The Utility of Including the Strengths of Underage Drinking Laws in Determining Their Effect on Outcomes

Modeling of drinking and driving behaviors among adolescents and young adults in the United States: Complexities and Intervention outcomes

Alcohol-impaired driving is a formidable public health problem in the United States, claiming the lives of 37 individuals daily in alcohol-related crashes. Alcohol-impaired driving is affected by a multitude of interconnected factors, coupled with long delays between stakeholders' actions and their impacts, which not only complicate policy-making but also increase the likelihood of unintended consequences. We developed a system dynamics simulation model of drinking and driving behaviors among adolescents and young adults. This was achieved through group model building sessions with a team of multidisciplinary subject matter experts, and a focused literature review. The model was calibrated with data series from multiple sources and replicated the historical trends for male and female individuals aged 15 to 24 from 1982 to 2020. We simulated the model under different scenarios to examine the impact of a wide range of interventions on alcohol-related crash fatalities. We found that interventions vary in terms of their effectiveness in reducing alcohol-related crash fatalities. In addition, although some interventions reduce alcohol-related crash fatalities, some may increase the number of drinkers who drive after drinking. Based on insights from simulation experiments, we combined three interventions and found that the combined strategy may reduce alcohol-related crash fatalities significantly without increasing the number of alcohol-impaired drivers on US roads. Nevertheless, related fatalities plateau over time despite the combined interventions, underscoring the need for new interventions for a sustained decline in alcohol-related crash deaths beyond a few decades. Finally, through model calibration we estimated time delays between actions and their consequences in the system which provide insights for policymakers and activists when designing strategies to reduce alcohol-related crash fatalities.

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.

What determines the success of states in reducing alcohol related crash fatalities? A longitudinal analysis of alcohol related crashes in the U.S. from 1985 to 2019

In the United States, nearly 28 people die in alcohol-related motor vehicle crashes every day (1 fatality every 52 min). Over decades, states have enacted multiple laws to reduce such fatalities. From 1982 to 2019, the proportion of drivers in fatal crashes with a blood alcohol concentration (BAC) above 0.01 g/dl declined from 41% to 22%. States vary in terms of their success in reducing alcohol-related crash fatalities. The purpose of this study was to examine factors associated with changes in fatalities related to alcohol-impaired driving at the state level. We created a panel dataset of 50 states from 1985 to 2019 by merging different data sources and used fixed-effect linear regression models to analyze the data. Our two outcome variables were the ratio of drivers in fatal crashes with BAC ≥ 0.01 g/dl to those with BAC = 0.00, and the ratio of those with BAC ≥ 0.08 g/dl to those with BAC < 0.08 g/dl. Our independent variables included four laws (0.08 g/dl BAC per se law, administrative license revocation law, minimum legal drinking age law, and zero tolerance law), number of arrests due to impaired driving, alcohol consumption per capita, unemployment rate, and vehicle miles traveled. We found that the 0.08 g/dl per se law was significantly associated with lower alcohol-related crash fatalities while alcohol consumption per capita was significantly and positively associated with crash-related fatalities. Arrests due to driving under the influence (DUI) and crash fatalities were nonlinearly correlated. In addition, interaction of DUI arrests and two laws (0.08 g/dl BAC per se law, and zero tolerance) were significantly associated with lower crash-related fatalities. Our findings suggest that states which have more restrictive laws and enforce them are more likely to significantly reduce alcohol-related crash fatalities.

Association between a delay in driving licensure and driving while impaired and riding with an impaired driver among emerging adults

BACKGROUND

Teens who delay driving licensure may not be subject to graduated driver licensing restrictions that are known to reduce crash risk. We explored the association of delay in licensure with driving while impaired (DWI) and riding with an impaired driver (RWI) among emerging adults.

METHODS

Data from the NEXT Generation Health Study, starting with 10th grade (2009-2010), were analyzed. The outcome variables were Wave 7 (W7) self-reported DWI and RWI as dichotomous variables. The independent variable was delay in licensure. Covariates included sex, urbanicity, race/ethnicity, family structure, parent education, family affluence, teen's highest education, minimum legal drinking age laws, and onset age of alcohol use. Descriptive analysis and logistic regressions were conducted.

RESULTS

Of 2525 participants eligible for licensure, 887 reported a delay in licensure by 1-2 years (38.9%, weighted) and 1078 by > 2 years (30.3% weighted) across 7 waves. In W7, 23.5% (weighted and hereafter, 5.6% once, 17.8% ≥twice) of participants reported DWI and 32.42% (5.6% once, 25.4% ≥twice) reported RWI. Logistic regressions showed no overall significant association of delay in licensure with either W7 RWI or W7 DWI. However, in stratified analyses, among African American youth, delay in licensure was positively associated with DWI (OR = 2.41, p = 0.03) and RWI (OR = 2.72, p = 0.05). Among those with ≤ high school or lower education by W7, delayed licensure was positively associated with RWI (OR = 2.51, p < 0.01).

CONCLUSIONS

While in the overall sample, delayed licensure did not appear to be associated with DWI or RWI, our findings suggest that delayed licensure may be of concern to teen risk of DWI and RWI among African Americans and among those with lower educational attainment. Furthermore, as two-thirds of youth delayed licensure, more research is needed to determine whether this is more of a positive (i.e., protective) factor by reducing their exposure to crash risk or a negative (i.e., risk) factor due to their missing important driver safety stages of graduated driver licensing.

State alcohol policies, taxes, and availability as predictors of adolescent binge drinking trajectories into early adulthood

BACKGROUND AND AIMS

A number of alcohol policies in the United States have been presumed to reduce underage youth drinking. This study characterized underage youth binge-drinking trajectories into early adulthood and tested associations with the strength of the alcohol policy environment, beer excise taxes and number of liquor stores.

DESIGN

Longitudinal cohort study.

SETTING

United States.

PARTICIPANTS

A national cohort of 10th graders in 2010 (n = 2753), assessed annually from 2010 to 2015.

MEASUREMENTS

Participants reported on their 30-day binge drinking [defined as consuming five or more+ (for boys) or four or more (for girls) drinks within 2 hours]. We scored the strength of 19 state-level policies at baseline and summarized them into an overall score and two subdomain scores. We also assessed state beer excise taxes (dollars/gallon) and linked the number of liquor stores in 1 km to the participants' geocoded address.

FINDINGS

We identified five binge-drinking trajectories: low-risk (32.9%), escalating (26.1%), late-onset (13.8%), chronic (15.1%) and decreasing (12.0%). Lower overall alcohol policy strength was associated with increased risk of being in the escalating versus low-risk binge-drinking class [relative risk ratio (RRR) = 1.44 per 1 standard deviation (SD) in policy score; 95% confidence interval (CI) = 1.17, 1.77)]. Higher beer excise taxes were associated with a reduced risk of being in the escalating class (RRR = 0.22 per 1-dollar increase; 95% CI = 0.09, 0.50). The number of liquor stores was not significantly associated with any binge-drinking trajectory.

CONCLUSIONS

In the United States, stronger state alcohol policies and higher beer excise taxes appear to be associated with lower risk of escalating alcohol consumption trajectories among underage youth.

Assessing Campus Alcohol Policies: Measuring Accessibility, Clarity, and Effectiveness

BACKGROUND

Excessive alcohol consumption poses significant hazards to health and safety on college campuses. While substantial research exists regarding effective policies for preventing alcohol-related problems in the communities surrounding campuses, on-campus alcohol policies have received far less attention.

METHODS

Official campus alcohol policies (CAPs) were retrieved from the websites of the 15 member schools of the Maryland Collaborative to Reduce College Drinking and Related Problems, a voluntary statewide collaborative. CAPs were assessed for accessibility, clarity, and effectiveness. In addition to assessing whether campuses were in compliance with federal regulations for comprehensiveness of policies, a measure of likely policy effectiveness was developed through the use of 2 Delphi panels drawing on alcohol policy researchers and on-campus and community practitioners, respectively. The panels rated 35 potential policies and 13 possible sanctions; lists of policies and sanctions were compiled primarily from what was already in existence at 1 or more member schools.

RESULTS

For most campuses, the CAPs could be located within 30 seconds, but tended to be spread across multiple web pages. Language used to communicate the policies tended to be complex and above the reading level of someone with a high school education. At least half of the schools had less than half of the possible policies rated most or somewhat effective by the Delphi panels. Schools were more likely to employ the most effective sanctions, but somewhat and ineffective sanctions were also not uncommon.

CONCLUSIONS

CAPs are an important element in reducing negative consequences of alcohol consumption on college campuses. A higher level of research scrutiny is warranted to understand the extent to which CAPs are associated with excessive drinking, but this research describes an evidence- and expert-informed assessment approach that colleges can use to regularly analyze and update their CAPS.

How Strong is the "Fake ID Effect?" An Examination Using Propensity Score Matching in Two Samples

BACKGROUND

Underage college students who obtain and use false identification (fake ID) are at risk for negative outcomes. However, it is currently unclear how uniquely the fake ID itself serves as a vehicle to subsequent harm (i.e., the "fake ID effect") over and above general and trait-related risk factors (e.g., deviant peers, low self-control).

METHODS

To investigate whether the "fake ID effect" would hold after accounting for phenotypic risk, we utilized propensity score matching (PSM) in a cross-sectional sample of 1,454 students, and a longitudinal replication sample of 3,720 undergraduates. Individuals with a fake ID were matched with individuals without a fake ID, in terms of a number of trait-based and social risk factors. These matched groups were then compared on 5 problematic outcomes (i.e., frequent binge drinking, alcohol-related problems, arrests, marijuana use, and hard drug use).

RESULTS

Findings showed that "fake ID effects" were substantially-although not fully-diminished following PSM. The "fake ID effect" remained strongest for alcohol-related arrests. This may relate to issues of enforcement and students' willingness to engage in deviant behavior with a fake ID, or it may be a function of combined processes.

CONCLUSIONS

Overall, the findings suggest that interventions should not only be aimed at reducing the fake ID-related alcohol access specifically, but should also be aimed more generally toward at-risk youths' access to alcohol. Future research might examine whether fake IDs have their strongest potency as moderators of the effects of risky traits-such as impulsiveness-on drinking outcomes.