The relationship between blood alcohol concentration (BAC), age, and crash risk

Prevalence of alcohol-impaired driving: a systematic review with a gender-driven approach and meta-analysis of gender differences

BACKGROUND

A growing number of studies investigated the factors that contribute to driving under the influence (DUI) of alcohol in relation to gender. However, a gendered approach of the scientific evidence is missing in the literature. To fill this gap, a gender-driven systematic review on real case studies of the last two decades was performed. In addition to the gender of the drivers involved, major independent variables such as the period of recruitment, the type of drivers recruited, and the geographical area where the study was conducted, were examined. Afterwards, a meta-analysis was performed comparing alcohol-positive rates (APR) between male and female drivers in three subgroups of drivers: those involved in road traffic accidents, those randomly tested on the road, and volunteers.

METHODS

Three databases were searched for eligible studies in October 2023. Real-case studies reporting APR in man and women convicted for DUI of alcohol worldwide were included. Univariate analysis by ANOVA with post-hoc tests identified the independent variables with a significant impact on the dependent variable APR, according to a relationship subsequently investigated by standard multiple linear regression. The meta-analysis of random effects estimates was performed to investigate the change in overall effect size (measured by Cohen's d standardized mean difference test) and 95% confidence interval (CI).

RESULTS

Among papers addressing driver gender, univariate analysis of independent variables revealed a higher Alcohol Positive Rate (APR) in men, particularly in drivers involved in crashes, with a noticeable decrease over time. Analyzing the gender of drivers involved in crashes, the meta-analysis showed that men had a significantly higher APR (30.7%; 95%CI 26.8-35.0) compared to women (13.2%; 95%CI 10.7-16.1). However, in drivers randomly tested, there was no significant difference in APR between genders (2.1% for men and 1.4% for women), while in volunteers, there was a statistically significant difference in APR with 3.4% (95%CI 1.5-7.6) for men and 1.1% (95%CI 0.5-2.7) for women.

CONCLUSION

Despite a progressive decrease in the epidemiological prevalence of alcohol-related DUI over time, this phenomenon remains at worryingly high levels among drivers involved in road traffic accidents in both genders, with a higher prevalence in men. It's important for policymakers, professionals, and scientists to consider gender when planning research, analysis, interventions, and policies related to psychoactive substances, such as alcohol or other licit drugs. Forensic sciences can play a vital role in this regard, enabling a thorough analysis of gender gaps in different populations.

Wearable Alcohol Monitoring Device for the Data-Driven Transcutaneous Alcohol Diffusion Model

Wearable alcohol monitoring devices demand noninvasive, real-time measurement of blood alcohol content (BAC) reliably and continuously. A few commercial devices are available to determine BAC noninvasively by detecting transcutaneous diffused alcohol. However, they suffer from a lack of accuracy and reliability in the determination of BAC in real time due to the complex scenario of the human skin for transcutaneous alcohol diffusion and numerous factors (e.g., skin thickness, kinetics of alcohol, body weight, age, sex, metabolism rate, etc.). In this work, a transcutaneous alcohol diffusion model has been developed from real-time captured data from human wrists to better understand the kinetics of diffused alcohol from blood to different skin epidermis layers. Such a model will be a footprint to determine a base computational model in larger studies. Eight anonymous volunteers participated in this pilot study. A laboratory-built wearable blood alcohol content (BAC) monitoring device collected all the data to develop this diffusion model. The proton exchange membrane fuel cell (PEMFC) sensor was fabricated and integrated with an nRF51822 microcontroller, LMP91000 miniaturized potentiostat, 2.4 GHz transceiver supporting Bluetooth low energy (BLE), and all the necessary electronic components to build this wearable BAC monitoring device. The %BAC data in real time were collected using this device from these volunteers' wrists and stored in the end device (e.g., smartphone). From the captured data, we demonstrate how the volatile alcohol concentration on the skin varies over time by comparing the alcohol concentration in the initial stage (= 10 min) and later time (= 100 min). We also compare the experimental results with the outputs of three different input profiles: piecewise linear, exponential linear, and Hoerl, to optimize the developed diffusion model. Our results demonstrate that the exponential linear function best fits the experimental data compared to the piecewise linear and Hoerl functions. Moreover, we have studied the impact of skin epidermis thickness within ±20% and demonstrate that a 20% decrease in this thickness results in faster dynamics compared to thicker skin. The model clearly shows how the diffusion front changes within a skin epidermis layer with time. We further verified that 60 min was roughly the time to reach the maximum concentration, Cmax, in the stratum corneum from the transient analysis. Lastly, we found that a more significant time difference between BACmax and Cmax was due to greater alcohol consumption for a fixed absorption time.

A matched case-control analysis of autonomous vs human-driven vehicle accidents

Despite the recent advancements that Autonomous Vehicles have shown in their potential to improve safety and operation, considering differences between Autonomous Vehicles and Human-Driven Vehicles in accidents remain unidentified due to the scarcity of real-world Autonomous Vehicles accident data. We investigated the difference in accident occurrence between Autonomous Vehicles' levels and Human-Driven Vehicles by utilizing 2100 Advanced Driving Systems and Advanced Driver Assistance Systems and 35,113 Human-Driven Vehicles accident data. A matched case-control design was conducted to investigate the differential characteristics involving Autonomous' versus Human-Driven Vehicles' accidents. The analysis suggests that accidents of vehicles equipped with Advanced Driving Systems generally have a lower chance of occurring than Human-Driven Vehicles in most of the similar accident scenarios. However, accidents involving Advanced Driving Systems occur more frequently than Human-Driven Vehicle accidents under dawn/dusk or turning conditions, which is 5.25 and 1.98 times higher, respectively. Our research reveals the accident risk disparities between Autonomous Vehicles and Human-Driven Vehicles, informing future development in Autonomous technology and safety enhancements.

Risk of motor vehicle collision associated with cannabis and alcohol use among patients presenting for emergency care

BACKGROUND

The objective of this study was to examine the relationship between cannabis and alcohol use and occurrence of motor vehicle collision (MVC) among patients in the emergency department (ED).

METHODS

This was a cross-sectional study of visits to EDs in Denver, CO, Portland, OR, and Sacramento, CA by drivers who were involved in MVCs and presented with injuries (cases) and non-injured drivers (controls) who presented for medical care. We obtained blood samples and measured delta-9-THC and its metabolites. Alcohol levels were determined by breathalyzer or samples taken in the course of clinical care. Participants completed a research-assistant-administered interview consisting of questions about drug and alcohol use prior to their visit, context of use, and past-year drug and alcohol use. Multiple logistic regression was used to estimate the association between MVC and cannabis/alcohol use, adjusted for demographic characteristics. We then stratified participants based on levels of cannabis use and calculated the odds of MVC across these levels, first using self-report and then using blood levels for delta-9-THC in separate models. We conducted a case-crossover analysis, using 7-day look-back data to allow each participant to serve as their own control. Sensitivity analyses examined the influence of usual use patterns and driving in a closed (car, truck, van) versus open (motorcycle, motorbike, all-terrain vehicle) vehicle.

RESULTS

Cannabis alone was not associated with higher odds of MVC, while acute alcohol use alone, and combined use of alcohol and cannabis were both independently associated with higher odds of MVC. Stratifying by level of self-reported or measured cannabis use, higher levels were not associated with higher odds for MVC, with or without co-use of alcohol; in fact, high self-reported acute cannabis use was associated with lower odds of MVC (odds ratio [OR] 0.18, 95% confidence interval [CI] 0.05-0.65). In the case-crossover analysis, alcohol use alone or in combination with cannabis was associated with higher odds of MVC, while cannabis use alone was again associated with decreased odds of MVC.

CONCLUSIONS

Alcohol use alone or in conjunction with cannabis was consistently associated with higer odds for MVC. However, the relationship between measured levels of cannabis and MVC was not as clear. Emphasis on actual driving behaviors and clinical signs of intoxication to determine driving under the influence has the strongest rationale.

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.

Personality, perceptions and behavior: A study of speeding amongst drivers in Victoria, Australia

INTRODUCTION

Road crashes present a serious public health issue. Many people are seriously or fatally injured every year in avoidable crashes. While these crashes can have multiple contributing factors, including road design and condition, vehicle design and condition, the environment and human error, the performance of illegal driving behavior, including speeding, may also play a role. The current study aimed to examine the mediating influence that four potential deterrents (perceptions towards enforcement, crash risk, social norms and disapproval, and negative personal/emotional affect) have between the Big Five personality traits (conscientiousness; extraversion; agreeableness; neuroticism; openness) and expectations to speed.

METHODS

A total of 5,108 drivers in Victoria, Australia completed an online survey in 2019. A mediated regression analysis was used to examine pathways in a conceptual model developed for the study.

RESULTS

The results showed that perceptions towards the four potential deterrents examined did mediate the relationship (either completely or partially) between personality and expectations to speed.

CONCLUSIONS

The results of this study suggest that if interventions to deter illegal driving behavior are to be successful, one factor that could be taken into account is the personality traits of drivers who may be at greatest risk of the performance of illegal driving behaviors.

High-'n'-dry? A comparison of cannabis and alcohol use in drivers presenting to hospital after a vehicular collision

DESIGN

This was a prospective observational study.

BACKGROUND AND AIMS

The characteristics of cannabis-involved motor vehicle collisions are poorly understood. This study of injured drivers identifies demographic and collision characteristics associated with high tetrahydrocannabinol (THC) concentrations.

SETTING

The study was conducted in 15 Canadian trauma centres between January 2018 and December 2021.

CASES

The cases (n = 6956) comprised injured drivers who required blood testing as part of routine trauma care.

MEASUREMENTS

We quantified whole blood THC and blood alcohol concentration (BAC) and recorded driver sex, age and postal code, time of crash, crash type and injury severity. We defined three driver groups: high THC (THC ≥ 5 ng/ml and BAC = 0), high alcohol (BAC ≥ 0.08% and THC = 0) and THC/BAC-negative (THC = 0 = BAC). We used logistic regression techniques to identify factors associated with group membership.

FINDINGS

Most injured drivers (70.2%) were THC/BAC-negative; 1274 (18.3%) had THC > 0, including 186 (2.7%) in the high THC group; 1161 (16.7%) had BAC > 0, including 606 (8.7%) in the high BAC group. Males and drivers aged less than 45 years had higher adjusted odds of being in the high THC group (versus the THC/BAC-negative group). Importantly, 4.6% of drivers aged less than 19 years had THC ≥ 5 ng/ml, and drivers aged less than 19 years had higher unadjusted odds of being in the high THC group than drivers aged 45-54 years. Males, drivers aged 19-44 years, rural drivers, seriously injured drivers and drivers injured in single-vehicle, night-time or weekend collisions had higher adjusted odds ratios (aORs) for being in the high alcohol group (versus THC/BAC-negative). Drivers aged less than 35 or more than 65 years and drivers involved in multi-vehicle, daytime or weekday collisions had higher adjusted odds for being in the high THC group (versus the high BAC group).

CONCLUSIONS

In Canada, risk factors for cannabis-related motor vehicle collisions appear to differ from those for alcohol-related motor vehicle collisions. The collision factors associated with alcohol (single-vehicle, night-time, weekend, rural, serious injury) are not associated with cannabis-related collisions. Demographic factors (young drivers, male drivers) are associated with both alcohol and cannabis-related collisions, but are more strongly associated with cannabis-related collisions.

Alcohol consumption and all-cause and cause-specific mortality among US adults: prospective cohort study

BACKGROUND

Previous studies have shown inconsistent findings regarding the association of light to moderate alcohol consumption with cause-specific mortality. Therefore, this study sought to examine the prospective association of alcohol consumption with all-cause and cause-specific mortality in the US population.

METHODS

This was a population-based cohort study of adults aged 18 years or older in the National Health Interview Survey (1997 to 2014) with linkage to the National Death Index records through December 31, 2019. Self-reported alcohol consumption was categorized into seven groups (lifetime abstainers; former infrequent or regular drinkers; and current infrequent, light, moderate, or heavy drinkers). The main outcome was all-cause and cause-specific mortality.

RESULTS

During an average follow-up of 12.65 years, among the 918,529 participants (mean age 46.1 years; 48.0% male), 141,512 adults died from all causes, 43,979 from cardiovascular disease (CVD), 33,222 from cancer, 8246 from chronic lower respiratory tract diseases, 5572 from accidents (unintentional injuries), 4776 from Alzheimer's disease, 4845 from diabetes mellitus, 2815 from influenza and pneumonia, and 2692 from nephritis, nephrotic syndrome, or nephrosis. Compared with lifetime abstainers, current infrequent, light, or moderate drinkers were at a lower risk of mortality from all causes [infrequent-hazard ratio: 0.87; 95% confidence interval: 0.84 to 0.90; light: 0.77; 0.75 to 0.79; moderate 0.82; 0.80 to 0.85], CVD, chronic lower respiratory tract diseases, Alzheimer's disease, and influenza and pneumonia. Also, light or moderate drinkers were associated with lower risk of mortality from diabetes mellitus and nephritis, nephrotic syndrome, or nephrosis. In contrast, heavy drinkers had a significantly higher risk of mortality from all causes, cancer, and accidents (unintentional injuries). Furthermore, binge drinking ≥ 1 day/week was associated with a higher risk of mortality from all causes (1.15; 1.09 to 1.22), cancer (1.22; 1.10 to 1.35), and accidents (unintentional injuries) (1.39; 1.11 to 1.74).

CONCLUSIONS

Infrequent, light, and moderate alcohol consumption were inversely associated with mortality from all causes, CVD, chronic lower respiratory tract diseases, Alzheimer's disease, and influenza and pneumonia. Light or moderate alcohol consumption might also have a beneficial effect on mortality from diabetes mellitus and nephritis, nephrotic syndrome, or nephrosis. However, heavy or binge had a higher risk of all-cause, cancer, and accidents (unintentional injuries) mortality.

Learning about injury severity from no-injury crashes: A random parameters with heterogeneity in means and variances approach

The traditional approach to injury-severity analyses does not allow in-depth understanding of no-injury crashes, as crash factors found to contribute to the various injury severities may have similar effects on the severity of vehicle damage even if no injury is recorded. Viewing no-injury crashes using the vehicle damage severities as sub-categories and bases for potential injuries can improve understanding of future injury crashes. To better understand the mechanism of no-injury crashes and the crash factors that contribute to the extent of vehicle damage beyond the single categorization of these crashes in injury severity analysis, this study presents a vehicle damage severity analysis for no-injury crashes. To compare the effects of crash contributing factors on crash outcomes, two injury severity models were also estimated. Random parameters multinomial logit models with heterogeneity in means and variances were developed to account for unobserved heterogeneity. Model estimation results revealed that several common factors (e.g., unsafe speed, distracted driving, driving under influence, vehicle age, and run-off-road) are correlated with both injury severity in injury crashes and vehicle damage severity in no-injury crashes. Therefore, the sub-categorization of no-injury crashes by vehicle damage severity can potentially improve estimates of injury severity considered in resource allocation decisions for traffic safety.

The "Mellanby effect" in alcoholised e-scooter drivers

PURPOSE

Several studies tried to discuss and clarify the so-called Mellanby effect: Similar blood alcohol concentrations (BACs) supposedly lead to more signs of impairment in the phase of alcohol resorption than elimination. To assess this effect for alcoholised e-scooter driving, results of a real-driving fitness study were subanalysed.

METHODS

Sixteen subjects (9 females; 7 males) who completed runs at comparable BACs in the phases of alcohol resorption and elimination were chosen to assess a possible "Mellanby effect". The data of the subjects was taken from a prior e-scooter study by Zube et al., which included 63 subjects in total.

RESULTS

In the phase of alcohol resorption, the relative driving performance was approx. 92% of the phase of elimination (p value 0.21). Statistically significant more demerits were allocated to the obstacle "narrowing track" in the phase of resorption than elimination. Subjects also needed significantly more time to pass the obstacles "narrowing track", "driving in circles counterclockwise" and "thresholds" in the phase of resorption than elimination.

DISCUSSION

The most relevant obstacle to discriminate between the two different states of alcoholisation was the narrowing track. Insofar, measurements of the standard deviation of the lateral position (SDLP) might also be a sensitive component for the detection of central nervous driving impairment during shorter trips with an e-scooter. Additionally, driving slower during the phase of alcohol resorption seems to be the attempt to compensate alcohol-related deficits.

CONCLUSION

The results of the study suggest a slight Mellanby effect in e-scooter drivers.

Estimate of the magnitude of risky and protective behaviors associated with road traffic injuries in capitals participating in the Life in Traffic Project of Brazil

BACKGROUND

Brazil occupies the fifth position in the ranking of the highest mortality rates due to RTI in the world. With the objective of promoting traffic safety and consequently reducing deaths, Brazil created the Life in Traffic Project (LTP). The main goal of LTP is reducing 50% of RTI deaths, by promoting interventions to tackle risk factors, such as driving under the influence of alcohol and excessive and/or inappropriate speed. Thus, the aim of this study was to estimate the magnitude of risky and protective factors for RTI in capitals participating in the LTP in Brazil. We estimated these factors according to sociodemographic (age group, sex, education, race and, type of road user).

METHODS

A total of 5,922 car drivers and motorcyclists from 14 Brazilian capitals participating in the LTP were interviewed. Data collection was carried out in sobriety checkpoints at night and consisted of the administration of an interview and a breathalyzer test. Risky and protective behaviors associated with RTI were investigated. Covariates of the study were: age, sex, education, race and, type of road user. Poisson multiple regression analysis was used to assess the relationship between variables of interest.

RESULTS

The prevalence of individuals with positive blood alcohol concentration (BAC) was 6.3% and who reported driving after drinking alcohol in the last 30 days was 9.1%. The others risky behaviors reported were: driving at excessive speed on roads of 50 km/h, using a cell phone for calls while driving, using a cell phone to send or read calls while driving, running a red light. Use of seatbelts and helmets showed prevalence above 96,0% Use of seatbelts showed prevalence of 98.6% among car drivers, and helmet use was described by 96.6% of motorcycle drivers. Most risky behaviors were more prevalent in younger age groups (except BAC measurement higher in older participants), in males (except for cell phone use), in participants with higher education level and without a driver's license.

CONCLUSION

Excessive speed and driving under the influence of alcohol, defined as priorities within the LTP, need more consistent interventions, as they still have considerable prevalence in the cities investigated. The factors described such as cell phone usage and passing red traffic lights should also need to be prioritized as a focus on promoting traffic safety.

How did COVID-19 impact driving behaviors and crash Severity? A multigroup structural equation modeling

Risky driving behaviors such as speeding and failing to signal have been witnessed more frequently during the COVID-19 pandemic, resulting in higher rates of severe crashes. This study aims to investigate how the COVID-19 pandemic impacts the likelihood of severe crashes via changing driving behaviors. Multigroup structural equation modeling (SEM) is used to capture the complex interrelationships between crash injury severity, the context of COVID-19, driving behaviors, and other risk factors for two different groups, i.e., highways and non-highways. The SEM constructs two latent variables, namely aggressiveness and inattentiveness, which are indicated by risk driving behaviors such as speeding, drunk driving, and distraction. One great advantage of SEM is that the measurement of latent variables and interrelationship modeling can be achieved simultaneously in one statistical estimation procedure. Group differences between highways and non-highways are tested using different equality constraints and multigroup SEM with equal regressions can deliver the augmented performance. The smaller severity threshold for the highway group indicates that it is more likely that a crash could involve severe injuries on highways as compared to those on non-highways. Results suggest that aggressiveness and inattentiveness of drivers increased significantly after the outbreak of COVID-19, leading to a higher likelihood of severe crashes. Failing to account for the indirect effect of COVID-19 via changing driving behaviors, the conventional probit model suggests an insignificant impact of COVID-19 on crash severity. Findings of this study provide insights into the effect of changing driving behaviors on safety during disruptive events like COVID-19.

Evaluation of Driver's Reaction Time Measured in Driving Simulator

This article evaluates the driver’s reaction times in a driving simulator environment. The research focused mainly on young drivers under the age of 26, who cause many accidents. Each participating driver provided basic information later used for mathematical-statistical analysis. The main advantage of driving simulators is limitless usage. It is possible to simulate situations that would be unacceptable in real road traffic. Therefore, this study is also able to examine drunk driving. The main goal of the article is to evaluate if gender, practice, or alcohol significantly affected the reaction time of 30 drivers. We also focused on drinking before driving for a smaller number of the drivers; ten of them performed driving under the influence of alcohol. For these mathematical-statistical purposes, we used a one-sample t-test, a paired-samples t-test, an independent-sample t-test, and a correlation analysis together with the assessment of its statistical significance.

Lowering the legal alcohol limit in Belgium: Potential effects on the number of traffic victims

BACKGROUND

Since 1994, the legal limit of Blood Alcohol Concentration (BAC) is 0.5 g/L for the general drivers' population in Belgium. Since 2015, this limit has been lowered to 0.2 g/L for professional drivers. So far, no specific limitation has been adopted for novice drivers in Belgium. Recently, two bills were submitted to the House of Representatives: the first one proposed to impose a zero-limit for every driver, the second one proposed to restrict this zero-limit only to novice drivers.

OBJECTIVE

The present study evaluated the potential impact of the two bills that aim to reduce the legal BAC limit from 0.5 to zero, either for all drivers or for novice drivers only. We elaborated three scenarios related to the BAC categories for which lowering the legal BAC limit to zero would affect drink-driving behaviour: "Targeted BAC levels" scenario assumed that the new policy would impact only the specifically targeted BAC category, i.e., drivers in the category BAC below 0.5 g/L. "Extended impact" scenario corresponded to the "Targeted BAC levels" scenario to which we added a "halo effect" on drivers in the BAC category "0.5 g/L ≤ BAC < 0.8 g/L". "Broad range impact" scenario corresponded to the "Extended impact" scenario to where we extended the "halo effect" to drivers in the BAC category "0.8 g/L ≤ BAC < 1.2 g/L".

METHODS

The effect estimates were based on firstly, scientific literature on risks related to drink-driving at different BAC-levels, secondly data on crashes in Belgium and thirdly data on drink-driving behaviour in Belgium and in other European countries.

RESULTS

In case of a zero limit for all drivers, an annual reduction can be expected of 10 to 17 fatalities (i.e., a decrease of 2.4% to 3.9%), 8 to 20 severe injuries (i.e., a decrease of 0.3% to 0.8%) and 135 to 315 slight injuries (i.e., a decrease of 0.4% to 0.8%). In case a zero limit is only applied to novice drivers, an annual decrease can be expected by 2 to 4 fatalities (i.e., a decline of 3.7% to 6.2%), 8 to 16 serious injuries and 135 to 262 slight injuries (i.e., a decline of 1.7% to 3.2% in both cases).

DISCUSSION

There is no clear evidence on which of the three scenarios would be the most plausible. As the relative risk of a car crash increases strongly with the BAC level, the success of either measure will strongly depend on its ability to also affect drink driving at concentrations that are forbidden already. This also means that most of the casualties could be prevented if compliance with current rules increased.

Alcohol-related deaths among young passengers: An analysis of national alcohol-related fatal crashes

INTRODUCTION

There is consensus that riding with an impaired driver (RWI) constitutes a major threat to public health. The aim of this study was to characterize the factors contributing to the motor-vehicle deaths of 15-20 year-old (y/o) passengers that RWI with a peer.

METHOD

Secondary analyses of the 2010-2018 Fatality Analysis Reporting System. 5,673 passengers aged 15-20 y/o killed while riding in passenger cars with a driver aged 21 or older, 3,542 of these drivers also aged 15-20 y/o. Analyses were conducted between October 2019 and December 2020.

RESULTS

Sixty-three percent of the young passengers were killed while riding with a driver 15-20 y/o. Of these drivers, 26.8% had a blood alcohol concentration (BAC) >0.00 g/dL and 77.1% had a BAC ≥0.08 g/dL. Compared with those occurring during the day on weekdays, fatalities of young passengers who RWI with a peer driver with a BAC ≥ 0.08 g/dL often occurred on weekend nights (OR = 8.2) and weekday nights (OR = 5.2), and when the passenger and driver were both male (OR = 1.8). Race/ethnicity was not a significant contributor to RWI fatalities.

CONCLUSIONS

Most 15-20 y/o RWI fatalities occurred on weekends, at night, when the driver was a young peer with a high BAC, and the passenger and driver were male. The high prevalence of fatalities in these high-risk situations suggests that young driver-passenger dynamics may contribute to alcohol-related fatalities. Practical Applications: To curb RWI fatalities among underage passengers, countermeasures should focus not only on underage drinking drivers and riders, but also on drinking drivers of all ages. Prevention should increase focus on situations in which both the young passenger and young driver are males.

Survey and Synthesis of State of the Art in Driver Monitoring

Road vehicle accidents are mostly due to human errors, and many such accidents could be avoided by continuously monitoring the driver. Driver monitoring (DM) is a topic of growing interest in the automotive industry, and it will remain relevant for all vehicles that are not fully autonomous, and thus for decades for the average vehicle owner. The present paper focuses on the first step of DM, which consists of characterizing the state of the driver. Since DM will be increasingly linked to driving automation (DA), this paper presents a clear view of the role of DM at each of the six SAE levels of DA. This paper surveys the state of the art of DM, and then synthesizes it, providing a unique, structured, polychotomous view of the many characterization techniques of DM. Informed by the survey, the paper characterizes the driver state along the five main dimensions—called here “(sub)states”—of drowsiness, mental workload, distraction, emotions, and under the influence. The polychotomous view of DM is presented through a pair of interlocked tables that relate these states to their indicators (e.g., the eye-blink rate) and the sensors that can access each of these indicators (e.g., a camera). The tables factor in not only the effects linked directly to the driver, but also those linked to the (driven) vehicle and the (driving) environment. They show, at a glance, to concerned researchers, equipment providers, and vehicle manufacturers (1) most of the options they have to implement various forms of advanced DM systems, and (2) fruitful areas for further research and innovation.

Applications of brain imaging methods in driving behaviour research

Applications of neuroimaging methods have substantially contributed to the scientific understanding of human factors during driving by providing a deeper insight into the neuro-cognitive aspects of driver brain. This has been achieved by conducting simulated (and occasionally, field) driving experiments while collecting driver brain signals of various types. Here, this sector of studies is comprehensively reviewed at both macro and micro scales. At the macro scale, bibliometric aspects of these studies are analysed. At the micro scale, different themes of neuroimaging driving behaviour research are identified and the findings within each theme are synthesised. The surveyed literature has reported on applications of four major brain imaging methods. These include Functional Magnetic Resonance Imaging (fMRI), Electroencephalography (EEG), Functional Near-Infrared Spectroscopy (fNIRS) and Magnetoencephalography (MEG), with the first two being the most common methods in this domain. While collecting driver fMRI signal has been particularly instrumental in studying neural correlates of intoxicated driving (e.g. alcohol or cannabis) or distracted driving, the EEG method has been predominantly utilised in relation to the efforts aiming at development of automatic fatigue/drowsiness detection systems, a topic to which the literature on neuro-ergonomics of driving particularly has shown a spike of interest within the last few years. The survey also reveals that topics such as driver brain activity in semi-automated settings or neural activity of drivers with brain injuries or chronic neurological conditions have by contrast been investigated to a very limited extent. Potential topics in driving behaviour research are identified that could benefit from the adoption of neuroimaging methods in future studies. In terms of practicality, while fMRI and MEG experiments have proven rather invasive and technologically challenging for adoption in driving behaviour research, EEG and fNIRS applications have been more diverse. They have even been tested beyond simulated driving settings, in field driving experiments. Advantages and limitations of each of these four neuroimaging methods in the context of driving behaviour experiments are outlined in the paper.

Assessment of the impact of implementation of a zero blood alcohol concentration law in Uruguay on moderate/severe injury and fatal crashes: a quasi-experimental study

BACKGROUND AND AIMS

Debates regarding lowering the blood alcohol concentration (BAC) limit for drivers are intensifying in the United States and other countries, and the World Health Organization recommends that the limit for adults should be 0.05%. In January 2016, Uruguay implemented a law setting a zero BAC limit for all drivers. This study aimed to assess the effect of this policy on the frequency of moderate/severe injury and fatal traffic crashes.

DESIGN

A quasi-experimental study in which a synthetic control model was used with controls consisting of local areas in Chile as the counterfactual for outcomes in Uruguay, matched across population counts and pre-intervention period outcomes. Sensitivity analyses were also conducted.

SETTING

Uruguay and Chile.

CASES

Panel data with crash counts by outcome per locality-month (2013-2017).

INTERVENTION AND COMPARATOR

A zero blood alcohol concentration law implemented on 9 January 2016 in Uruguay, alongside a continued 0.03 g/dl BAC threshold in Chile.

MEASUREMENTS

Per-capita moderate/severe injury (i.e. moderate or severe), severe injury and fatal crashes (2013-2017).

FINDINGS

Our base synthetic control model results suggested a reduction in fatal crashes at 12 months [20.9%; P-value = 0.018, 95% confidence interval (CI) = -0.340, -0.061]. Moderate/severe injury crashes did not decrease significantly (10.2%, P = 0.312, 95% CI = -0.282, 0.075). The estimated effect at 24 months was smaller and with larger confidence intervals for fatal crashes (14%; P = 0.048, 95% CI = -0.246, -0.026) and largely unchanged for moderate/severe injury crashes (-9.4%, P = 0.302, 95% CI = -0.248, 0.058). Difference-in-differences analyses yielded similar results. As a sensitivity test, a synthetic control model relying on an inferior treatment-control match pre-intervention (measured by mean squared error) yielded similar-sized differences that were not statistically significant.

CONCLUSIONS

Implementation of a law setting a zero blood alcohol concentration threshold for all drivers in Uruguay appears to have resulted in a reduction in fatal crashes during the following 12 and 24 months.

Can't simply roll it out: Evaluating a real-world virtual reality intervention to reduce driving under the influence

Driving under the influence (DUI) increases the risk of crashes. Emerging technologies, such as virtual reality (VR), represent potentially powerful and attractive tools for the prevention of risky behaviours, such as DUI. Therefore, they are embraced in prevention efforts with VR interventions primed to grow in popularity in near future. However, little is known about the actual effectiveness of such DUI-targeting VR interventions. To help fill the knowledge gap, this study explored the effects of one VR intervention as delivered in the real world. Using pre and post test design, including an intervention group (n = 98) and a control group (n = 39), the intervention evaluation examined young drivers’ (aged 18 to 25, no known history of DUI) intention and self-reported behaviour three months after the intervention as compared to the baseline. The results did not provide evidence for statistically significant effects of the VR intervention on self-reported DUI behaviour during the three months post intervention and DUI intention at three months post intervention. Such results might be due to the fact that the recruited participants generally self-reported little DUI behaviour, i.e. positively changing behaviour that is already positive is inherently challenging. Nevertheless, the results question the utility of funding the roll-out of arguably attractive technologies without a thorough understanding of their effectiveness in particular settings. To improve the potential for future positive outcomes of such interventions, we provide suggestions on how VR software might be further developed and, subsequently, leveraged in future research to improve the likelihood for behavioural change, e.g. by collecting, analysing and presenting objective driving performance data. Alternatively, future endeavours might focus on participants with known DUI history and examine the effects of the VR intervention for this particular higher-risk group.

Driving under the influence of drugs or alcohol: Predicting the intentions of young drivers

Objectives: Driving under the influence (DUI) of drugs or alcohol impairs driving performance and, as a result, increases the risk of crashes. The risk of DUI is five-fold higher for young drivers (aged 18-25 years), but little is known about what determines their DUI intentions. This study applied an extended model of the Theory of Planned Behavior (TPB) to address the research question of what factors might influence young drivers' future intentions to DUI. Methods: This study used a survey obtaining data from 329 young drivers (Mage = 20.92 years, SD = 2.16) in Australia. Beyond the standard TPB measures of attitudes, subjective norms and perceived behavioral control (PBC), the current study included demographic variables and additional predictors (i.e., moral norm, peers' norm, perceived risk, impulsivity and past DUI behavior). Results: A vast majority of the participants (85.1%) selected the maximum (9, never), meaning that they had no intention to DUI in the future. Overall, a stepwise multilevel logistic regression analysis (Step 1: demographics, Step 2: TPB measures, and Step 3: additional predictors) explained between 30.1% and 52.9% of the variance in DUI intentions. It showed past DUI behavior as the strongest predictor of DUI intention, followed by instrumental attitude and descriptive norms. Conclusions: This study explored an extended TPB model to understand young drivers' DUI intentions better. With this new knowledge of understanding the factors that influence DUI, researchers and practitioners can create interventions and strategies that are better tailored to the population of young drivers at higher risk.

Predictors and burden of injury mortality in the Thai cohort study 2005-2015

BACKGROUND

Thailand is a high injury burden setting. In 2015 it had the world's second highest rate of road traffic fatalities. In order to develop strategies to reduce this burden an accurate understanding of the development of injury risk over the life course is essential.

METHODS

A national cohort of adult Thais was recruited in 2005 (n = 87,151). Participants completed a health questionnaire covering geodemographic, behavioural, health and injury data. Citizen ID numbers were matched with death registration records, identifying deaths from any injury. Adjusted logistic regression models were used to measure associations between baseline exposures and injury deaths between 2005 and 2015.

RESULTS

Injury mortality comprised 363 individuals, the majority (36%) from traffic injuries. Predictors of all-injury mortality were being male (AOR 3.55, 95% CI 2.57-4.89), Southern Thai (AOR 1.52, 95% CI 1.07-2.16), smoking (AOR 1.55, 95% CI 1.16-2.17), depression (AOR 1.78, 95% CI 1.07-2.96), previous injury (AOR 1.37, 95% CI 1.03-1.81) and drink driving history (AOR 1.37, 95%CI 1.02-1.85). Age and region of residence were stronger predictors for men, while anxiety/depression was a stronger predictor for women. Among males in the far south, assault caused the largest proportion of injury mortality, elsewhere traffic injury was most common.

CONCLUSIONS

This study identifies that a history of drink driving, but not regular alcohol consumption, increased injury risk. The associations between smoking and depression, and injury mortality also need further consideration.

Queer in the Heartland: Cancer Risks, Screenings, and Diagnoses among Sexual and Gender Minorities in Iowa

Little is known about the cancer experiences of sexual and gender minority (SGM) persons in Midwestern areas. In response, a statewide survey of 567 SGM adults in Iowa, a largely rural Midwestern state, assessed cancer prevalence, screening tests, and related risk factors. Skin cancer accounted for nearly half of reported cancers. Individuals assigned female sex at birth reported high levels of lifetime mammograms and Papanicolaou (Pap) tests. In contrast, there were almost no colorectal cancer screenings reported among older (age 50+) respondents, regardless of gender identity or sexual orientation. Current tobacco use was modest overall, and cisgender women were more likely to report heavy drinking than cisgender men. Cisgender men age 40 and younger were less likely to have any human papillomavirus vaccination than cisgender women. The survey identified both strengths to leverage and deficits to address, which may inform future cancer prevention efforts in Iowa and other Midwestern states.

Cannabis-impaired driving and Canadian youth

Acute cannabis use results in inattention, delayed information processing, impaired coordination, and slowed reaction time. Driving simulator studies and epidemiologic analyses suggest that cannabis use increases motor vehicle crash risk. How much concern should we have regarding cannabis associated motor vehicle collision risks among younger drivers? This article summarizes why young, inexperienced drivers may be at a particularly high risk of crashing after using cannabis. We describe the epidemiology of cannabis use among younger drivers, why combining cannabis with alcohol causes significant impairment and why cannabis edibles may pose a heightened risk to traffic safety. We provide recommendations for clinicians counselling younger drivers about cannabis use and driving.

Gender differences in driving control of young alcohol-impaired drivers

BACKGROUND

Male and female drivers exhibit different degrees of vehicle control while driving under the influence of alcohol. However, this interaction between alcohol and gender is understudied. The present study examined the effects of different alcohol levels on the driving control of male and female drivers with the help of driving simulator experiments in heterogeneous traffic conditions.

METHOD

Forty young drivers (20 males and 20 females) completed simulated driving at four Blood Alcohol Concentration (BAC) levels: 0% (control), 0.03%, 0.05% and 0.08%. Driving impairment in vehicle control was measured in terms of average speed, acceleration variability and reaction time of drivers. Repeated-measures ANOVA tests were conducted and regression models were developed for male and female drivers to quantify the effects of BAC levels and driver characteristics on the driving control measures.

RESULTS

Significant effects of gender were observed for average speed (p <  0.001) and acceleration variability (p = 0.015) but not for reaction time of drivers (p =  0.891). Further, the effect of BAC was significant in all the three measures of vehicle control (p <  0.001). Driving control improved with increasing age of male drivers while caffeine consumption was observed as an alcohol-antagonizing factor in female drivers.

CONCLUSION

The findings suggest that vehicle control of female drivers is more likely to get affected even at low BAC levels, providing evidence that they belong to critical section of driving community in terms of alcohol-related impairment. The findings may help in discouraging drinking and driving among male and female drivers.

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.

Impacts of graduated driver licensing regulations

We evaluate the impact of the Graduated Driver Licensing (GDL) system introduced in Victoria, Australia as they influence both injury and fatality rates. Since 1990, the Victorian GDL scheme has undergone several modifications including the introduction of new requirements and the stricter enforcement of existing regulations. Our evaluation of the GDL is based on monthly mortality and morbidity data for drivers 18-25 for the period January 2000 to June 2017. We estimate the immediate and long-term impacts of each policy change to the GDL system. Our results indicate that several initiatives in the GDL system have had impacts on both fatalities and injuries requiring hospitalisation when differentiated by gender. In a number of cases we observe that reactions to these measures are common to both genders. These include: the signalling of the proposed GDL changes in the media, the introduction of an extra probationary year for those under 21, the total alcohol ban for the entire probationary period, and limits on peer passengers for the first year. Stricter mobile phone restrictions appear to have had no impact on injuries for either males or females although they were associated with lower fatality rates for both. In addition, we found an indication that in the period prior to the introduction of the mandatory requirement of 120 h supervised driving, there was a rise in male driver injuries possibly caused by a rush of more inexperienced learners to obtain their probationary licence.

Breath tests in Western Australia: Examining the economic dividends and effectiveness of general deterrence

In this paper, we examine the relationship between traffic enforcement (in the form of roadside breath testing for alcohol) and traffic outcomes (alcohol-related traffic crashes) to identify an optimal point of traffic enforcement. In Western Australia (WA), Police are authorised to stop any driver and measure their blood alcohol concentration via a sample of their breath. Using a metric employed by Ferris et al. (2013) and a methodology analogous to that utilised by Cameron (2013), we model the relationship between alcohol related traffic crashes and the saturation of breath testing in WA from January 2008 to April 2018. Our analysis suggests that given the saturation of breath testing in 2018 (1.2 tests per licenced driver), a 10 % increase in breath testing would be associated with a decline of 0.34 alcohol related traffic crashes (ARTC) per 100,000 drivers per month, equating to six fewer crashes per month, state-wide. In addition, using 'willingness to pay' and human capital cost metrics to approximate the social costs of ARTC, we employ a cost-benefit analysis to estimate the point at which the social costs of ARTC equal the economic costs of breath tests. Our analysis suggests that an increase in the number of tests to 143 % of all licensed WA drivers (an increase of 450,000 breath tests from the 2017/18 financial year) would be anticipated to save the state AUD$13.3 million annually in the human capital costs of ARTC. Our findings suggest that a further increase in breath tests to 154% of all licensed WA drivers (an increase of 650,000 breath tests from 2017/18) may save the state AUD$31.0 million annually in willingness to pay costs. The analytics below present a novel combination of methods to approximate the relative economic merits of increases in traffic enforcement. Furthermore, the findings outlined here have practical applications for operational policing, while providing an analytical perspective for policy makers faced with making recommendations regarding the volume and saturation of breath tests.

Odds of culpability associated with use of impairing drugs in injured drivers in Victoria, Australia

Culpability analysis was conducted on 5000 drivers injured as a result of a vehicular collision and in whom comprehensive toxicology testing in blood was conducted. The sample included 1000 drivers for each of 5 years from approximately 5000-6000 drivers injured and taken to hospital in the State of Victoria. Logistic regression was used to investigate differences in the odds of culpability associated with alcohol and drug use and other selected crash attributes using the drug-free driver as the reference group. Adjusted odds ratios were obtained from multivariable logistic regression models in which other potentially explanatory driver and crash attributes were included. Drivers with alcohol present showed large increases in the odds of culpability similar to that seen in other studies investigating associations between blood alcohol concentration and crash risk. Methylamphetamine also showed a large increase in the odds of culpability (OR 19) compared to the reference group at both below and above 0.1 mg/L, whereas those drivers with Δ⁹-tetrahydrocannabinol (THC) present showed only modest increase in odds when all concentrations were assessed (OR 1.9, 95 %CI 1.2-3.1). Benzodiazepines in drivers also gave an increase in odds (3.2, 95 %CI 1.6-6.1), but not other medicinal drugs such as antidepressants, antipsychotics and opioids. Drivers that had combinations of impairing drugs generally gave a large increase in odds, particularly combinations of alcohol with THC or benzodiazepines, and those drivers using both THC and methamphetamine.

Potential for cannabis adaptation among participants in a drunk driving intervention

Background

Some alcohol interventions have been found to have the adverse outcome of increasing non-alcohol-related substance use. It is unknown, however, how changes in alcohol use over the course of alcohol ignition interlocks - a common DUI intervention - may impact other substance use.

Methods

Alcohol and cannabis use were measured using hair ethylglucuronide and Delta-9-Tetrahydrocannabinol concentrations in blood, respectively. Participants (N = 69) were measured at the interlock installation period and again 6-months later while the interlock was installed. A mixed ANOVA was conducted to examine changes in levels of ethanol and THC over time.

Results

On measures of marijuana use, there was a significant interaction effect between the group that increased alcohol use and time F(2, 66) = 7.863, p =.001; partial η ² =.192; as well as a main effect for time F(2, 66) = 21.106, p <.001; partial η ² =.242.

Conclusions

Installing interlocks may inadvertently increase cannabis use among those who decrease alcohol use. Crash risk associated with cannabis use is notably less than that of alcohol use, however, continued cannabis use may be problematic when the device is removed and alcohol use is expected to return to the higher pre-interlock levels.

Modeling head-on crash severity with drivers under the influence of alcohol or drugs (DUI) and non-DUI

Objective: The objective of this research is to identify and compare contributing factors to head-on crashes with drivers under and not under the influence of alcohol or drugs.Methods: The head-on crash data are collected from 2005 to 2013 in North Carolina from four aspects: vehicle, driver, roadway, and environmental characteristics. The final dataset includes 9,153 head-on crashes. A mixed logit model is developed to analyze the crash dataset involving drivers under and not under the influence of alcohol or drugs.Results: According to the obtained results, factors such as rural roadways, adverse weather, curve road, and high speed limit are among the most significant contributing factors to both head-on crashes with DUI and non-DUI. In addition, the results of this research demonstrate that high speed limit is found to be better modeled as random-parameters at specific injury severity levels for head-on crashes with DUI. Besides the factors mentioned above, dark light condition, old drivers, pickups, and motorcycles also significantly affect the severity of head-on crashes with non-DUI.Conclusions: The results of this study identify various factors that significantly affect the severity of head-on crashes with drivers under and not under the influence of alcohol or drugs. Also, the mixed logit model examines the heterogeneous effects and correlation in unobserved factors by allowing coefficients to be randomly distributed. The findings of this study call for more attention to head-on crashes and provide a reference for planners and engineers when developing and selecting countermeasures to reduce and/or mitigate head-on crashes.

Laboratory analysis of driving behavior and self-perceived physiological impairment at 0.03%, 0.05% and 0.08% blood alcohol concentrations

BACKGROUND

Alcohol-impaired driving is a critical factor leading to traffic crashes worldwide. Since decades, researchers from the developed nations have been investigating the effects of alcohol intoxication on their drivers. However, alcohol effects on the drivers of developing counties remain understudied. The extent of alcohol impairment may vary among the drivers of developed and developing nations due to the differences in drivers' physiology, driving conditions, drinking habits, policy enforcement and driving attitude.

METHODS

This study examined the effects of different Blood Alcohol Concentration (BAC) levels (0%, 0.03%, 0.05%, and 0.08%) on 75 licensed Indian drivers (56 males and 19 females) with the help of a fixed-base driving simulator. Subjects completed driving simulations for all the BAC levels in a driving environment representing heterogeneous traffic conditions. Performance measures included longitudinal and lateral driving control indicators (obtained from simulator) along with the self-reported physiological changes in the drivers (obtained from questionnaire) with varying BAC levels.

RESULTS

Mean speed was the only performance measure significantly affected at 0.03% BAC. At 0.05% BAC, mean speed and mean steering wheel angle were the two significantly impaired measures. At 0.08% BAC, all the driving performance measures showed significant impairment except steering wheel angle variability. Physiological characteristics of drivers deteriorated with rising BAC levels.

CONCLUSIONS

Alcohol significantly impaired the physiology of Indian drivers resulting in impairment in their driving performance. Mean speed was the only performance measure significantly affected by all the BAC levels, making it a suitable parameter to detect the alcohol-impaired state of the drivers.

Driving/riding after alcohol and marijuana use among young adults: Is residing with family protective?

Objective: Driving while impaired by alcohol or drugs increases the risk of motor vehicle fatalities, the leading cause of death among young adults. The current study documented the prevalence of driving after alcohol and marijuana use in the past 2 weeks as well as the prevalence of riding with a driver who had used each substance during that time frame. We tested whether young adults who lived with family members (i.e., their parents or their children) were less likely to engage in these behaviors. Methods: Participants aged 18-25 who resided in nonmetropolitan areas in the United States (N = 1,131; 55% female, M_age = 22.6) completed an online survey. Multivariate logistic regressions examined alcohol- and marijuana-related driving and riding behaviors adjusting for demographic factors. Interactions tested whether associations varied by gender. Results: In the 2 weeks prior to the survey, 17% of participants drove after drinking alcohol and 21% had ridden with a driver who had been drinking. The prevalence of driving after marijuana use was 11%, and 16% of the sample had ridden with a driver who had been using marijuana. Participants who lived with their parents were less likely to ride with a driver who had been using alcohol or marijuana (adjusted odds ratios [AORs] = 0.71 and 0.55, respectively). Living with parents was also associated negatively with driving after both substances, but these associations were no longer significant when controlling for substance use frequency and driving frequency. Surprisingly, the odds of driving after marijuana use were over 2 times larger for young adults who lived with their children. For women, but not men, residing with children decreased the odds of driving and riding after alcohol use. Conclusions: Living with parents protects against riding after substance use among young adults. Prevention programs should target young adults who live independently or those transitioning away from the parental home. Furthermore, given the higher rates of driving after marijuana use among young adult parents, this group should be educated about the risks associated with this behavior.

It Is More Than Just Alcohol: A Criminological Perspective on Routine Drinking Activities, Opportunity, and Alcohol-Related Crashes

This project expands on the “routine drinking activities” perspective by examining alcohol outlets, alcohol-related crashes, and theoretically derived contextual measures. Using census tract–level data from two U.S. cities, we draw on the prevention literature and routine activities theory to develop measures of alcohol availability and context. Spatially lagged regression models examined both direct and conditional relationships between alcohol outlets and alcohol-related crashes. Results indicate that the alcohol outlet and crash relationship was moderated by contextual factors (e.g., driving under the influence [DUI] enforcement and environmental hazards). Thus, alcohol availability may be just a part of a broader community system that affects the opportunity for alcohol-related crashes to occur.

Exploring the Effect of Driving Factors on Traffic Crash Risk among Intoxicated Drivers: A case Study in Wujiang

Intoxicated driving is a threat to both drivers and other road users. Exploring the association between intoxicated driving factors and traffic crashes is essential for taking effective countermeasures. Most previous works have studied the relation between intoxicated driving and traffic crash based on some large-sized cities. The current study aims to evaluate the effect of driving factors on traffic crashes among intoxicated drivers in a small-sized city in China. Descriptive statistics and binary logistic regression analysis are performed to guide the study, and the data (N = 1010) for the period 2016–2017 in Wujiang (i.e., a small-sized city in China) are employed as the target samples. The results demonstrate age, years of driving experience, road position, week, hour and blood alcohol concentration (BAC) are associated with traffic crashes in Wujiang. Specifically, the age of “18–25”, the years of driving experience of “≤2”, the “road intersection”, the “weekend”, the period of “0:00–6:59” and the BAC of “above 150 mg/100 mL” are more likely to cause traffic crashes among intoxicated drivers. The findings can be referred to make some targeted policies or measures to relieve Wujiang’s intoxicated driving situation and reduce the number of crashes caused by intoxicated driving.

Alcohol research with transgender populations: A systematic review and recommendations to strengthen future studies

BACKGROUND

There is a recent and growing research literature on alcohol use and related harms among transgender and other gender minority populations; however, current definitions and measures of hazardous drinking do not consider the complexity of physiological sex characteristics and socially constructed gender, raising doubts regarding their validity, applicability, and use with these populations. To address this, we reviewed current research on alcohol-related outcomes in transgender populations and critically summarized key issues for consideration in future research.

METHODS

We conducted a systematic review of transgender alcohol research in English language, peer-reviewed journals, published 1990-2017, and extracted key details (e.g., sample composition, alcohol measures, results).

RESULTS

Forty-four studies met all inclusion criteria for the review, the majority of which were conducted in the United States. The prevalence of hazardous drinking was high; however, estimates varied widely across studies. We noted frequent methodological weaknesses, including few attempts to differentiate sex and gender, poor attention to appropriate definitions of hazardous drinking, and reliance on cross-sectional study designs and non-probability sampling methods.

CONCLUSION

Given findings that suggest high need for ongoing public health attention, we offer recommendations to improve future alcohol studies with transgender and other gender minority populations, such as being explicit as to whether and how sex and/or gender are operationalized and relevant for the research question, expanding the repertoire of alcohol measures to include those not contingent on sex or gender, testing the psychometric performance of established screening instruments with transgender populations, and shifting from descriptive to analytic study designs.

Estimating the drink driving attributable fraction of road traffic deaths in Mexico

AIM

To estimate the Drink Driving Attributable Fraction (DDAF) of road traffic injury mortality in car occupants in Mexico during 2010-13.

DESIGN

A case-control study was conducted to examine the presence of alcohol in analysed body fluids of car occupants killed in fatal crashes (cases) compared with car drivers tested in alcohol-testing checkpoints who were not involved in a fatal collision (controls). Two data sets were used for the period 2010-13: the forensic module of the Epidemiological Surveillance System on Addictions that included car occupants killed in a collision (cases) and a data set from alcohol-testing at police checkpoints available for matching municipalities (controls).

SETTING

Mexico.

PARTICIPANTS

The analysed study sample included 1718 car occupants killed in a traffic collision and 80 656 drivers tested at alcohol police checkpoints, all from 10 municipalities.

MEASUREMENTS

Unadjusted and adjusted odds ratios (OR) of presence of alcohol in body fluids were obtained stratified by sex and age groups and the interaction with these two variables were assessed. The ORs were used to calculate the DDAF.

FINDINGS

It was estimated that 19.5% of car occupants' deaths due to road traffic injuries were attributable to alcohol consumption [95% confidence interval (CI) = 19.1-19.9]. The adjusted OR of presence of alcohol was 6.84 (95% CI = 6.06-7.71) overall. For males it was 7.21 (95% CI = 6.35-8.18) and for females it was 4.45 (95% CI = 3.01-6.60). The ORs were similar across younger age bands (10-19 years: 9.61, 95% CI = 6.72-13.73; 20-29 years: 7.70, 95% CI = 6.28-9.4; and 30-49 years: 7.21, 95% CI = 5.98-8.70); and lower but still elevated among older people (50+ years: 3.19, 95% CI = 2.19-4.65).

CONCLUSIONS

An estimated 19.5% of car occupant deaths in Mexico may have been caused by alcohol in 2010-13.

Emerging Adults Riding With Marijuana-, Alcohol-, or Illicit Drug-Impaired Peer and Older Drivers

OBJECTIVE

The purpose of this study was to examine the prevalence and covariates among emerging adults of riding with an impaired peer or older adult driver (RWI) because of marijuana (MJ), alcohol (ALC), or illicit drugs (ID).

METHOD

Data were from Waves 4 (W4, N = 2,085) and 5 (W5, N = 2,116) of the NEXT Generation Health Study, collected in 2013-2014, 1 and 2 years after high school. W5 RWI was specified for substance-specific impaired peer and older adult (peer/older adult) drivers. Multinomial logistic regressions estimated W5 association of substance-specific RWI with W4 RWI, and W5 heavy episodic drinking, MJ use, and school/residence/work status.

RESULTS

At W5, 33% of the participants reported RWI in the past year, including riding with ALC- (21%), MJ- (17%), and ID- (5%) impaired peer drivers and ALC- (2%), MJ- (4%), and ID- (0.7%) impaired older adult drivers. W4 RWI was associated with W5 RWI with impaired peer/older adult drivers for ALC- (adjusted odds ratio [AOR] = 4.28, 2.69) and MJ-RWI (AOR = 2.34, 3.56). W5 heavy episodic drinking was positively associated with W5 peer ALC-related RWI (AOR = 2.16) and peer/older adult MJ-related RWI (AOR = 2.38, 5.45). W5 MJ use was positively associated with W5 peer ALC-related RWI (AOR = 2.23), peer/older adult MJ-related (AOR = 10.89, 2.98), and peer/older adult ID-related (AOR = 9.34, 4.26) RWI. ID-related RWI was higher among those not attending 4-year college (AOR = 3.38), attending technology school (AOR = 16.23), living on their own (AOR = 6.85), or living on campus (AOR = 11.50).

CONCLUSIONS

The high prevalence of RWI among emerging adults occurred mostly with ALC- or MJ-impaired peer drivers. The findings support the need for precisely tailored programs to prevent impaired driving according to substance use and age.

One false move: A singular account of multiple outcomes arising from drink-driving

ISSUE ADDRESSED

To deconstruct a personal account involving the initial decision making and ultimate consequences of driving under the influence of alcohol to educate drinkers about the realities of short- and long-term impacts associated with drink-driving.

METHODS

This qualitative study uses collaborative methods and draws on an autoethnographic (n = 1) account to identify multiple challenges and outcomes arising from a singular drink-driving incident.

RESULTS

Findings document how the split-second decision to drink and drive can give rise to unforeseen, ongoing and complex problems associated with injuries and pain management, the legal system, personal and professional costs, social isolation and shame.

CONCLUSIONS

Many believe that driving ability is only affected if an individual is drunk, and that the ramifications of low-range drinking (blood alcohol concentration greater than 0.05 and less than 0.07) and driving are minimal and avoidable. This personal account emphasises the stark realities associated with such naïve perceptions, particularly among young males, and augments efforts to dissuade drivers from drinking. SO WHAT?: The experiential insights within this narrative account have the potential to help inform peer education programs and contribute to reductions in youth road trauma and associated injuries.

Cannabis and crash responsibility while driving below the alcohol per se legal limit

There is a growing interest in how extensively the use of marijuana by drivers relates to crash involvement. While cognitive, lab-based studies are consistent in showing that the use of cannabis impairs driving tasks, epidemiological, field-based studies have been inconclusive regarding whether cannabis use causes an increased risk of accidents. There is ample evidence that the presence of cannabis among drivers with a BAC≥0.08g/dL highly increases the likelihood of a motor vehicle crash. Less clear, however, is the contribution of cannabis to crash risk when drivers have consumed very little or no alcohol. This effort addresses this gap in knowledge. We took advantage of a unique database that merged fatal crashes in the California Statewide Integrated Traffic Records System (SWITRS) and the Fatality Analysis Reporting System (FARS), which allows for a precise identification of crash responsibility. To account for recent increase in lab testing, we restricted our sample to cover only the years 1993-2009. A total of 4294 drivers were included in the analyses. Descriptive analyses and logistic regressions were run to model the contribution of alcohol and drugs to the likelihood of being responsible in a fatal crash. We found evidence that compared with drivers negative for alcohol and cannabis, the presence of cannabis elevates crash responsibility in fatal crashes among drivers at zero BACs (OR=1.89) and with 0<BAC<0.05g/dL (OR=3.42), suggesting that emphasis on curbing impaired driving should not be solely focused on heavy-drinking drivers. Data limitations however caution about the generalizability of study findings. Special efforts to understand the effect of cannabis on fatal crashes, in particular in the absence of alcohol, are needed.

Self-reported driving under the influence of alcohol and cannabis among Ontario students: Associations with graduated licensing, risk taking, and substance abuse

OBJECTIVE

This article describes the patterns of self-reported driving under the influence of alcohol (DUIA) and driving under the influence of cannabis (DUIC) among licensed Ontario students in 2009 and examines their associations with graduated licensing, risk taking, and substance use problems for understanding DUIA and DUIC behaviors. Ontario's graduated licensing system requires new drivers to hold a G1 license for a minimum of 8 months and a G2 license for a minimum of 12 months before a full and unrestricted G license can be obtained. Among other restrictions, G1 drivers must maintain a 0 blood alcohol content (BAC), have an experienced driver in the passenger seat, not drive on any high-speed expressways, and not drive between the hours of midnight and 5 a.m. A G2 license is more similar to a G license, with fewer restrictions.

METHOD

This study analyzed data from the 2009 Ontario Student Drug Use and Health Survey (OSDUHS). The OSDUHS is a biennial population-based survey of students (grades 7 to 12) in Ontario, Canada.

RESULTS

The results showed that 16.3% of licensed students in Ontario reported DUIC and 11.5% reported DUIA during the past year. After controlling for the effect of age, type of license emerged as a robust predictor for both DUIA and DUIC behavior, because students with a G2 and full license were significantly more likely to report DUIA and DUIC than drivers with a G1 license. Multivariate analyses suggested that risk-seeking behaviors were more important for understanding DUIA behavior than for DUIC behavior. Elevated problem indicators for alcohol and for cannabis were associated with DUIA and DUIC, respectively.

CONCLUSIONS

Though much attention has been paid to drinking and driving among adolescents, this research shows that more Ontario students now report driving after cannabis use than after drinking alcohol. The results identify important correlates of both behaviors that may be useful for prevention purposes.

Frequent marijuana use and driving risk behaviours in Canadian youth

Background

A better understanding of the relations between patterns of marijuana use and driving risks in young adulthood is needed.

Methods

Secondary analyses of self-report data from the Victoria Healthy Youth Survey. Youth (baseline ages 12 to 18; N=662; 52% females) were interviewed biannually (on six occasions) from 2003 to 2013 and classified as abstainers (i.e., used no marijuana in past 12 months), occasional users (i.e., used at most once per week), and frequent users (i.e., used more than once a week).

Results

In the frequent user group, 80% of males and 75% of females reported 'being in a car driven by driver (including themselves) using marijuana or other drugs in the last 30 days', 64% of males and 33% of females reported that they were 'intoxicated' with marijuana while operating a vehicle and 50% of males and 42% of females reported being in a car driven by a driver using alcohol. In addition, 28% of occasional users and also a small proportion of abstainers reported 'being in a car driven by a driver using marijuana or other drugs in the last 30 days'.

Interpretation

The high frequency of driving risk behaviours, particularly for frequent users, suggest that plans for legalization of recreational use should anticipate the costs of preventive education efforts that present an accurate picture of potential risks for driving. Youth also need to understand risks for dependence, and screening for and treatment of marijuana use disorders is needed.

Analysis of risk factors affecting driver injury and crash injury with drivers under the influence of alcohol (DUI) and non-DUI

OBJECTIVE

The objective of this research was to study risk factors that significantly influence the severity of crashes for drivers both under and not under the influence of alcohol.

METHODS

Ordinal logistic regression was applied to analyze a crash data set involving drivers under and not under the influence of alcohol in China from January 2011 to December 2014.

RESULTS

Four risk factors were found to be significantly associated with the severity of driver injury, including crash partner and intersection type. Age group was found to be significantly associated with the severity of crashes involving drivers under the influence of alcohol. Crash partner, intersection type, lighting conditions, gender, and time of day were found to be significantly associated with severe driver injuries, the last of which was also significantly associated with severe crashes involving drivers not under the influence of alcohol.

CONCLUSIONS

This study found that pedestrian involvement decreases the odds of severe driver injury when a driver is under the influence of alcohol, with a relative risk of 0.05 compared to the vehicle-to-vehicle group. The odds of severe driver injury at T-intersections were higher than those for traveling along straight roads. Age was shown to be an important factor, with drivers 50-60 years of age having higher odds of being involved in severe crashes compared to 20- to 30-year-olds when the driver was under the influence of alcohol. When the driver was not under the influence of alcohol, drivers suffered more severe injuries between midnight and early morning compared to early nighttime. The vehicle-to-motorcycle and vehicle-to-pedestrian groups experienced less severe driver injuries, and vehicle collisions with fixed objects exhibited higher odds of severe driver injury than did vehicle-to-vehicle impacts. The odds of severe driver injury at cross intersections were 0.29 compared to travel along straight roads. The odds of severe driver injury when street lighting was not available at night were 3.20 compared to daylight. The study indicated that female drivers are more likely to experience severe injury than male drivers when not under the influence of alcohol. Crashes between midnight and early morning exhibited higher odds of severe injury compared to those occurring at other times of day. The identification of risk factors and a discussion on the odds ratio between levels of the impact of the driver injury and crash severity may benefit road safety stakeholders when developing initiatives to reduce the severity of crashes.

Marijuana-, alcohol-, and drug-impaired driving among emerging adults: Changes from high school to one-year post-high school

INTRODUCTION

Driving while impaired (DWI) increases the risk of a motor vehicle crash by impairing performance. Few studies have examined the prevalence and predictors of marijuana, alcohol, and drug-specific DWI among emerging adults.

METHODS

The data from wave 3 (W3, high school seniors, 2012, N=2407) and wave 4 (W4, one year after high school, N=2178) of the NEXT Generation Health Study with a nationally representative cohort. W4 DWI (≥1day of past 30days) was specified for alcohol-specific, marijuana-specific, alcohol/marijuana-combined, illicit drug-related DWI. Multinomial logistic regression models estimated the association of W4 DWI with W3 covariates (perceived peer/parent influence, drinking/binge drinking, marijuana/illicit drug use), and W4 environmental status variables (work/school/residence) adjusting for W3 overall DWI, demographic, and complex survey variables.

RESULTS

Overall DWI prevalence from W3 to W4 changed slightly (14% to 15%). W4 DWI consisted of 4.34% drinking-specific, 5.02% marijuana-specific, 2.41% drinking/marijuana combined, and 3.37% illicit drug-related DWI. W3 DWI was significantly associated with W4 alcohol-related and alcohol/marijuana-combined DWI, but not other DWI. W3 marijuana use, binge drinking, and illicit drug use were positively associated with W4 marijuana-specific, alcohol/marijuana-combined, and illicit drug-related DWI, respectively. W3 friend drunkenness and marijuana use were positively associated with W4 alcohol-specific and marijuana-related DWI, respectively. W3 peer marijuana use was negatively associated with W4 alcohol-specific DWI.

CONCLUSIONS

Driving under the influence of alcohol, marijuana, and illicit drugs is a persistent, threatening public health concern among emerging U.S. adults. High school seniors' binge drinking as well as regular alcohol drinking and marijuana/illicit drug use were independently associated with respective DWI one year after high school. Peer drunkenness and marijuana use in high school may be related to subsequent DWI of emerging adults.

PRACTICAL APPLICATIONS

The results support the use of injunctive peer norms about getting drunk and smoking marijuana in guiding the development of prevention programs to reduce youth DWI.

Personal determinants of acceptance of drinking and driving among Polish drivers

<b>Background</b><br /> <br /> The aim of the study was to explore a number of personal predictors that increase one’s approval of driving under the influence (DUI). In keeping with the previous studies, we assumed this approval will more often be expressed by unmarried young men with a lower level of education, who are additionally characterized by a higher need for stimulation, risk acceptance, sensation seeking, and a preference for hedonic values.<br /> <br /> <b>Participants and procedure</b><br /> <br /> After examining more than 1000 drivers, we selected a group of 254 individuals (97 men, 157 women) who formed our study group. In our survey, these drivers admitted to driving while intoxicated in the past, but at the same time declared that small doses of alcohol did not limit their driving skills. We used a set of research tools in order to verify the assumptions. The following tools measured temperamental and personality variables: Formal Characteristics of Behavior-Temperament Inventory, Risk Acceptance Scale, Stimulating-Instrumental Risk Inventory, Scheler Value Scale, Rotter’s Locus of Control Scale, and Zuckerman’s Sensation Seeking Scale.<br /> <br /> <b>Results</b><br /> Driving under the influence of alcohol is most often approved of by unmarried men who have a higher level of education and are characterized by low levels of sensory sensitivity, low levels of emotional reactivity, an internal locus of control, a high need for risks, high sensation-seeking tendencies, and who prefer vital and aesthetic values.<br /> <br /> <b>Conclusions</b><br /> It is well justified to examine personal predictors of various dangerous road behaviors, such as driving under the influence of intoxicating substances. These studies could aid both creating effective social prevention programs and conducting psychological screening tests.

Prevalence of alcohol and drug use in injured British Columbia drivers

OBJECTIVES

Determine the prevalence of drug use in injured drivers and identify associated demographic factors and crash characteristics.

DESIGN

Prospective cross-sectional study.

SETTING

Seven trauma centres in British Columbia, Canada (2010-2012).

PARTICIPANTS

Automobile drivers who had blood obtained within 6 h of a crash.

MAIN OUTCOME MEASURES

We analysed blood for cannabis, alcohol and other impairing drugs using liquid chromatography/mass spectrometry (LCMS).

RESULTS

1097 drivers met inclusion criteria. 60% were aged 20-50 years, 63.2% were male and 29.0% were admitted to hospital. We found alcohol in 17.8% (15.6% to 20.1%) of drivers. Cannabis was the second most common recreational drug: cannabis metabolites were present in 12.6% (10.7% to 14.7%) of drivers and we detected Δ-9-tetrahydrocannabinol (Δ-9-THC) in 7.3% (5.9% to 9.0%), indicating recent use. Males and drivers aged under 30 years were most likely to use cannabis. We detected cocaine in 2.8% (2.0% to 4.0%) of drivers and amphetamines in 1.2% (0.7% to 2.0%). We also found medications including benzodiazepines (4.0% (2.9% to 5.3%)), antidepressants (6.5% (5.2% to 8.1%)) and diphenhydramine (4.7% (3.5% to 6.2%)). Drivers aged over 50 years and those requiring hospital admission were most likely to have used medications. Overall, 40.1% (37.2% to 43.0%) of drivers tested positive for alcohol or at least one impairing drug and 12.7% (10.7% to 14.7%) tested positive for more than one substance.

CONCLUSIONS

Alcohol, cannabis and a broad range of other impairing drugs are commonly detected in injured drivers. Alcohol is well known to cause crashes, but further research is needed to determine the impact of other drug use, including drug-alcohol and drug-drug combinations, on crash risk. In particular, more work is needed to understand the role of medications in causing crashes to guide driver education programmes and improve public safety.

The Effect of Perceived Risk on the Combined Used of Alcohol and Marijuana: Results from Daily Surveys

Background

Studies looking at the association between perceived risk and simultaneous use of alcohol and marijuana are scarce. The present study has three purposes: (1) to examine the association between alcohol and marijuana use at the daily level; (2) to document how this association varies by the perceived risk of using alcohol and marijuana simultaneously; (3) to test whether the association varies by college attendance.

Methods

89 young adults (Mean Age = 18.3 years, SD = 0.5) participated between October 2012 and May 2013. Participants completed a 30-min survey followed by 14 brief daily surveys in each of three waves.

Results

Alcohol use on a given day was associated with increased odds of marijuana use that day, especially among young adults with lower perceived risk. For college students, the association between alcohol and marijuana was weaker than for non-students.

Conclusions

Alcohol and marijuana use were associated at a daily level, especially among young adults with lower perceived risk and those who were not attending college.

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Alcohol use on a given day was associated with higher odds of marijuana use that day.

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The alcohol and marijuana link was stronger for participants with low perceived risk.

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The daily alcohol and marijuana association was weaker for college students.

Drinking Patterns and HIV Risk Behaviors Among Black and Latino Men Who Have Sex Within Los Angeles County

Alcohol, the most widely used substance among men who have sex with men (85%), remains an important factor in HIV research among this high-risk population. However, research on alcohol use among Black and Latino men who have sex with men (BLMSM), a population disproportionately affected by HIV in the United States, is limited and inconclusive. This study explored sociodemographic and HIV risk with daily heavy and low-risk drinking patterns among BLMSM. BLMSM (N = 188) aged 18 to 40 years were recruited through social media, local colleges, heteronormative clubs, private men’s groups, gay establishments, and organized events in Los Angeles County. Participants completed self-administered questionnaires. Fisher’s exact tests revealed significant relationships between drinking patterns and condomless insertive anal intercourse (p = .001), race (p < .001), age (p = .02), and perception of alcohol-related HIV risk (p = .007). The Fisher’s exact tests findings for age held true in the multiple regression model (p = .014). Findings suggest that BLMSM who engage in higher risk drinking also engage in alcohol-related HIV risk. Culturally competent interventions should consider including a combined focus to explore the synergy between risky drinking patterns and HIV risk among BLMSM.