Acute effects of alcohol on inhibitory control and simulated driving in DUI offenders

Effectiveness of road safety interventions: An evidence and gap map

Background

Road Traffic injuries (RTI) are among the top ten leading causes of death in the world resulting in 1.35 million deaths every year, about 93% of which occur in low- and middle-income countries (LMICs). Despite several global resolutions to reduce traffic injuries, they have continued to grow in many countries. Many high-income countries have successfully reduced RTI by using a public health approach and implementing evidence-based interventions. As many LMICs develop their highway infrastructure, adopting a similar scientific approach towards road safety is crucial. The evidence also needs to be evaluated to assess external validity because measures that have worked in high-income countries may not translate equally well to other contexts. An evidence gap map for RTI is the first step towards understanding what evidence is available, from where, and the key gaps in knowledge.

Objectives

The objective of this evidence gap map (EGM) is to identify existing evidence from all effectiveness studies and systematic reviews related to road safety interventions. In addition, the EGM identifies gaps in evidence where new primary studies and systematic reviews could add value. This will help direct future research and discussions based on systematic evidence towards the approaches and interventions which are most effective in the road safety sector. This could enable the generation of evidence for informing policy at global, regional or national levels.

Search Methods

The EGM includes systematic reviews and impact evaluations assessing the effect of interventions for RTI reported in academic databases, organization websites, and grey literature sources. The studies were searched up to December 2019.

Selection Criteria

The interventions were divided into five broad categories: (a) human factors (e.g., enforcement or road user education), (b) road design, infrastructure and traffic control, (c) legal and institutional framework, (d) post-crash pre-hospital care, and (e) vehicle factors (except car design for occupant protection) and protective devices. Included studies reported two primary outcomes: fatal crashes and non-fatal injury crashes; and four intermediate outcomes: change in use of seat belts, change in use of helmets, change in speed, and change in alcohol/drug use. Studies were excluded if they did not report injury or fatality as one of the outcomes.

Data Collection and Analysis

The EGM is presented in the form of a matrix with two primary dimensions: interventions (rows) and outcomes (columns). Additional dimensions are country income groups, region, quality level for systematic reviews, type of study design used (e.g., case-control), type of road user studied (e.g., pedestrian, cyclists), age groups, and road type. The EGM is available online where the matrix of interventions and outcomes can be filtered by one or more dimensions. The webpage includes a bibliography of the selected studies and titles and abstracts available for preview. Quality appraisal for systematic reviews was conducted using a critical appraisal tool for systematic reviews, AMSTAR 2.

Main Results

The EGM identified 1859 studies of which 322 were systematic reviews, 7 were protocol studies and 1530 were impact evaluations. Some studies included more than one intervention, outcome, study method, or study region. The studies were distributed among intervention categories as: human factors (n = 771), road design, infrastructure and traffic control (n = 661), legal and institutional framework (n = 424), post-crash pre-hospital care (n = 118) and vehicle factors and protective devices (n = 111). Fatal crashes as outcomes were reported in 1414 records and non-fatal injury crashes in 1252 records. Among the four intermediate outcomes, speed was most commonly reported (n = 298) followed by alcohol (n = 206), use of seatbelts (n = 167), and use of helmets (n = 66). Ninety-six percent of the studies were reported from high-income countries (HIC), 4.5% from upper-middle-income countries, and only 1.4% from lower-middle and low-income countries. There were 25 systematic reviews of high quality, 4 of moderate quality, and 293 of low quality.

Authors' Conclusions

The EGM shows that the distribution of available road safety evidence is skewed across the world. A vast majority of the literature is from HICs. In contrast, only a small fraction of the literature reports on the many LMICs that are fast expanding their road infrastructure, experiencing rapid changes in traffic patterns, and witnessing growth in road injuries. This bias in literature explains why many interventions that are of high importance in the context of LMICs remain poorly studied. Besides, many interventions that have been tested only in HICs may not work equally effectively in LMICs. Another important finding was that a large majority of systematic reviews are of low quality. The scarcity of evidence on many important interventions and lack of good quality evidence-synthesis have significant implications for future road safety research and practice in LMICs. The EGM presented here will help identify priority areas for researchers, while directing practitioners and policy makers towards proven interventions.

Meta-analysis of acute alcohol effects on response inhibition

Alcohol intoxication impairs response inhibition; however, discrepant findings have been reported regarding the magnitude and moderators of this effect. This meta-analysis of human laboratory studies aimed to quantify acute effects of alcohol on response inhibition and evaluate moderators of this effect. Eligible studies examined alcohol's effects on response inhibition with the Go/No-Go (GNG) task (n = 1616 participants) or Stop Signal Task (SST) (n = 1310 participants). Results revealed a detrimental effect of acute alcohol on response inhibition overall (g = 0.411, 95 % CI [0.350, 0.471]), with similar effects in studies using GNG (g = 0.431, SE = 0.031) and SST (g = 0.366, SE = 0.063). Effect sizes were larger in studies involving higher breath alcohol concentration levels and under GNG conditions that established a prepotent response set. These findings establish the magnitude, precision, and potential moderators of alcohol's effects on inhibitory control, furthering understanding of a key neurobehavioral mechanism proposed to underlie alcohol-related impulsivity and impaired control over consumption.

A driving simulation study on the effects of different wine types on the performance of young drivers

BACKGROUND

Alcohol consumption is responsible for a significant number of road fatalities. To contrast this phenomenon, a more responsible attitude to the wine consumption, especially among young, inexperienced drivers prone to risky behaviour on the road must be promoted.

METHOD

This is a simplified single-blind, placebo-controlled experiment aimed at evaluating 44 young drivers monitored during a driving simulation following the consumption of natural and conventional wines, with a reference blood alcohol concentration (BAC) of 0.5 g/l. Two hypotheses are tested: (1) the legal consumption of wine has no significant impact on young drivers' performance in both ordinary and unusual road events; (2) natural and conventional wines are expected to produce negligible and acceptable impairments in young drivers the same BAC. Two reference groups (BAC = 0 g/l), one a placebo-controlled group with drivers treated with a dealcoholized wine, were included.

RESULTS AND CONCLUSIONS

Significant differences between the groups in terms of perception and reaction times (PRT) to visual and auditory stimuli, and to speeding were observed, with young drivers treated with conventional wine displaying more aggressive behaviours. In contrast, participants treated with natural wine showed PRT which were not significantly different from those belonging to control groups. The gaze attention levels of wine treated drivers were found to be dose dependant, with young drivers of the two control groups and those of the treated ones with BAC < 0.3 g/l able to focus on wider area ahead and, thereby, collect more information from the road environment.

DUI offenders display reduced perception of intoxication and heightened impulsive choice in response to alcohol

Driving under the influence (DUI) of alcohol continues to be a major contributor in traffic fatalities. There is growing evidence for heightened trait impulsivity in DUI offenders, but little is known about how impulsivity could interact with alcohol intoxication in a manner that would increase the likelihood of driving while intoxicated. This placebo-controlled study examined the acute effects of 0.65g/kg alcohol on 2 facets of impulsivity (impulsive choice and response inhibition), simulated risky driving behavior, and subjective intoxication in a group of 20 DUI offenders and 20 control drivers with no history of DUI. It was predicted that compared with controls, DUI offenders would self-report greater impulsivity, and display greater impulsive choice and driver risk taking, particularly in response to alcohol. Results showed that alcohol impaired drivers' inhibitory control and increased their impulsive choice behavior and risky driving behavior. Alcohol selectively increased impulsive choice of DUI offenders, as control drivers showed no alcohol-induced increase in their impulsive choices. Results also showed that, compared with controls, offenders reported feeling less intoxicated and were more willing to drive after drinking. Laboratory studies are beginning to show that DUI offenders differ from nonoffenders in their acute responses to alcohol. This study identified two alcohol response characteristics of DUI offenders that indicate their lack of risk awareness during intoxication: heightened impulsivity and reduced subjective intoxication. Strategies and treatments to alter these response characteristics in DUI offenders could enhance their risk awareness during the intoxicated state and possibly reduce risk of DUI recidivism. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The effects of alcohol dose, exposure to an in-vehicle alcohol feedback device, and subjective responses to alcohol on the decision to drink-drive in young drivers

BACKGROUND

Several factors may influence the decision to drink-drive (DD) in young drivers, such as the amount of alcohol consumed, exposure to an in-vehicle alcohol feedback device, and subjective responses to alcohol. Understanding of their influence on DD is lacking and may be key for targeted intervention. This randomized controlled, double-blinded, driving simulation experiment tested three main hypotheses; young drivers are more likely to engage in DD with: i) lower alcohol dose; ii) lack of exposure to an in-vehicle alcohol feedback (FB) device; and iii) lower subjective responses to alcohol intoxication (SR). Interactions between the decision to DD and SR, FB and sex were also explored.

METHODS

Males (n = 80) and females (n = 80) aged 20-24 years old were randomly assigned to two conditions: i) alcohol dose (0.45 g/kg or 0.65 g/kg); and ii) exposure to an in-vehicle alcohol feedback device (no or yes). Assessment of participants' SR following alcohol intake was based upon two measures: i) subjective intoxication measured by the discrepancy between an objective measure of intoxication and their subjective estimate of intoxication; and ii) perception of capacity to drive safely under alcohol (for both variables, a higher score represents lower SR). Participants were then asked to make either a negative or positive decision to DD while confronted with time-based contingencies related to their decision. Logistic regression and moderation analyses tested hypotheses.

RESULTS

Approximately 60 % of participants decided to DD. Higher odds of DD were found in participants reporting higher capacity to drive (adjusted odds ratio [β] = 1.03, 95 % confidence interval [CI] = 1.01-1.05) and who were males (β  = 7.70; 95 % CI = 1.34-5.57). A main effect of either FB exposure or alcohol dose was not detected. Moderation analysis showed that lower SR, represented by higher perceived capacity to drive safely under alcohol was selectively predictive of greater likelihood of a decision to DD in participants not exposed to FB (effect = .054, p < .001, 95 % CI = .026-.083).

CONCLUSIONS

Lower SR was found to be associated with a greater likelihood of the decision to DD in young drivers, while exposure to an in-vehicle FB device had no effect on DD. Importantly, FB exposure appeared to disrupt the relationship between lower SR and the decision to DD, signaling that FB may be selectively effective for young drivers possessing lower SR. Future studies are needed to clarify whether FB technology, and other interventions, can be targeted to deter DD in the young drivers most likely to benefit.

Development and validation of a model to predict blood alcohol concentrations: Updating the NHTSA equation

OBJECTS

To date, multiple models have been developed to estimate blood or breath alcohol concentration (BAC/BrAC). Several factors have been identified that affect the discrepancy between BACs/BrACs and retrospective estimation (eBAC) with existing equations. To the best of our knowledge, a model to quantify the effects of factors on the discrepancy between BAC/BrAC and eBAC is still nonexistent. The goal of this work was to develop a model to provide a more accurate retrospective estimation of breath alcohol concentration (eBAC).

METHOD

A laboratory study with alcohol consumption and a driving task was conducted with 30 participants (17 male and 13 female) to explore the factors that may contribute to the discrepancy between BrAC and eBAC obtained with existing models. A new eBAC model was developed to improve the estimation of BrAC by modeling effects of gender, weight, and the delay of BrAC measurement on the discrepancy. The validity of the model was tested and established with the data from the experiment conducted in this study and two published research studies, and compared with existing eBAC models.

RESULTS

Results of the model validity examination indicated that the developed model had higher R squares and lower root-mean-squared errors (RMSE) in estimating BrAC in three experiments compared with the existing eBAC models, including the NHTSA equation, the Matthew equation, the Lewis equation, the Watson equation, and the Forrest equation.

CONCLUSION

The developed eBAC model had a better performance of BrAC estimation compared with existing eBAC models. The validation of the model with the data from three empirical studies indicated a high level of generalizability in estimating BrAC.

Effects of acute alcohol intoxication on executive functions controlling self-regulated behavior

Alcohol consumption may lead to deficits in the executive functions that govern self-regulation. These deficits could lead to risk-taking behaviors; therefore, it is important to determine the magnitude of these deficits on executive functioning. The purpose of this experiment was to investigate the acute effects of alcohol on three of the executive functions that are hypothesized to affect self-regulation, which are inhibition, set shifting, and working memory, using a mixed-methods study design. The participants were 75 moderate or heavy drinkers between the ages of 21 and 35 who were randomized into one of three beverage conditions (control, placebo, or 0.65-g alcohol dose/kg body weight). Performance on working memory, set shifting, and inhibition were measured pre- and post-beverage consumption. The results showed only a significant interaction in the working memory data, as there was an increase in performance post-beverage relative to pre-beverage for the control participants as compared to the alcohol and placebo participants. It was concluded that the dose of alcohol (BAC = 0.063%) given to moderate to heavy drinkers was not sufficient to cause significant impairment in the executive functions tested. The results were further discussed and methodological concerns were considered, such as the low BAC achieved, practice effects, and insensitivity of tasks.

Curbing the DUI offender's self-efficacy to drink and drive: A laboratory study

BACKGROUND

People arrested for driving under the influence of alcohol (DUI) are at high risk to reoffend. One reason for this high rate of recidivism among DUI offenders is that these individuals systematically underestimate the degree to which alcohol impairs their ability to drive. This study compared perceived and objective driving ability following alcohol and performance feedback in drivers with and without a history of DUI.

METHOD

Adult drivers with (n=20) and without (n=20) a history of DUI arrest attended two dose challenge sessions where they received 0.64g/kg alcohol or placebo, completed a simulated driving task, and provided measures of subjective impairment. They attended a third retesting session where they received feedback that they were impaired by alcohol. They received 0.64g/kg alcohol and their objective and perceived driving ability was retested.

RESULTS

Both groups showed significant impairment of driving performance following 0.64g/kg alcohol compared to placebo. DUI offenders rated themselves as less impaired than controls. After performance feedback, self-reported impairment during the alcohol retest increased for DUI offenders but not for controls. There was no effect of performance feedback on objective driving ability.

CONCLUSIONS

These results support the notion that under alcohol DUI offenders characteristically perceive themselves as better able to drive than non-offenders. These perceptions can be tempered by performance feedback. To the extent that perceived ability to drive safely after drinking contributes to DUI and its recidivism, feedback geared towards lowering this self-efficacy could reduce willingness to engage in this behavior.

Support Vector Machine Classification of Drunk Driving Behaviour

Alcohol is the root cause of numerous traffic accidents due to its pharmacological action on the human central nervous system. This study conducted a detection process to distinguish drunk driving from normal driving under simulated driving conditions. The classification was performed by a support vector machine (SVM) classifier trained to distinguish between these two classes by integrating both driving performance and physiological measurements. In addition, principal component analysis was conducted to rank the weights of the features. The standard deviation of R–R intervals (SDNN), the root mean square value of the difference of the adjacent R–R interval series (RMSSD), low frequency (LF), high frequency (HF), the ratio of the low and high frequencies (LF/HF), and average blink duration were the highest weighted features in the study. The results show that SVM classification can successfully distinguish drunk driving from normal driving with an accuracy of 70%. The driving performance data and the physiological measurements reported by this paper combined with air-alcohol concentration could be integrated using the support vector regression classification method to establish a better early warning model, thereby improving vehicle safety.

The sensitivity of laboratory tests assessing driving related skills to dose-related impairment of alcohol: A literature review

Laboratory tests assessing driving related skills can be useful as initial screening tools to assess potential drug induced impairment as part of a standardized behavioural assessment. Unfortunately, consensus about which laboratory tests should be included to reliably assess drug induced impairment has not yet been reached. The aim of the present review was to evaluate the sensitivity of laboratory tests to the dose dependent effects of alcohol, as a benchmark, on performance parameters. In total, 179 experimental studies were included. Results show that a cued go/no-go task and a divided attention test with primary tracking and secondary visual search were consistently sensitive to the impairing effects at medium and high blood alcohol concentrations. Driving performance assessed in a simulator was less sensitive to the effects of alcohol as compared to naturalistic, on-the-road driving. In conclusion, replicating results of several potentially useful tests and their predictive validity of actual driving impairment should deserve further research. In addition, driving simulators should be validated and compared head to head to naturalistic driving in order to increase construct validity.