influence of front seat belt use, support of and belief of rear seat belt use laws, peer perception of seat belt use, nighttime belt use, and demographic factors on self-reported rear seat belt use. Rao-Scott chi-squared tests were used to determine significant associations between self-reported rear belt use and each predictor. Multivariate logistic regression was used to calculate adjusted odds ratios and determine the influence of significant predictors on rear seat belt use. Sampling weights were applied to produce nationally representative estimates; all statistical significance tests accounted for the complex survey design.

RESULTS

Among adults who reported riding in the back seat, 63% reported always using a rear seat belt. Front seat belt use, support and belief of state seat belt laws, nighttime seat belt use, age, and education were significantly associated with rear seat belt use. Multivariate regression results showed that adults who supported rear seat belt laws, reported front seat belt use and believed their state has a rear seat belt law were significantly more likely to report full-time use in the back seat.

CONCLUSIONS

Seat belt laws and front seat belt use had the strongest association with reporting full-time use in the back seat. Practical Applications: Increasing familiarity with existing laws directed towards rear seat belt use as well as increasing awareness about the benefits of seat belts in all seating positions may help improve rear seat belt use.

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.

A comparative analysis of child passenger restraint use in China and the United States

BACKGROUND

Few published studies have examined child passenger safety practices across countries. This study compared the prevalence and associated factors of child passenger restraint use among children, aged 0 to 17 in the state of Iowa in the United States, and the city of Shantou in China.

METHODS

Child restraint use observations were conducted in Iowa and in Shantou in 2012, respectively, among child passengers. Observations in Iowa were conducted at randomly selected gas stations, while in Shantou observations were completed at randomly selected schools or medical clinics. Research observers approached the driver, observed restraint use, and collected brief survey data.

RESULTS

A total of 3049 children from Iowa and 3333 children aged 0 to 17 years from Shantou were observed. For children aged 0 to 3 years, only 0.1% were compliantly restrained in Shantou as compared to 95.9% in Iowa. The proportion of children who were compliantly restrained in Shantou increased with age, but generally decreased with age in Iowa. In Shantou, 36.0% of children aged 0 to 3 were sitting in the front seat as compared to only 1.7% of children of the same age in Iowa. Driver seat belt use was significantly associated with child restraint in both Iowa and Shantou; the association was stronger in Iowa than Shantou for all age groups.

CONCLUSIONS

A significantly higher prevalence of children who were not appropriately restrained was observed in Shantou than in Iowa. Our findings support the need of mandatory child safety restraint use legislation in China.

Side impact motor vehicle crashes: driver, passenger, vehicle and crash characteristics for fatally and nonfatally-injured rear-seated adults

Background

Most studies of rear-seated occupants have focused on or included pediatric occupants which may not translate to adults. This study examines passenger, driver, vehicle and crash characteristics for rear-seated adult occupants involved in side crashes.

Methods

The National Automotive Sampling System General Estimates System (NASS/GES) for calendar years 2011–2014 was used with accompanying weights to examine the occupant, vehicle and crash characteristics associated with injury in rear-seated adults (n = 395,504) involved in a side crash. A weighted subpopulation analysis includes occupants travelling in a vehicle with an IIHS safety rating (n = 39,208), which was used to control for vehicle safety. Statistical analysis used Chi-square tests and multilevel multivariable logistic regression. Unadjusted and adjusted odds ratios (ORs) are reported with 95 % confidence intervals (95 % CIs).

Results

Rear-seated occupants on the same side as the crash impact were more likely to be severely/fatally injured than occupants seated on the opposite side (Multivariable adjusted OR: 2.54, 95 % CI: 2.31–2.79), as were those in angle crashes (Multivariable adjusted OR: 10.85, 95 % CI: 9.24–12.73). Rear-seated occupants of belted drivers were 3.28 times more likely to be belted compared to rear-seated occupants of an unbelted driver. In a subpopulation analysis of all same-side crashes, unrestrained occupants were 5.96 times more likely to be severely/fatally injured compared to restrained occupants.

Conclusion

Restraint use was protective for rear-seated adult occupants involved in side crashes, including those in same-side crashes. Angle and same-side crashes are associated with increased injury severity.

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.

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.

Predicting in-hospital death among patients injured in traffic crashes in Saudi Arabia

INTRODUCTION

Traffic-related injuries are a major cause of premature death in developing countries. Saudi Arabia has struggled with high rates of traffic-related deaths for decades, yet little is known about health outcomes of motor vehicle victims seeking medical care. This study aims to develop and validate a model to predict in-hospital death among patients admitted to a large-urban trauma centre in Saudi Arabia for treatment following traffic-related crashes.

METHODS

The analysis used data from King Abdulaziz Medical City (KAMC) in Riyadh, Saudi Arabia. During the study period 2001-2010, 5325 patients met the inclusion criteria of being injured in traffic crashes and seen in the Emergency Department (ED) and/or admitted to the hospital. Backward stepwise logistic regression, with in-hospital death as the outcome, was performed. Variables with p<0.05 were included in the final model. The Bayesian Information Criterion (BIC) was employed to identify the most parsimonious model. Model discrimination was evaluated by the C-statistic and calibration by the Hosmer-Lemeshow Goodness of Fit statistic. Bootstrapping was used to assess overestimation of model performance and obtain a corrected C-statistic.

RESULTS

457 (8.5%) patients died at some time during their treatment in the ED or hospital. Older age, the Triage-Revised Trauma Scale (T-RTS), and Injury Severity Score were independent risk factors for in-hospital death: T-RTS was best modelled with linear and quadratic terms to capture a flattening of the relationship to death in the more severe range. The model showed excellent discrimination (C-statistic=0.96) and calibration (H-L statistic 4.29 [p>0.05]). Internal bootstrap validation gave similar results (C-statistic=0.96).

CONCLUSIONS

The proposed model can predict in-hospital death accurately. It can facilitate the triage process among injured patients, and identify unexpected deaths in order to address potential pitfalls in the care process. Conversely, by identifying high-risk patients, strategies can be developed to improve trauma care for these patients and reduce case-fatality. This is the first study to develop and validate a model to predict traffic-related mortality in a developing country. Future studies from developing countries can use this study as a reference for case fatality achievable for different risk profiles at a well-equipped trauma centre.

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.

Parents' knowledge, attitude, and use of child restraints, Shantou, China

BACKGROUND

China has not adopted national policies for child safety restraints in cars, although children are increasingly traveling in cars.

OBJECTIVE

To describe child restraint use, and parents' knowledge of and attitude toward child restraint in Shantou, China.

METHODS

An observational study and driver survey on child restraint use was conducted in the Southeast China city of Shantou in 2012. Observational sites included 22 middle schools, 31 primary schools, 24 kindergartens, and 4 hospitals. Drivers were asked about their knowledge of and attitude toward the use of child restraints. In September 2012, multivariate regression was used to evaluate the factors associated with increased child restraint use.

RESULTS

Of 3333 children observed in vehicles, only 22 (0.6%) children were secured in child safety seats or booster seats and 292 (8.7%) children were wearing seatbelts. More than half (n=508, 56.1%) of the infants or toddlers were riding on the laps of adults. Of 1069 drivers who responded to the survey, more than 62% thought it was necessary to use child restraint while traveling in a car. The drivers' higher education status (OR=1.56, 95% CI=1.07, 2.27) and seatbelt use (OR=4.00, 95% CI=2.56, 6.25) were associated with increased child restraint use. Parents (OR=0.55, 95% CI=0.34, 0.88) and male drivers (OR=0.61, 95% CI=0.46, 0.81) had reduced odds of children properly rear-seated.

CONCLUSIONS

Child restraint use is very low in China, although the majority of drivers had positive attitudes about child restraint. These findings indicate that child restraint policies and educational approaches are urgently needed in China.

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.