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

Which is the role of driver- or passengers-sex on the severity of road crashes?

Aim

The aim of the study is to quantify the main ways in which the sex of the driver/occupant of a passenger car affects the severity of road crashes.

Methods

All 171 230 cars occupied by the driver and one or more passengers included in the Spanish Register of Victims of Road Crashes from 2014 to 2020 were included. We designed two cohort studies: In the first one, we estimated the Incidence Rate Ratios (IRR) between the sex of the drivers and the occurrence of any death and/or severe injuries among their passengers. In the second one we estimated the conditioned IRR between the sex of the occupants of the same car and their risk of death and/or severe injuries. We used fixed Poisson models to obtain IRR estimates, crude and adjusted by individual- environment- and vehicle-related variables.

Results

A consistent inverse relationship between driver's female sex and passenger's severity was found, (IRR 0.72, 95 % CI 0.68-0.77), stronger for single crashes (IRR 0.67, 95 % CI 0.60-0.65). The magnitude decreased after adjusting for vehicle- and environment-related variables (IRR 0.82, 95 % CI 0.73-0.92). In the second study, the risk of death or hospitalization was higher for occupants of female sex (IRR 1.23, 95 % CI 1.17-1.30).

Conclusions

The risk of death or severe injuries among passengers of cars involved in single crashes is lower for female drivers, probably due to safer driving. On the contrary, in similar crashes, the risk of injuries leading to hospitalization is higher for females.

A bivariate probit analysis of child passenger's sitting behaviour and restraint use in motor vehicle

Motor vehicle injuries are a leading cause of death among children worldwide, though many of these deaths are preventable. Buckling young children in age- and size-appropriate car seats, booster seats, or seat belts and also seating them in appropriate position can lead to a significant reduction of serious and fatal injuries. This study investigated sitting behaviour and restraint use among child passengers through cross-sectional observational surveys conducted in Kumasi, Ghana. A bivariate probit model was developed for simultaneous determination of the contributing factors influencing child passenger's sitting behaviour and restraint use. The results showed that 26% of the child passengers observed were occupying the front seat and the prevalence rate of restraint use was 4.5%. The developed bivariate probit model clearly highlights the existence of interrelationship between child passenger's sitting position and restraint use. The key factors simultaneously influencing child passenger's sitting position and restraint use include vehicle type, driver's gender, driver's belt use, child's age, and the presence of other child or adult passenger. Furthermore, time of day and day of week also influence child passenger sitting behaviour but not their restraint use. These findings provide insight for better understanding of child transporting practices and the contributing factors influencing their sitting behaviour and restraint use. The findings also highlight the need for policy makers to design effective countermeasures to promote rear sitting and restraint use among child passengers.

Occupants' seatbelt use are related to vehicle type and usage on a Ghanaian university campus

Seat belt use does not only save lives but prevents the severity of injuries in road traffic crashes (RTCs). Vehicle type and usage have been found to influence the use of seat belt in cities like Kumasi, the host of Kwame Nkrumah University of Science and Technology (KNUST) campus. This paper presents a study on an un-obstructive survey of seat belt use by vehicle occupants entering and leaving KNUST campus through the four entrances from 7 to 9 am and 3 to 5 pm on five weekdays. A total of 5489 vehicles with 9542 occupants comprising 5489 drivers, front-right and first back seat and second back seat passengers were observed. The majority of the private and SUV drivers used seat belts. Meanwhile, almost all the commercial drivers did not use seat belts. There is a statistically significant relationship between vehicle type and use and the use of seat belt in KNUST.

Elderly road collision injury outcomes associated with seat positions and seatbelt use in a rapidly aging society-A case study in South Korea

INTRODUCTION

Aging has long been regarded as one of the most critical factors affecting crash injury outcomes. In South Korea, where the elderly population is projected to reach 35.9% by 2050, the implications of an increasing number of elderly vehicle users on road safety are evident. In this research, the confounding effect of occupant age in a vehicle in terms of seat position and seatbelt use was investigated. In addition, elderly occupants were divided into a younger-old group aged between 65 and 74 years and an older-old group aged 75 years and older in an effort to assess whether the conventional elderly age standard of 65 years should be reconsidered.

METHODS

A multinomial logit framework was adopted to predict two-level injury severity using collision data between 2008 and 2015. Predictor variables included gender, age group, seat position, seatbelt, road type, road slope, road surface, road line, and type of vehicle. Five models, a base model with no interactions and four interaction models which were combinations of age group, seatbelt use and seat position, were devised and evaluated.

RESULTS

With no interacting term, age was the most prominent predictor. Elderly occupants were most likely to suffer from severe injury without a seatbelt in all seat positions, and the use of a seatbelt reduced this likelihood the most in the elderly group as well. Front passenger seats had the highest risk to elderly occupants, while the driver seat was statistically insignificant. When the elderly group was divided into the younger-old group and the older-old group, the older-olds were found to be much more vulnerable compared to the younger-olds. In particular, older drivers were five times more likely to suffer a severe injury without a seatbelt.

CONCLUSIONS

The degree of injury severity of elderly occupants was reduced the most with the use of a seatbelt, demonstrating the importance of using seat restraints. The sharp increase in the risk of injury of the older-old group suggests that the age standard of 65 years as the elderly group with regard to traffic safety may require reconsideration due to the growing number of elderly vehicle users on the road. Our results provide practical evidence with which to formulate new safety policies, including mandatory seatbelt use, driving age limits and insurance pricing.

Teste do bafômetro: resultados e recusas de motoristas interceptados pela Operação Lei Seca no Rio de Janeiro

Resumo Estudo transversal que avaliou os resultados e as recusas ao teste do bafômetro entre motoristas interceptados pela Operação Lei Seca na capital do Rio de Janeiro e Baixada Fluminense. Realizado com base em dados cedidos pelo Governo do Estado que foram coletados durante atendimento de motoristas interceptados entre dezembro de 2013 e janeiro de 2014. Procederam-se análises descritivas da amostra e de associação entre as variáveis sexo, faixa etária e local de abordagem com as recusas e os resultados do teste do bafômetro através de um modelo de regressão logística. Dos 4756 (100%) condutores interceptados, 59 (1,2%) apresentaram resultado positivo no teste do bafômetro e 229 (4,8%) recusaram-no. Apenas a variável local de abordagem apresentou significância estatística com maiores chances de resultados positivos (OR = 4,01) e recusas ao teste (OR = 5,14) entre os condutores interceptados na Baixada Fluminense. As ações sistemáticas de fiscalização efetuadas pela Operação Lei Seca que ocorrem há mais tempo na capital parecem influenciar positivamente o comportamento de beber e dirigir dos motoristas.

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.

The scope and nature of injuries to rear seat passengers in NSW using linked hospital admission and police data

OBJECTIVE

To compare the pattern of injuries to front and rear seat occupants and test the hypothesis that rear seat passengers of different ages sustain different patterns of injury.

METHOD

Patients admitted to a hospital following involvement in a crash in New South Wales (NSW) Australia between 2005 and 2007 were identified using International Classification of Diseases (10th edition [ICD10]) codes. Hospital admissions data were linked with NSW police crash data using probabilistic techniques. The profiles and patterns of injury of front and rear seat passengers were compared. Logistic regression was used to examine how age influenced the pattern of injury among rear seat passengers.

RESULTS

Sixty-three percent of hospital admissions were linked with police records. One in 5 passengers were rear seat passengers. There were more unrestrained occupants in the rear (7%) compared to drivers (3%) and front seat passengers (2%). Younger (9-15 years) injured passengers were seated in the rear more often than in the front passenger position and older injured passengers (>50 years) were seated more often in the front passenger position than in the rear (15% rear compared to 5% front aged 9-15 years; 22% rear compared to 37% front aged >50 years; χ(2), P < .001). There were proportionally more fatal injuries among rear seat passengers (10%) than among drivers (5%) and front seat passengers (6%), and the pattern of injury between front and rear passengers also varied. Rear seat passengers had more head and abdominal injuries and fewer thoracic and knee/lower leg injuries than front seat passengers. After adjusting for vehicle age, restraint status, travel speed, and whether or not a fatality occurred in the crash, older (>50 years) rear passengers had 6.3 times the odds of sustaining thoracic injuries (95% confidence interval [CI], 2.6-15.0) and lower odds (odds ratio [OR] = 0.4, 95% CI, 0.2-0.9) of sustaining abdominal/lumbar injuries than the youngest occupants (9-15 years).The odds of sustaining a head injury did not vary with age, and the odds of sustaining thoracic, abdominal, or lower extremity injuries did not differ significantly between rear seat passengers aged 16-50 years and 9-15 years.

CONCLUSIONS

The findings suggest that there is a need for enhanced protection for rear seat passengers, because they have proportionally more fatal injuries than front-seated occupants. The frequency of abdominal injury and the differences between injury patterns observed in front seat passengers suggests a potential benefit from adding abdominal injury risk assessment to rear seat occupant protection test protocols. There is also scope to improve chest protection for older rear seat passengers.

National and regional analysis of road accidents in Spain

OBJECTIVE

In Spain, the absolute fatality figures decreased almost 50 percent between 1998 and 2009. Despite this great effort, road mortality is still of great concern to political authorities. Further progress requires efficient road safety policy based on an optimal set of measures and targets that consider the initial conditions and characteristics in each region. This study attempts to analyze road accidents in Spain and its provinces in time and space during 1998-2009.

METHODS

First, we analyzed daily, monthly, and nationwide (NUTS 0) development of road accidents, the correlation between logarithmic transformations of road accidents and territorial and socioeconomic variables, the causality by simple linear regression of road accidents and territorial and socioeconomic variables, and preliminary frequency by fast Fourier transform. Then we analyzed the annual trend in accidents in the Spanish provinces (NUTS 3) and found a correlation between the logarithmic transformations of the mortality rate, fatalities per fatal accident, and accidents resulting in injuries per inhabitant variables and population, population density, gross domestic product (GDP), length of road network, and area. Finally, causality was analyzed by simple linear regression.

RESULTS

The most outstanding results were the negative correlation between mortality rate and population density in Spanish provinces, which has increased over time, and that road accidents in Spain have an approximate periodicity of 57 days.

CONCLUSIONS

The fast Fourier transform analysis of road accident frequency in Spain was useful in identifying the periodic, harmonic components of accidents and casualties. The periodicity observed both for the period 1998-2009 and by year showed that the highest intensity in road accidents was bimonthly, despite the lower number of accidents and casualties in the spectra of amplitude and power and efforts to reduce the intensity and concentration during off-season travel (summer and December).

Mortality rate in children caused by traffic accidents according to geographical regions : Brazil, 1997 - 2005

Fatal injuries in children caused by motor vehicle accidents represent a common situation in many countries worldwide. The present study addresses the mortality rate in children as vehicle passengers in Brazil, from 1997 to 2005. To evaluate mortality rates, the number of deaths was collected from the National Mortality Information System (SIM) and the population size was obtained using the Brazilian Bureau Census (IBGE) data available at DATASUS. Mortality rates were estimated in three-year periods and analyzed according to age groups (younger than 1 year old, 1-4 years old, 5-9 years old) and geographical regions using a 95% confidence interval. Overall results showed mortality rates of 5.68, 7.32 and 6.78 (per 1,000,000) for the 1997-1999, 2000-2002 and 2003-2005 periods, respectively for the whole country. Children younger than 1 year old had a mortality rate of 10.18 (per 1,000,000), which was higher than for the other age groups. For the period analyzed, the highest rates were observed for the Mid-West and South regions of Brazil, with rates of 13.88 and 11.47 (per 1,000,000), respectively. These results show the risk of fatal injury in children caused by motor vehicle accidents and may contribute to the establishment of educational campaigns aiming injury prevention in children as vehicle passengers.

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.

An econometric analysis of the effects of the penalty points system driver's license in Spain

This article seeks to quantify the effects of the penalty points system driver's license during the 18-month period following its coming into force. This is achieved by means of univariate and multivariate unobserved component models set up in a state space framework estimated using maximum likelihood. A detailed intervention analysis is carried out in order to test for the effects and their duration of the introduction of the penalty points system driver's license in Spain. Other variables, mainly indicators of the level of economic activity in Spain, are also considered. Among the main effects, we can mention an average reduction of almost 12.6% in the number of deaths in highway accidents. It would take at least 2 years for that effect to disappear. For the rest of the safety indicator variables (vehicle occupants injured in highway accidents and vehicle occupants injured in accidents built-up areas) the effects disappeared 1 year after the law coming into force.

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 effectiveness of child restraint systems for children aged 3 years or younger during motor vehicle collisions: 1996 to 2005

OBJECTIVES

We estimated the effectiveness of child restraints in preventing death during motor vehicle collisions among children 3 years or younger.

METHODS

We conducted a matched cohort study using Fatality Analysis Reporting System data from 1996 to 2005. We estimated death risk ratios using conditional Poisson regression, bootstrapping, multiple imputation, and a sensitivity analysis of misclassification bias. We examined possible effect modification by selected factors.

RESULTS

The estimated death risk ratios comparing child safety seats with no restraint were 0.27 (95% confidence interval [CI] = 0.21, 0.34) for infants, 0.24 (95% CI = 0.19, 0.30) for children aged 1 year, 0.40 (95% CI = 0.32, 0.51) for those aged 2 years, and 0.41 (95% CI = 0.33, 0.52) for those aged 3 years. Estimated safety seat effectiveness was greater during rollover collisions, in rural environments, and in light trucks. We estimated seat belts to be as effective as safety seats in preventing death for children aged 2 and 3 years.

CONCLUSIONS

Child safety seats are highly effective in reducing the risk of death during severe traffic collisions and generally outperform seat belts. Parents should be encouraged to use child safety seats in favor of seat belts.