The effects of health status, distress, alcohol and medicinal drug use on subsequent motor vehicle injuries

OBJECTIVE

The purpose of this study was to examine the effects of health factors and substance use on subsequent motor vehicle collision (MVC) injuries of three different age groups, using the longitudinal dataset from the Canadian National Population Health Survey (NPHS) for the years 1994-2002.

METHODS

Path analysis technique was used to determine the relations between MVC injury and four risk factors: binge drinking; health status; distress; and medication use. The three demographic variables, age at 'baseline', sex, and immigration status were added into the model as control variables. Three age groups were examined: young=12-29.9; middle-aged=30-59.9 and old=60-85 years of age. The total sample size was 16,093.

RESULTS

A lower percentage of males, older persons, immigrants, and non-binge drinkers reported a subsequent MVC injury, as did respondents reporting better health and lower distress scores. Medication use was associated with higher subsequent MVC injuries. Path analysis found that among younger individuals, the variable binge drinking, was the only significant risk factor associated with subsequent injuries. In contrast, among middle-aged individuals, the variable medication use, was the only statistically significant risk factor for subsequent injuries. No variables were significant risk factors of injuries for older individuals.

CONCLUSIONS

Various demographic and risk factors were found to influence injuries among a nationally representative sample of Canadians. Reported binge drinking among young individuals and medication use among middle-aged individuals were found to be risk factors for subsequent MVC injury. These findings support the need for continued focus on alcohol, drugs and traffic safety.

The immediate and long-term impact of physical and/or emotional stress from motor vehicle accidents on circulating stress hormones and adipo-cytokines in children and adolescents

Motor vehicle accidents (MVA) represent a complex physical and emotional stressor. Consequent short- and/or long-term alterations on the circulating concentrations of stress hormones and adipo-cytokines may have potential health implications. Fifty-nine children and adolescents, aged 7-18 years, were evaluated within 24 h after hospitalization for a MVA, and 1 and 6 months later; 40 children served as controls. We examined longitudinally the effects of physical injury-associated (PI) group vs. emotional-only stress (ES) group on circulating cortisol, catecholamine, interleukin (IL)-6, leptin and adiponectin concentrations. Within 24 h after the accident, serum cortisol concentration was greater than the controls in the PI but not the ES group (p = 0.02), while serum IL-6 concentration was greater in both trauma groups than in the controls (p = 0.004 for PI, p = 0.04 for ES). Adiponectin concentration was lower in the PI than the ES (p = 0.031) and the control (p = 0.019) groups and this was mainly attributed to females. The catecholamine and leptin concentrations were similar in the three groups. At the 1 and 6 month evaluations, cortisol and IL-6 concentrations in both trauma groups became normal. Adiponectin concentration in females, however, remained low 1 and 6 months after the accident (p = 0.03 for month six). In conclusion, circulating IL-6 concentration was influenced equally by the physical and emotional stress shortly after the trauma. Physical but not emotional-only stress lowered the circulating adiponectin concentrations in females and this effect persisted for at least 6 months.

Influence of active muscle contribution on the injury response of restrained car occupants

Optimal performance of adaptive restraint systems requires an accurate assessment of occupant parameters including physical properties and pre-collision behavior of the occupant. Muscle bracing, one of the key reflexive actions adopted by car occupants to mitigate the severity of an impending collision, is ignored in restraint designing since conventional human surrogate tools used for injury assessment due to collision loading provide limited insight into this effect. This study is aimed at evaluating the effect of pre-collision muscle bracing on the injury outcome of an occupant using a simplified numerical musculoskeletal model. The activation levels for 12 major muscle groups loading the ankle, knee, hip and elbow joints, were determined using an optimization routine with data collected from previously reported volunteer sled tests. A whole body injury metric, weighted to the severity of injury and the injured body region, was used to evaluate the potential risk of injuries estimated for different levels of bracing. The musculoskeletal model was further used to determine the requirements on the restraint system properties to minimize overall injuries for an occupant in a relaxed and a braced condition. Significant variation was observed in the load-limiting value and pre-tensioner firing time, as the restraint properties were optimized to account for the bracing behavior. The results of the study provide a framework for improving the performance of adaptive restraint systems, currently designed for passive anthropometric tests devices, by taking into account realistic response of the occupant involved in a collision.

Presence of passengers: does it increase or reduce driver's crash potential?

This study examines the impact of passengers on the driver's crash potential on freeways. To estimate the impact, a set of bivariate probit models were developed using the 5-year (1999-2003) crash records on a 36.3-mile stretch of Interstate-4 freeway (I-4) in Orlando, Florida. Bivariate probit models identify the correlation between potentially inter-related choices of three passenger characteristics and three crash characteristics. The analysis using bivariate probit models showed that there exist strong correlations between passenger and crash characteristics. It was found that drivers generally display safer driving behavior when they are accompanied by passengers, and more passengers reduce driver's crash potential. It was also found that younger driver's crash potential increases with the presence of a younger passenger only. In addition, the analysis of crash type using traffic flow parameters at the time of crashes showed that young drivers with only younger passengers are more likely to be involved in single-vehicle crashes in high-speed and low-volume conditions. The findings in this study provide insight into how the presence of passengers has an impact on driver behavior and traffic safety in various conditions.

The role of perceived injustice in the experience of chronic pain and disability: scale development and validation

INTRODUCTION

The primary objective of this research was to evaluate the psychometric properties of a questionnaire designed to assess perceive injustice associated with injury.

METHODS

In Study 1, the 12-item Injustice Experience Questionnaire (IEQ) was administered to 226 individuals with musculoskeletal conditions. A subsample of 85 individuals were interviewed 1-year later about their ongoing symptoms and return to work status. In Study 2, the IEQ and other pain-related measures were administered on two separate occasions to 70 pain patients participating in a functional restoration rehabilitation program.

RESULTS

-Study 1 Principal components analysis yielded a two-component solution with eigenvalues greater 1. Item content of the two components reflected elements of blame and irreparability of loss. In cross sectional analyses, the IEQ was significantly correlated with measures of catastrophic thinking, r = .75, P < .01, fear of movement/re-injury, r = .58, P < .01, depression, r = .66, P < .01, and pain severity, r = .54, P < .01. Cross-sectional regression analyses revealed that the IEQ, beta = .44, P < .01, and the PCS, beta = .18, P < .05, each contributed significant unique variance to the prediction of pain severity. The IEQ prospectively predicted return to work status, OR = .75, 95% CI = .58-.99, but not pain severity.

RESULTS

-Study 2 Analyses supported the test re-test reliability of the IEQ, r = .90, P < .01. Treatment-related changes in the IEQ were significantly correlated with an objective index of improved physical function, r = .51, P < .01.

CONCLUSIONS

The findings of these two studies support the construct validity of the IEQ and suggest that this measure might be a useful complement to psychosocial assessment of individuals with persistent pain conditions. Discussion addresses the processes through which perceived injustice might impact on disability and rehabilitation outcomes.

Relationships between interest in motor racing and driver attitudes and behaviour amongst mature drivers: an Australian case study

Interest in motor racing is investigated as a possible source of influence on driver attitudes toward speeding and driver behaviour. Previous studies have identified links between motor racing and road accidents on public roads. One study found that the level of interest in motor racing was positively correlated with risky driving behaviours of young male drivers. This paper outlines a conceptual framework for investigating the association between interest in motor racing and speeding violations on public roads. A sample survey of households in Queanbeyan, NSW, was used to examine the relationship between the level of interest in motor racing and attitudes to speeding and driving violations in a group of mature drivers. Results indicate that the level of interest in motor racing is significantly related to attitudes towards speeding, controlling for age, education level and sensation seeking propensity. Higher levels of interest in motor racing are associated with higher pro-speeding attitudes. Unlike the previous research on young male drivers, there was no significant relationship between interest in motor racing and speeding violations for this study of mature drivers. The implications of the study for road safety interventions are discussed.

Evolution of road risk disparities at small-scale level: example of Belgium

PROBLEM

Road accident outcomes are traditionally analyzed at state or road network level due to a lack of aggregated data and suitable analytical methods. The aim of this paper is to demonstrate usefulness of a simple spatiotemporal modeling of road accident outcomes at small-scale geographical level.

METHOD

Small-area spatiotemporal Bayesian models commonly used in epidemiological studies reveal the existence of spatial correlation in accident data and provide a mechanism to quantify its effect. The models were run for Belgium data for the period 2000-2005. Two different scale levels and two different exposure variables were considered under Bayesian hierarchical models of annual accident and fatal injury counts. The use of the conditional autoregressive (CAR) formulation of area specific relative risk and trend terms leads to more distinctive patterns of risk and its evolution. The Pearson correlation tests for relative risk rates and temporal trends allows researchers to determine the development of risk disparities in time.

RESULTS

Analysis of spatial effects allowed the identification of clusters with similar risk outcomes pointing toward spatial structure in road accident outcomes and their background mechanisms. From the analysis of temporal trends, different developments in road accident and fatality rates in the three federated regions of Belgium came into light. Increasing spatial disparities in terms of fatal injury risk and decreasing spatial disparities in terms of accident risk with time were further identified.

IMPACT ON INDUSTRY

The application of a space-time model to accident and fatal injury counts at a small-scale level in Belgium allowed identification of several areas with outstandingly high accident (injury) records. This could allow more efficient redistribution of resources and more efficient road safety management in Belgium.

Clinical and sociodemographic variables associated with the onset of posttraumatic stress disorder in road traffic accidents

Our objective was to identify variables related to the onset of acute posttraumatic stress disorder (PTSD) after a road traffic accident. We evaluated 60 victims of a motor vehicle accident (MVA) in 2004 at 2 months postaccident. Thirty of them had developed PTSD; the other 30 had not developed PTSD. Clinical data, physical injuries, and sociodemographic characteristics were determined in 60 victims. The Davidson Trauma Scale (DTS) and a Structured Clinical Interview for DSM-IV (SCID) were used to evaluate PTSD occurrence. PTSD scores assessed by DTS and SCID at 2 months were significantly and positively associated with female sex, severe physical injuries, perceived social deprivation, and loss of job activity due to the accident. Female sex, severe physical injury, perceived social deprivation, and sick leave were related to the diagnosis of PTSD 2 months after the accident.

The relationship between self-regulation and driving-related abilities in older drivers: an exploratory study

OBJECTIVES

The objectives of this paper are to review the published research findings about the role of self-regulation in older driver safety and to report on an exploratory study to better understand the self-regulatory practices of older drivers as demonstrated through the avoidance of a number of specific driving situations including making left turns and driving alone, at night, in bad weather, in high traffic, and on the expressway and through restricting driving to familiar or local areas only.

METHODS

As part of a larger study on the development and testing of a self-screening instrument by older drivers, data on self-regulation were compared with data on driving-related abilities collected through clinical and on-road assessments for 68 drivers age 65 and older.

RESULTS

Findings indicate that 25% of subjects reported self-regulating their driving in some way. Of those who self-regulated, five individuals reported avoiding just one type of driving situation, six reported avoiding two, one reported avoiding three, and five reported avoiding four types of situations. The most frequently reported situations were avoiding driving at night (19.1%) in bad weather (8.8%), and driving only in local areas (13.2%). Women were considerably more likely than men to report self-regulatory practices. Consistent with the findings of low avoidance of driving situations, subjects generally reported high levels of confidence, with the exception of driving at night, for which over one third of women reported being "not at all confident." Overall, subjects were least confident driving at night, in bad weather, and on express ways. Results from a logistic regression model indicate that subjects did appear to self-regulate their driving at night based on their performance on the on-road driving assessment (p < .01). That is, for every 10-unit decrease in driving score (with lower scores indicating poorer driving performance), subjects were 1.6 times more likely to self-regulate.

CONCLUSIONS

Continuing research on the extent to which older drivers appropriately self-regulate their driving is warranted. Future studies should focus on objectively measuring self-regulation, possibly through instrumented vehicle studies, and comparing these measures with clinically determined functional abilities and driving performance. It is also important to take into account differences in self-regulation by sex, as well as the effects of confidence in driving ability and insight into functional impairments on self-regulation.

Perceived risk, resources, and perceptions concerning driving and epilepsy: a patient perspective

Previous research on driving and epilepsy has focused primarily on determining predictors of who will continue to drive when told not to. An analysis of health behavior attitudes and beliefs in persons with epilepsy may provide insight into effective patient counseling. A three-page, 46-item questionnaire was adapted and completed by 213 respondents with epilepsy. Nineteen percent indicated that in order to drive, they were not completely honest about their seizure frequency. Twenty-six percent reported having had a car accident because of a seizure. On Safety Concern, Attitudes toward Driving, Perceived Severity/Susceptibility, Perceived Barriers, Helping Relationships, and Self-Efficacy, there were no significant differences with respect to gender or place of residence. Respondents indicated that being in good health and taking precautions were important to them. Predictors of driving behavior included race/ethnicity, employment status, dishonesty about seizure frequency with the doctor, Attitudes toward Driving, Perceived Severity/Susceptibility, Perceived Barriers to changing driving behavior, and Self-Efficacy. Recommendations for communication strategies are discussed.

A logistic model of the effects of roadway, environmental, vehicle, crash and driver characteristics on hit-and-run crashes

Leaving the scene of a crash without reporting it is an offence in most countries and many studies have been devoted to improving ways to identify hit-and-run vehicles and the drivers involved. However, relatively few studies have been conducted on identifying factors that contribute to the decision to run after the crash. This study identifies the factors that are associated with the likelihood of hit-and-run crashes including driver characteristics, vehicle types, crash characteristics, roadway features and environmental characteristics. Using a logistic regression model to delineate hit-and-run crashes from nonhit-and-run crashes, this study found that drivers were more likely to run when crashes occurred at night, on a bridge and flyover, bend, straight road and near shop houses; involved two vehicles, two-wheel vehicles and vehicles from neighboring countries; and when the driver was a male, minority, and aged between 45 and 69. On the other hand, collisions involving right turn and U-turn maneuvers, and occurring on undivided roads were less likely to be hit-and-run crashes.

Traumatic events and depressive symptoms among youth in Southwest Nigeria: a qualitative analysis

Traumatic experiences have dire consequences for the mental health of young persons. Despite high rates of traumatic experiences in some African cities, there are no reports for Nigerian youth.

OBJECTIVE

To investigate the pattern of traumatic events and their association with depressive symptoms among youth in Southwest Nigeria.

METHODS

This is a descriptive cross-sectional study of randomly selected youth in urban and rural schools in Southwest Nigeria. They completed self-reports on traumatic events and depressive symptoms using the Street Children's Project Questionnaire and the Youth DISC Predictive Scale (DPS).

RESULTS

Of the 1,768 responses (88.4% response rate) entered into the analysis, 34% reported experiencing a traumatic situation. Following interpretative phenomenological analysis, 13 themes emerged. Frequently occurring traumatic events were 'road traffic accidents' (33.0%), 'sickness' (17.1%), 'lost or trapped' (11.2%) and 'armed robbery attack' (9.7%). A bad dream was described by 3.7%. Traumatic experiences were commoner in males (36.2%) than in females (31.6%) (x2 = 4.2; p = .041). Experiencing a traumatic event was associated with depressive symptoms (X2 = 37.98; p < .001), especially when the event directly affected the youth as in sexual assault or physical abuse.

CONCLUSIONS

One-third of youth in Southwest Nigeria have described an experienced traumatic event. Road traffic accidents, armed robbery attacks, and communal disturbances depict the prevailing social environment, whereas 'bad dreams' revealed the influence of cultural beliefs. Policy makers must be aware of the social issues making an impact on the health of youth. Multi-agency interventions to improve the social environment and provide mental health services for traumatized young people are essential.

Personality factors as predictors of persistent risky driving behavior and crash involvement among young adults

OBJECTIVES

The aim of this study was to examine the relationship between personality factors assessed during adolescence and persistent risky driving behavior and traffic crash involvement among young adults.

DESIGN

Data for this investigation were drawn from the Dunedin Multidisciplinary Health and Development Study, a longitudinal study of a cohort born in Dunedin, New Zealand.

SUBJECTS

The study population was 1037 young people born between 1 April 1972 and 31 March 1973.

MAIN OUTCOME MEASURES

The main outcome measures were persistent risky driving behaviors and crash involvement, collected in a face-to-face road-safety interview at ages 21 and 26.

RESULTS

The only outcomes for which there were sufficient numbers of females were a driver involved in any crash and a driver involved in an injury crash. Univariate logistic regression revealed that there were no significant predictors for either of these outcomes. For the males, at the univariate level, aggression, traditionalism, and alienation were the personality scales most frequently associated with risky driving behavior and crash risk. After adjusting for driving exposure, only high levels of aggression predicted being a driver involved in a crash, and alienation predicted being a driver involved in an injury crash.

CONCLUSION

These results suggest that road-safety interventions seeking to deter young adult males from persistent risky driving behavior need to be directed at those who do not endorse traditional views, are aggressive, and feel alienated from the rest of society.

Brief motivational intervention to increase self-reported safety belt use among emergency department patients

OBJECTIVES

Brief motivational interventions have shown promise in reducing harmful behaviors. The authors tested an intervention to increase safety belt use (SBU) among emergency department (ED) patients.

METHODS

From February 2006 to May 2006, the authors conducted a randomized trial of adult ED patients at a teaching hospital in Boston. ED patients were systematically sampled for self-reported SBU. Those with SBU other than "always" were asked to participate. At baseline, participants answered a 9-item series of situational SBU questions, each scored on a 5-point Likert scale. SBU was defined as a continuous variable (9-item average) and as a dichotomous variable (response of "always" across all items). Participants were randomized to an intervention or a control group. The intervention group received a 5- to 7-minute intervention, adapted from classic motivational interviewing techniques, by a trained interventionist. Participants completed a 3-month follow-up phone survey to determine changes from baseline SBU. Continuous and dichotomous SBU were analyzed via analysis of covariance and chi-square testing.

RESULTS

Of 432 eligible patients, 292 enrolled (mean age 35 years, standard deviation [SD] +/-11 years; 61% male). At baseline, the intervention and control groups had similar mean (+/-SD) SBU scores (2.8 [+/-1.1] vs. 2.6 [+/-1.1], p = 0.31) and SBU prevalence (each 0%). At 3 months, 81% completed follow-up. The intervention group had significantly greater improvement in mean (+/-SD) SBU scores than controls (0.76 [+/-0.91] vs. 0.34 [+/-0.88], p < 0.001). Also, SBU prevalence of "always" was higher for the intervention group than controls (14.4% vs. 5.9%, p = 0.03).

CONCLUSIONS

Participants receiving a brief motivational intervention reported higher SBU at follow-up compared to controls. An ED-based intervention may be useful to increase SBU.

Limits of the quasi-induced exposure method when compared with the standard case-control design. Application to the estimation of risks associated with driving under the influence of cannabis or alcohol

The disparities between the quasi-induced exposure (QIE) method and a standard case-control approach with crash responsibility as disease of interest are studied. The 10,748 drivers who had been given compulsory cannabis and alcohol tests subsequent to involvement in a fatal crash in France between 2001 and 2003 were used to compare the two approaches. Odds ratios were assessed using conditional and unconditional logistic regressions. While both approaches found that drivers under the influence of alcohol or cannabis increased the risk of causing a fatal crash, the two approaches are not equivalent. They differ mainly with regards to the driver sample selected. The QIE method results in splitting the overall road safety issue into two sub-studies: a matched case-control study dealing with two-vehicle crashes and a case-control study dealing with single-vehicle crashes but with a specific control group. Using a specific generic term such as "QIE method" should not hide the real underlying epidemiological design. On the contrary, the standard case-control approach studies drivers involved in all type of crashes whatever the distribution of the responsibility in each crash. This method also known as "responsibility analysis" is the most relevant for assessing the overall road safety implications of a driver characteristic.

Cyclists' perception of risk in roundabouts

Converting an intersection into a roundabout improves motor vehicle safety, but a similar safety effect is not found for car-bicycle collisions. Very little is known about the reasons behind these collisions. In this study a first step towards an understanding of the reasons behind these collisions is taken. The study focuses on cyclists' perceived risk in specific situations, factors influencing the perception of risk and cyclists' knowledge about traffic rules regulating the interaction between road users in roundabouts. One thousand and nineteen cyclists aged 18-85 participated in the study. Data were collected using structured interviews conducted in five Danish roundabouts. Underestimation of risk and lack of knowledge about relevant traffic rules may contribute to car-bicycle collisions in roundabouts. Cyclists prefer road designs with a clear regulation of road user behaviour. A need to increase knowledge about traffic rules regulating road user behaviour in roundabouts is identified.

Cognitive failures as predictors of driving errors, lapses, and violations

Dual-process models from the cognitive literature have proposed a taxonomy of cognitive failures in everyday activities, and this novel approach was applied to understanding driver behaviour. This framework was used to examine whether categories of cognitive failure would explain driving errors, driving lapses, and driving violations in a sample of undergraduates at a large urban university. Two types of cognitive failure were examined, one associated with missing affective information and the other associated with a failure to engage effortful processes to override an automatic response. Alexithymia was used as an indicator of missing affective information, and attention regulation, reactivity, and impulsivity were used as indicators of override failure. Relevant demographic variables included gender and hours typically driven. Override failures were significantly associated with driving behaviour in the correlational analyses. In the regression analyses, attention regulation predicted driving errors, and gender, attention regulation, and impulsivity predicted driving violations. The implications of this work include the potential application to driver training, to users of informatics devices (e.g., GPS, cellular phones, messaging systems), and for individuals diagnosed with attention and/or impulsivity problems.

Car drivers' attitudes towards motorcyclists: a survey

Motorcyclists are over-represented in UK traffic accident statistics. Many car-motorcycle accidents are however due to the inappropriate actions of car drivers. It is predicted that car drivers at risk of collision with motorcycles have divergent attitudes and beliefs about motorcyclists compared to safer drivers, which may lead to a deficient mental model guiding their interactions with motorcyclists. To assess car drivers' attitudes towards motorcyclists, a survey was undertaken. Respondents filled in 26 general and motorcycle-related items and the 24 items of the reduced Driver Behaviour Questionnaire. Compared to an experienced dual driver group (who both drive cars and ride motorcycles), all other drivers showed divergent beliefs and attitudes. Four factors were extracted from the motorcycle items: negative attitudes, empathic attitudes, awareness of perceptual problems, and spatial understanding. Car drivers with a moderate amount of experience (between 2 and 10 years driving) held the most negative views and reported the most violations. The results have lead to several suggestions for interventions aimed at decreasing the divergence between drivers' perceptions of motorcyclists, and the perceptions of experienced dual drivers.

The experiences and perceptions of heavy vehicle drivers and train drivers of dangers at railway level crossings

Heavy vehicle-train collisions have the potential to be catastrophic in terms of fatalities, environmental disaster, delays in the rail network, and extensive damage to property. Heavy vehicles, such as 'Road Trains' and 'B-Doubles', are vulnerable road users due to their size and mass and require specific risk management solutions. The present study aimed to capture the experiences of heavy vehicle drivers and train drivers at road-rail level crossings, with a view to exploring the contributing factors toward such accidents. A series of semi-structured focus groups was conducted, with a total of 17 train drivers and 26 heavy vehicle drivers taking part. Though there were some differences between the groups in perceptions of the causes of heavy vehicle-level crossing incidents, discussion in both groups centred on design issues an behavioural issues. With regard to design, the configuration of level crossings was found to affect heavy vehicle driver visibility and effective vehicle clearance. With regard to behaviour, discussion centred around wilful violation of crossing protocols, often as a time-saving measure, as well as driver complacency due to high levels of familiarity. The implications of these factors for future level crossing safety initiatives are discussed.

Driver irritation and aggressive behaviour

A sample of 98 drivers responded to a Swedish version of the UK Driving Anger Scale [UK DAS; [Lajunen, T., Parker, D., Stradling, S.G., 1998. Dimensions of driver anger, aggressive and highway code violations and their mediation by safety orientation in UK drivers. Transport. Res. Part F 1, 107-121]. The results indicated that the Swedish version, like the British original, measures three sources of driver irritation: "progress impeded", "reckless driving", and "direct hostility". Structural equation modelling was used to investigate the relationships between the three sources of self-reported driver irritation, aggressive actions, speed, sex, age, and annual mileage. The models suggested a positive relationship between the amount of driver irritation and frequency of aggressive actions for all three sources of irritation. Female drivers tended to become more irritated than male drivers, while the male drivers tended to act aggressively more often. Surprisingly, drivers who reported that they enjoy fast speeds did not become more irritated than slower drivers when obstructed. The important conclusions are that experienced irritation often leads to openly aggressively actions, and that expression of aggressive behaviours may be a cause of other drivers' feeling of irritation.

The impact of social support: an analogue investigation of the aftermath of trauma exposure

Recent meta-analytic studies suggest that social support plays an important role in regulating the severity of post-traumatic adjustment; however, few studies have manipulated potential underlying mechanisms. This analogue study examined how various social reactions, following trauma exposure, influenced subsequent anxiety, affect, and intrusive thoughts. Ninety-three participants viewed a distressing videotape followed by a portrayal of positive, negative, or neutral social reactions. While negative reactions increased initial negative affect, neutral reactions increased later frequency and severity of intrusive thoughts. Based on this, it was suggested that "neutral" social reactions following trauma exposure may have the potential for being highly invalidating and in some circumstances may actually have more negative later effects than overtly negative ones.

Do cognitive models help in predicting the severity of posttraumatic stress disorder, phobia, and depression after motor vehicle accidents? A prospective longitudinal study

The study investigated the power of theoretically derived cognitive variables to predict posttraumatic stress disorder (PTSD), travel phobia, and depression following injury in a motor vehicle accident (MVA). MVA survivors (N = 147) were assessed at the emergency department on the day of their accident and 2 weeks, 1 month, 3 months, and 6 months later. Diagnoses were established with the Structured Clinical Interview for DSM-IV. Predictors included initial symptom severities; variables established as predictors of PTSD in E. J. Ozer, S. R. Best, T. L. Lipsey, and D. S. Weiss's (2003) meta-analysis; and variables derived from cognitive models of PTSD, phobia, and depression. Results of nonparametric multiple regression analyses showed that the cognitive variables predicted subsequent PTSD and depression severities over and above what could be predicted from initial symptom levels. They also showed greater predictive power than the established predictors, although the latter showed similar effect sizes as in the meta-analysis. In addition, the predictors derived from cognitive models of PTSD and depression were disorder-specific. The results support the role of cognitive factors in the maintenance of emotional disorders following trauma.

Coping self-efficacy mediates the effects of negative cognitions on posttraumatic distress

Although cognitive distortions have predicted posttraumatic distress after various types of traumatic events, the mechanisms through which cognitive distortions influence posttraumatic distress remain unclear. We hypothesized that coping self-efficacy, the belief in one's own ability to manage posttraumatic recovery demands, would operate as a mediator between negative cognitions (about self, about the world, and self-blame beliefs) and posttraumatic distress. In the cross-sectional Study 1, data collected among 66 adult female victims of child sexual abuse indicated that coping self-efficacy mediated the effects of negative cognitions about self and about the world on posttraumatic distress. The same pattern of results was found in a longitudinal Study 2, conducted among 70 survivors of motor vehicle accidents. Coping self-efficacy measured at 1 month after the trauma mediated the effects of 7-day negative cognitions about self and about the world on 3-month posttraumatic distress. In both studies self-blame was not related to posttraumatic distress and the effect of self-blame on posttraumatic distress was not mediated by coping self-efficacy. The results provide insight into a mechanism through which negative cognitions may affect posttraumatic distress and highlight the potential importance of interventions aimed at enhancing coping self-efficacy beliefs.

Lane change behavior with a side blind zone alert system

This in-traffic study explored the effect of a side blind zone alert (SBZA) system on driver lane change behavior. Such a system may help drivers avoid lane change crashes by warning them with a side mirror display when a vehicle is detected in their blind zone. Participants drove with and without the SBZA system enabled, and were instructed to evaluate vehicle ride characteristics and only given an "incidental" system explanation. Overall, drivers failed to execute "over the shoulder" (blind zone) glances for 68 and 85% of the left and right lane changes, respectively. This suggests that the SBZA display provides information to the driver that often fails to be obtained via over the shoulder glances. In addition, when the SBZA system was enabled there was a 31% reduction in left lane changes attempted without the driver checking the left mirror, and a 23% reduction in right lane changes attempted without the driver checking the inside mirror. These results, coupled with the assumption that "did not see other vehicle" is a principal causal factor in many lane change crashes, suggests that the SBZA system may assist drivers in avoiding lane change crashes.