Cannabis Adaptation During and After Alcohol Ignition Interlock Device Installation: A Longitudinal Study.

OBJECTIVE: A common intervention to prevent alcohol-impaired driving are alcohol ignition interlock devices (IIDs), which prevent drivers with a blood alcohol concentration greater than .025% from starting the car. These devices force drivers to adapt their drinking to accommodate the device. Prior studies indicated a transfer of risk as some drivers with an IID may increase cannabis use as they decrease alcohol use. This study examines whether this increase in cannabis use persists after IID removal when alcohol use reverts to pre-IID levels. METHOD: The data are from the Managing Heavy Drinking (MHD) study of drivers in New York State. The MHD is a comprehensive three-wave study of drivers convicted of driving under the influence from 2015 to 2020. Participants (N = 189) completed all waves, and provided oral fluid/blood and hair samples to measure cannabis and alcohol use, respectively. Mixed between-within analysis of variance was conducted to assess cannabis use at IID installation (Time 1), removal (Time 2), and at 6-month follow-up (Time 3). RESULTS: In aggregate, participants increased their cannabis use over the course of the study. Drivers who decreased their alcohol use while the IID was installed on their car significantly increased their cannabis use while the IID was in place and further increased cannabis use after the device's removal. CONCLUSIONS: IIDs are efficacious in preventing alcohol-impaired driving. However, in some cases, they may have the unintended effect of increasing other substance use. The current study outlines the need for supplemental treatment interventions while on IID to prevent a transfer of risk to other substances, or polysubstance use after the device is removed.

Examining the role of trauma in alcohol interlock performance: A structural pathway analysis.

OBJECTIVE: Self-medication using alcohol is a common coping response among individuals dealing with trauma as is driving under the influence of alcohol (DUI). A common intervention for drivers convicted of DUI, is an alcohol ignition interlock device (IID)-which requires breath samples before starting the car. If the sample is above a predetermined limit (.025), the car will not start, thus preventing impaired driving. IIDs are an effective intervention to reduce rates of drinking and driving among high risk populations; however, limited research has examined how traumatic experiences may impact performance on IIDs. METHODS: This study is an archival analysis of the Managing Heavy Drinking (MHD) study of drivers in New York state. The MHD is a comprehensive study of drivers convicted of a DUI from 2015-2020. Participants (N = 121) completed questionnaires and provided consent to retrieve information from interlock providers. Outcome variable included high BAC lockout ratios (number of high BAC lockouts [BAC>.08]/number of clean blows [BAC ≤ .025]). Other variables included demographic variables, alcohol treatment history, trauma experiences, and prior DUI history. Variables were entered into a structural equation model. RESULTS: In the final structural model, pathways that demonstrated a p-value of greater than .10 were dropped from the model. This produced acceptable overall model fit statistics (χ2 = 27.059(10), p=.003; CFI = .900; NFI = .898; RMSEA = .063). A significant pathway was found from the trauma measure to alcohol use (ß = .132), and from alcohol use to interlock performance (ß = .636). However, no significant relationship was found between trauma and interlock performance other than through alcohol use. CONCLUSIONS: The current study provides a useful framework upon which to understand the role traumatic experiences have on alcohol IID performance. Traumatic experiences are in of themselves insufficient to impact IID performance directly, but it may indirectly impact IID performance through increasing alcohol use.

A Latent Class Analysis of DUI Offender Motivation and Awareness as Predictors of Performance While on Alcohol Ignition Interlocks.

INTRODUCTION: Alcohol ignition interlock devices (IID) reduce rates of drinking and driving. The interlock offers an opportune time for tailoring targeted interventions to develop habits to separate drinking from driving among this high-risk population. This study identified different types of IID users upon whom targeted interventions could be developed. METHODS: Participants (N = 114) were assessed at IID installation and again six months later. Latent class analysis (LCA) was conducted using drinking environment, drinking motivation, social support, drug use, and problem drinking behaviors as indicators. Multivariate regression analyses were conducted comparing latent class assignment with impaired driving attempts. RESULTS: LCA supported a 4-class model where 14.8% of participants fell into the low use/high awareness class; 30.6% fell into the heavy use/high awareness class; 30.6% fell into the mixed use/high awareness class; and 24.0% fell into the moderate use/low awareness class. Drivers in the moderate use/low awareness condition had increased early morning BAC lockouts. CONCLUSIONS: These typologies demonstrate important differences within high risk drivers. Indeed, drivers who fell into the moderate use/low awareness class may not have considered their alcohol-related behaviors problematic. This information could lend itself to the development of targeted interventions to address subgroups of drinking drivers.

Convicted drinking and driving offenders: Comparing alcohol use before and after the pandemic outbreak.

BACKGROUND: Before the COVID-19 pandemic, very little was known about the impact of social isolation on individuals' alcohol use and misuse. This study examines how socially isolated individuals with a history of heavy drinking used alcohol during the pandemic. METHODS: Data for this study came from an add-on to the Managing Heavy Drinking (MHD) longitudinal study of drivers convicted of DWI that was conducted in Erie County, New York. Pre-COVID information (October 2019-March 2020) was augmented with a COVID-19 questionnaire collected between July and August 2020. A total of 92 participants completed the COVID-19 survey. RESULTS: The sample of problem drinkers showed a significant increase after the pandemic outbreak in the average number of drinking days from 1.99 to 2.49 per week (p = 0.047), but a significant decrease in the average number of drinks per drinking day, from 3.74 to 2.74 (p = 0.003). The proportion of individuals who drank more frequently was greater among those who, before the outbreak had an Alcohol Use Disorders Identification Test (AUDIT) score <8 (26% increase) compared with those with an AUDIT score of >8 (13%). Alcohol treatment was also associated with the frequency of drinking, with individuals who were not in alcohol treatment showing a 16% increase in frequency compared with a 10% increase among those in treatment. Further, individuals who, after the outbreak worried about their health (30%) or finances (37%) reported greater increases in the frequency of drinking than those who did not worry about their health (17%) or finances (10%). CONCLUSIONS: Overall, the individuals in our sample showed small changes in the frequency andheaviness of drinking after the outbreak of COVID-19, effects that opposite in direction from one another and thus resulted in no overall change in drinks consumed. Nonetheless, we identified factors that influenced the effects of the pandemic on drinking behavior among individuals convicted of DWI, which emphasizes the need to individualize these individuals' treatment, particularly in the context of dramatic environmental change.

Changes in Alcohol Use and Drinking and Driving Outcomes From Before Arrest for Driving Under the Influence to After Interlock Removal.

BACKGROUND: Half of the offenders convicted of impaired driving in the United States are sentenced to install alcohol ignition interlock devices (IIDs), which prevent them from starting their vehicles if they have been drinking. No research has yet explored offenders' patterns of alcohol consumption and driving under the influence of alcohol (DUI) from the time before the arrest to the time period after the IID is installed. This study aims to fill that gap in knowledge. METHODS: Using the Timeline Follow-back interview procedure, we assessed the daily drinking of 153 convicted DUI offenders' self-reported total alcohol consumption and rates of self-reported driving after drinking over 4 phases: before DUI arrest, between arrest and IID installation, during the phase on the interlock, and after the interlock is removed. Because information about behaviors in each period was not available for every participant, comparisons were made using paired-sample contrasts. RESULTS: Compared with before the arrest, total alcohol use decreased by 50% in the 4-month phase following arrest and before IID installation, though it did not change much afterward. The frequency of drinking and driving decreased sharply after the arrest (-82%), with further decrease upon installation of the interlock (-58%, p = 0.05). The frequency of drinking and driving after the IID was removed returned to preinstallation drinking and driving status (+58%, p = 0.01). CONCLUSIONS: Participants made significant adjustments to their drinking behavior by adhering to the traditional DUI driving restrictions in the postarrest phase. Although installation of an IID was not associated with a significant change in drinking, it further reduced the frequency of drinking and driving. Evaluations of the IID experience should take into account information on an individual's drinking and DUI behaviors not only before the IID was installed, but before the individual was arrested.

Understanding non-installers of the ignition interlock device: A qualitative analysis.

INTRODUCTION: Literature notes the efficacious use of alcohol ignition interlock devices (IID) in reducing rates of drinking and driving while installed on the vehicle. Some drivers who are convicted of driving while intoxicated (DWI) elect to have their license suspended/revoked instead of installing the device. These individuals represent a high-risk subsample of drivers, yet limited literature has addressed this concern. The current study seeks to fill this gap using qualitative interviews addressing: (i) why do non-installers make the choice to not install a mandated IID; and (ii) how are non-installers managing without the IID? METHODS: The study utilises the Managing Heavy Drinkers study of drivers in Erie County, New York, USA. Participants were purposively sampled from a group of non-installers (n = 6; four females, two males) who completed semi-structured interviews. Constructed grounded theory was used to develop a theoretical understanding of participant's experiences. RESULTS: To understand why participants elect not to install the IID, thematic analysis revealed: alleviating constraints, predominantly the financial burdens associated with an IID, and institutional mistrust. Additionally, data revealed that participants are managing without the IID by mitigating apprehension. This included driving cautiously to avoid detection and utilising alternative transportation. DISCUSSION AND CONCLUSIONS: This study furthers understanding of why drivers convicted of a DWI elect not to install an IID. Future research should seek to identify barriers to IID installation. This work provides evidence for establishing institutional protocols that ensure drivers convicted of a DWI receive consistent and correct information about the IID process.

Typologies of Drivers Convicted of Driving Under the Influence of Alcohol as Predictors of Alcohol Ignition Interlock Performance.

Background: Alcohol ignition interlock devices (IIDs) reduce rates of drinking and driving when installed on the vehicles of offenders. While the IID is installed on their vehicle, some drivers adapt their drinking behaviors, while others cannot. Heavy alcohol use and mental health concerns reduce treatment adherence in clinical settings, but it has not yet known how they pertain to behavioral adaptation to IIDs. Objectives: This study focuses on identifying driver typologies as predictors of performance while on alcohol IIDs. Methods: The study utilizes the Managing Heavy Drinking study of drivers in New York state. Participants (N = 101; 59 males, 42 females) completed questionnaires assessing demographic information, drinking behaviors, driving history and mental health measures. All participants had been convicted of a DUI, and installed an IID. Latent class analysis was used to establish typologies and predict lockout ratios. Results: Four typologies emerged and drivers with elevations in mental health concerns had significantly worse lockout ratios than those in other classes. Conclusions: The current study may provide support for interventions designed to identify drivers with comorbid mental health concerns and tailor appropriate interventions to administer while the IID is installed with the aim of improving behavioral adaptation to the device.

The impact of interlock installation on driving behavior and drinking behavior related to driving.

OBJECTIVE: There is a substantial body of evidence that the recidivism of impaired-driving offenders is reduced while an ignition interlock device (IID) is on their vehicles. This study examines changes in driving behaviors and drinking behaviors used by DWI offenders to manage driving with the IID. METHODS: A total of 166 IID participants who completed two surveys covering the period from arrest to IID installation (T1) and during IID use (T2) were examined. Four domains were covered: demographics, driving environments and transportation needs, reported driving activity, and reported drinking activities. Participants were on average 38 years old, 43% were female, 35% completed college, 34% had an income of more than $50,000, and 83% were employed. For those who provided it, the mean blood alcohol content (BAC) at arrest was .184 g/dL, with only 8 (5%) individuals below .08 g/dL, and 93 (56%) at over .18 g/dL. About 45% were repeat DWI offenders. RESULTS: Between T1 and T2 there was a slight increase in acknowledging public transportation was available (p=.001), an increase in other individuals driving the interlock-equipped vehicle (p=.002), an increase in the number of vehicles in the household not registered to the DWI offender (p< .001), and an increase in the number of participants who reported that driving was important to their lifestyle (p=.008). Initial (T1) expectations about whether the interlock would be a problem were significantly different from actual experiences reported in T2 (p<.001). With respect to alcohol consumption, 14% reported abstinence at T2 compared to 2% at T1 (p=.001) and the number of drinks per drinking occasion decreased from a mean of 4.90 at T1 to 3.14 at T2 (p=.001), but the number of drinking occasions increased by a third (p=.003). The number of drinking locations (p=.001), the frequency of stopping after work for a drink (p=.001), and drinking at a bar all decreased (p<.001). CONCLUSIONS: Interlock users make some adjustments in how they drink, the amount they drink, and where they drink. This finding suggests that there may be methods that can be used to extend the benefits of the IID beyond the sanction period.

Driver experiences with the alcohol ignition interlock: Comparing successful and poor performers.

OBJECTIVES: The purpose of this investigation was to compare the drinking patterns and experiences (both positive and negative) among DUI offenders who had installed an ignition interlock. The association between those experiences and interlock performance as measured by the number of times they had a lockout, was also assessed. METHODS: Over 300 DUI offenders who installed an interlock in the State of Florida were recruited and completed an on-line survey at the beginning and end of their interlock restriction. A record of the interlock performance data from each was downloaded and used to determine how many lockouts they experienced during their interlock restriction period. Offenders were defined into two groups; successful cases (having 0 or 1 lockout) or poor performers (have 2 or more lockouts). Chi-square and binary regressions were used to assess differences between groups. RESULTS: Poor performers reported significantly more drinking and were more likely to drink in a context of emotional comfort, yet they were more likely to report positive experiences with the interlock, especially as to its ability to remind them to avoid another DUI by reducing their drinking and driving. No difference was found between these two groups for the interlock's ability to reduce drinking. CONCLUSIONS: People with a more serious drinking pattern and who may be most at risk for recidivating may be more inclined to recognize the potential benefits of the interlock as a DUI preventive countermeasure. More research is needed to identify and influence high risk DUI offenders while on the interlock to increase its effectiveness once the interlock is removed.

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.

Alcohol-Related Risk of Driver Fatalities in Motor Vehicle Crashes: Comparing Data From 2007 and 2013-2014.

OBJECTIVE: Using data from 2013-2014, this article aims to update alcohol-related fatal crash relative risk estimates, defined as the risk of dying in those crashes at different blood alcohol concentrations (BACs) relative to the risk of dying in a crash when sober (BAC = .00 g/dl), and to examine any change in risk that could have taken place between 2007 and 2013-2014. More specifically, we examine changes in risk among BAC = .00 g/dl drivers and among BAC > .00 g/ dl drivers. METHOD: We matched and merged crash data from the Fatality Analysis Reporting System (FARS) and exposure data from the National Roadside Survey (NRS). To the matched database we applied logistic regression to estimate the changes in relative risk. RESULTS: We found that among sober (BAC = .00 g/dl) drivers, the risk of dying in a fatal crash decreased between 2007 and 2013-2014. For drinking drivers, however, no parallel reduction in the overall contribution of alcohol to the fatal crash risk occurred. Compared with 2007, in 2013-2014 the oldest group of drivers (age ≥ 35 years) were at an elevated crash risk when driving at low BACs (.00 g/dl < BAC < .02 g/dl). CONCLUSIONS: Although the decrease in crash risk for drivers with a BAC of .00 g/dl is encouraging, the consistency of the alcohol-related risk estimates over the last two decades suggests the need to substantially strengthen current efforts to abate drinking and driving.

Methods for investigating crash risk: Comparing case-control with responsibility analysis.

OBJECTIVE: There are 2 primary methods for establishing relative risk: case-control studies, in which crash and matched control data are collected separately, and responsibility analysis, which exploits a single existing crash database by using nonresponsible drivers as an "induced exposure" control group (which is less expensive and therefore more feasible for examining the large number of substances that can impact driving behavior). Though both approaches are scientifically sound and methodologically valid, each approach has its own inherent obstacles to overcome. In this article, we examine in detail how different criteria for the development of control cases influence the accuracy of crash risk estimates for drivers with positive blood alcohol concentrations (BACs). METHODS: We applied responsibility analysis to crash-involved drivers in a recent crash case-control study, thereby providing 2 sets of control cases: Those from responsibility analysis and those from the case control study. RESULTS: Case-control and responsibility analysis crash risk curves did not differ significantly, indicating that both systems generate valid estimates of the relative crash risk of drivers on the road. CONCLUSIONS: The results suggest that when researchers are faced with finance or time constraints that make case-control studies infeasible, responsibility analysis should be considered a viable alternate methodological approach.

Latent Classes of Polydrug Users as a Predictor of Crash Involvement and Alcohol Consumption.

OBJECTIVE: Polydrug users have been shown to be at higher risk for alcohol consumption and crash involvement. However, research has shown that polydrug groups differ in some important ways. It is currently unknown how polydrug-using groups differ in terms of crash involvement and alcohol consumption. METHOD: The current study used latent class analysis to examine subgroups of polydrug users (n = 384) among a sample of drivers in Virginia Beach, Virginia (N = 10,512). A series of logistic regression analyses were conducted to determine the relationship between polydrug use categories and crash involvement and alcohol consumption. RESULTS: Four distinct subclasses of users were identified among polydrug-using drivers: Class 1 is the "marijuana-amphetamines class" and accounts for 21.6% of polydrug users. Class 2 is the "benzo-antidepressant class" and accounts for 39.0% of polydrug users. Class 3 is the "opioid-benzo class" and accounts for 32.7% of polydrug users. Finally, Class 4 is the "marijuana-cocaine class" and accounts for 6.7% of the study sample. Drivers in the opioid-benzo class were significantly more likely than those in any other class as well as non-drug users and single-drug users to be involved in a crash and were more likely than those in most other conditions to consume alcohol. No significant difference was found between marijuana-amphetamine users or benzo-antidepressant users and non-drug users on crash risk. CONCLUSIONS: Some polydrug users are indeed at greater risk for crash involvement and alcohol consumption; however, not all polydrug users are significantly worse than single-drug users and/or non-drug users, and the practice of lumping polydrug users together when predicting crash risk runs the risk of inaccurately attributing crash involvement to certain drivers.

Association of State Alcohol Policies With Alcohol-Related Motor Vehicle Crash Fatalities Among US Adults.

Importance: Motor vehicle crashes are a leading cause of mortality. However, the association between the restrictiveness of the alcohol policy environment (ie, based on multiple existing policies) and alcohol-related crash fatalities has not been characterized previously to date. Objective: To examine the association between the restrictiveness of state alcohol policy environments and the likelihood of alcohol involvement among those dying in motor vehicle crashes in the United States. Design, Setting, and Participants: This investigation was a repeated cross-sectional study in which state alcohol policies (operationalized by the Alcohol Policy Scale [APS]) from 1999 to 2014 were related to motor vehicle crash fatalities from 2000 to 2015 using data from the Fatality Analysis Reporting System (1-year lag). Alternating logistic regression models and generalized estimating equations were used to account for clustering of multiple deaths within a crash and of multiple crashes occurring within states. The study also examined independent associations of mutually exclusive subgroups of policies, including consumption-oriented policies vs driving-oriented policies. The study setting was the 50 US states. Participants were 505 614 decedents aged at least 21 years from motor vehicle crashes from 2000 to 2015. Main Outcomes and Measures: Odds that a crash fatality was alcohol related (fatality stemmed from a crash in which ≥1 driver had a blood alcohol concentration [BAC] ≥0.08%). Results: From 2000 to 2015, there were 505 614 adult motor vehicle crash fatalities in the United States, of which 178 795 (35.4%) were alcohol related. Each 10-percentage point increase in the APS score (corresponding to more restrictive state policies) was associated with reduced individual-level odds of alcohol involvement in a crash fatality (adjusted odds ratio [aOR], 0.90; 95% CI, 0.89-0.91); results were consistent among most demographic and crash-type strata. More restrictive policies also had protective associations with alcohol involvement among crash fatalities associated with BACs from greater than 0.00% to less than 0.08%. After accounting for driving-oriented policies, consumption-oriented policies were independently protective for alcohol-related crash fatalities (aOR, 0.97; 95% CI, 0.96-0.98 based on a 10-percentage point increased APS score). Conclusions and Relevance: Strengthening alcohol policies, including those that do not specifically target impaired driving, could reduce alcohol-related crash fatalities. Policies may also protect against crash fatalities involving BAC levels below the current legal limit for driving in the United States.

Drivers with alcohol use disorders and their risks of crash involvement.

BACKGROUND: The relationship between driver blood alcohol concentration (BAC) and crash involvement is well understood. However, the role of alcohol use disorders (AUDs) (i.e., dependence or abuse) in crash occurrence, as distinguished from non-clinical heavy alcohol consumption, has not been adequately explored. METHODS: Data from the 2010-2011 Crash Risk Study conducted in Virginia Beach, VA, were used in this study. Drivers involved in crashes were compared with control drivers, and four drinker groups were examined: alcohol dependent, alcohol abusers, heavy drinkers, and all other current (i.e., normative) drinkers. Logistic regression analyses were conducted on two outcomes: having a moderate BAC (≥0.05 g/dl), and crash involvement. RESULTS: Overall, 2411 crash-involved and 5514 control drivers provided useable data, 52.4% of which were men and 70.8% Whites. The prevalence of drivers with AUDs was lower for the crash-involved drivers (8.7%) than for the control drivers (12.7%). Only heavy drinkers, but not abusive or dependent drinkers, were over four times more likely to drive with moderate BACs at nighttime. More important, at nighttime, the odds of crash involvement for dependent drinkers were only one third of those for normative drinkers. Daytime crashes, however, were more likely to involve normative drinkers than any of the other three drinker types. CONCLUSIONS: Drivers with AUDs are not more likely than normative drinkers to drive with moderate BACs at night. After accounting for the influence of BAC, dependent drinkers have a lower risk of being involved in a crash, at any time of the day.

Intercorrelation of Alcohol and Other Drug Use Disorders among a National Sample of Drivers.

This study examined the relationship between alcohol, marijuana, cocaine, and painkiller use disorders in a sample of drivers. We studied nighttime drivers aged 16 to 87 (n = 4,277) from the 2007 National Roadside Survey who reported substance use behaviors and provided breath tests for alcohol. Logistic regression analyses assessed the relationships between (1) substance (i.e., alcohol/marijuana/cocaine/pain killer) use disorders; (2) demographic characteristics; and (3) BAC levels. Overall, 13.2% of participants met criteria for marijuana use disorder, 7% met criteria for cocaine use disorder, and 15.4% met criteria for extra-medicinal painkiller use disorder. When self-report data were analyzed, three reciprocal associations emerged: (1) marijuana use disorders and alcohol use disorders were correlated; (2) marijuana use disorders and cocaine use disorders were correlated; and (3) cocaine use disorders and painkiller use disorders were correlated. BAC data revealed that marijuana and cocaine use disorders were both associated with positive BAC levels, but only cocaine use disorders were associated with BAC levels over the legal limit. Results suggest significant poly-substance use disorders in a sample of nighttime drivers, with variations by demographic characteristics. The individual and public health consequences of multiple substance use disorders among drivers are significant.

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

Marijuana and the Risk of Fatal Car Crashes: What Can We Learn from FARS and NRS Data?

Lab studies have shown that marijuana can severely impair driving skills. Epidemiological studies, however, have been inconclusive regarding the contribution of marijuana use to crash risk. In the United States, case-control studies based on the merging of comparable crash Fatality Analysis Reporting System (FARS) and non-crash National Roadside Survey (NRS) data have been applied to assess the contribution of drugs to crash risk, but these studies have yielded confusing, even contradictory results. We hypothesize that such a divergence of results emanates from limitations in the databases used in these studies, in particular that of the FARS. The goal of this effort is to examine this hypothesis, and in doing so, illuminate the pros and cons of using these databases for drugged-driving research efforts. We took advantage of two relatively recent cannabis crash risk studies that, despite using similar databases (the FARS and the NRS) and following similar overall approaches, yielded opposite results (Li, Brady, & Chen, 2013; Romano, Torres-Saavedra, Voas, & Lacey, 2014). By identifying methodological similarities and differences between these efforts, we assessed how the limitations of the FARS and NRS databases contributed to contradictory and biased results. Because of its limitations, we suggest that the FARS database should neither be used to examine trends in drug use nor to obtain precise risk estimates. However, under certain conditions (e.g., based on data from jurisdictions that routinely test for drugs, with as little variation in testing procedures as possible), the FARS database could be used to assess the contribution of drugs to fatal crash risk relative to other sources of risk such as alcohol.

Alcohol Policies and Alcohol-Related Motor Vehicle Crash Fatalities Among Young People in the US.

BACKGROUND: Motor vehicle crashes (MVCs) are a leading cause of death among young people in the United States. We examined the relationship between states' alcohol policy environments and alcohol-related MVC fatalities among children, adolescents, and young adults under the minimum legal drinking age of 21 years. METHODS: We used the Alcohol Policy Scale (APS), an assessment of 29 alcohol policies across 50 states and Washington, DC, developed with the assistance of an interdisciplinary Delphi panel. Using the Fatality Analysis Reporting System, we examined APS scores in relation to fatalities of people ≤20 years old from 2000 to 2013 occurring in crashes in which ≥1 involved driver had a blood alcohol content ≥0.08%. Logistic regression was used with a 1-year lag between policies and MVC fatalities and adjusted for potential confounders. RESULTS: Of 84 756 MVC fatalities of those ≤20 years old during the study period, 23 757 (28.0%) were alcohol related, including deaths of 11 006 (46.3%) drivers, 10 212 (43.0%) passengers, and 2539 (10.7%) pedestrians, cyclists, and others. People killed in alcohol-related MVCs were predominantly male (72.7%) and older (65.5% were 18-20 years old), and 51.2% were non-Hispanic white. Restrictive policy environments were associated with fewer fatalities (adjusted odds ratio, 0.91 per 10-percentage-point increase in APS score; 95% confidence interval, 0.89-0.94). The association was observed for drivers and passengers, male and female decendents, and children, adolescents, and young adults. CONCLUSIONS: More restrictive alcohol policies are associated with reduced alcohol-related MVC mortality among young people. Studies should scrutinize the relationship between policies and fatalities to highlight mechanisms.

Social Drinking Groups and Risk Experience in Nightclubs: Latent Class Analysis.

Nightclubs are a setting in which young adults purposefully seek out experiences, such as drug use and alcohol intoxication that can expose them to physical harm. While physical harm occurs fairly frequently within clubs, many patrons have safe clubbing experiences. Further, not all patrons experience potential harms the same way, as there are differences in aggression and intoxication. In this article we draw on data from a research study in which we sought to better understand the role of social drinking groups in experiences of risk within nightclubs, as the majority of patrons attend with others. We collected data from 1,642 patrons comprising 615 social drinking groups as they entered and exited nightclubs in a major U.S. city. We focused on six experiences that might cause physical harm: alcohol impairment, alcohol intoxication, drug use, physical aggression, sexual aggression, and impaired driving. We aggregated patron responses across social groups and used latent class statistical analysis to determine if and how experiences tended to co-occur within groups. This analysis indicated there were five distinct classes which we named Limited Vulnerability, Aggression Vulnerability, Substance Users, Impaired Drivers and Multi-Issue. We assessed the groups within each class for distinctions on characteristics and group context. We found differences in the groups in each class, such as groups containing romantic dyads experienced less risk, while those groups with greater familiarity, greater concern for safety, and higher expectations for consumption experienced more risk. Group composition has an impact on the experiences within a club on a given night, in particular when it comes to risk and safety assessment.