Do Brief Alcohol Interventions Reduce Driving After Drinking Among College Students? A Two-step Meta-analysis of Individual Participant Data

Young adult impaired driving behaviors and perceived norms of driving under the influence of simultaneous alcohol and cannabis use

BACKGROUND

Impaired driving behaviors among young adults who are under the influence of simultaneous alcohol and marijuana/cannabis (SAM) use are associated with increased risks of motor vehicle accidents and resulting increased injury and mortality. Exploration of associations with descriptive and injunctive norms may have prevention implications.

METHODS

Young adults (aged 18-25; N = 1941) in the 2019 cohort of the Washington Young Adult Health Survey comprised study participants. Associations between descriptive norms (estimates of other's frequency of driving under the influence of SAM [DUI-SAM] and riding with a SAM impaired driver [RWI-SAM]), injunctive norms (perceived approval or disapproval of DUI-SAM and RWI-SAM for young adults in their community), and past month DUI and RWI behaviors were assessed with logistic regression models, adjusting for covariates and applying post-stratification weights.

RESULTS

DUI-SAM was reported by 2.7% and almost double (5.3%) reported RWI-SAM at least once in the past month. Almost half of the participants believed the average young adults in Washington State engaged in DUI-SAM (49.8%) and RWI-SAM (48.7%) at least once a month in the past year (i.e., descriptive norms). The majority reported DUI-SAM (68.8%) and RWI-SAM (67.6%) to be totally unacceptable for young adults in their community (i.e., injunctive norms). In models adjusting for covariates including SAM use frequency and corresponding injunctive norms, descriptive norms were not associated with DUI, but were positively associated with RWI-SAM. However, after controlling for SAM use frequency and descriptive norms, higher perceived approval (i.e., injunctive norms) was significantly associated with increased odds of all DUI and RWI behaviors.

CONCLUSIONS

Injunctive norms for SAM impaired driving behaviors may be a promising intervention focus for DUI and RWI behaviors. Future research is needed to replicate these findings to determine if development and evaluation of individual and community-based interventions focused on changing normative beliefs are warranted.

Using mobile technology to influence alcohol-impaired driving risk perceptions and decisions

OBJECTIVE

Despite significant individual and societal risk, alcohol-impaired driving (AID) remains prevalent in the United States. Our aim was to determine whether breathalyzer-cued warning messages administered via mobile devices in the natural drinking environment could influence real-world AID cognitions and behaviors.

METHOD

One hundred twenty young adults (53% women; mean age = 24.7) completed 6 weeks of ecological momentary assessment (EMA) and provided breathalyzer samples using a BACtrack Mobile Pro linked to their mobile device. On mornings after drinking episodes, participants reported their driving activities from the previous evening (787 episodes). Participants were randomly assigned to receive warning messages if they reached a breath alcohol concentration (BrAC) ≥ .05, or no messages. Participants in the warnings condition reported their willingness to drive and perceived danger of driving at EMA prompts (1,541 reports).

RESULTS

We observed a significant effect of condition, such that the association between cumulative AID engagement and driving after reaching a BrAC of .05 was dampened among individuals in the warnings condition, compared to those in the no warnings condition. Receiving a warning message was associated with increased momentary perceived danger of driving and decreased willingness to drive.

CONCLUSIONS

We found that BrAC-cued warning messages reduced the probability of AID and willingness to drive while impaired, and increased the perceived danger of driving after drinking. These results serve as proof-of-concept for the use of mobile technology to deliver an adaptive just-in-time intervention to reduce the probability of AID. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The selection of statistical models for reporting count outcomes and intervention effects in brief alcohol intervention trials: A review and recommendations

Understanding the efficacy and relative effectiveness of a brief alcohol intervention (BAI) relies on obtaining a credible intervention effect estimate. Outcomes in BAI trials are often count variables, such as the number of drinks consumed, which may be overdispersed (i.e., greater variability than expected based on a given model) and zero-inflated (i.e., greater probability of zeros than expected based on a given model). Ignoring such distribution characteristics can lead to biased estimates and invalid statistical conclusions. In this critical review, we identified and reviewed 64 articles that reported count outcomes from a systematic review of BAI trials for adolescents and young adults from 2013 to 2018. Given many statistical models to choose from when analyzing count outcomes, we reviewed the models used and reporting practices in the BAI trial literature. A majority (61.3%) of analyses with count outcomes used linear models despite violations of normality assumptions; 75.6% of outcome variables demonstrated clear overdispersion. We provide an overview of available count models (Poisson, negative binomial, zero-inflated or hurdle, and marginalized zero-inflated Poisson regression) and formulate practical guidelines for reporting outcomes of BAIs. We provide a visual step-by-step decision guide for selecting appropriate statistical models and reporting results for count outcomes. We list accessible resources to help researchers select an appropriate model with which to analyze their data. Recent advances in count distribution-based models hold promise for evaluating count outcomes to gauge the efficacy and effectiveness of BAIs and identify critical covariates in alcohol epidemiologic research. We recommend that researchers report the distributional properties of count outcomes, such as the proportion of zero counts, and select an appropriate statistical analysis for count outcomes using the provided decision tree. By following these recommendations, future research may yield more accurate, transparent, and reproducible results.

Brief Alcohol Interventions are Effective through 6 Months: Findings from Marginalized Zero-inflated Poisson and Negative Binomial Models in a Two-step IPD Meta-analysis

To evaluate and optimize brief alcohol interventions (BAIs), it is critical to have a credible overall effect size estimate as a benchmark. Estimating such an effect size has been challenging because alcohol outcomes often represent responses from a mixture of individuals: those at high risk for alcohol misuse, occasional nondrinkers, and abstainers. Moreover, some BAIs exclusively focus on heavy drinkers, whereas others take a universal prevention approach. Depending on sample characteristics, the outcome distribution might have many zeros or very few zeros and overdispersion; consequently, the most appropriate statistical model may differ across studies. We synthesized individual participant data (IPD) from 19 studies in Project INTEGRATE (Mun et al., 2015b) that randomly allocated participants to intervention and control groups (N = 7,704 participants, 38.4% men, 74.7% White, 58.5% first-year students). We sequentially estimated marginalized zero-inflated Poisson (Long et al., 2014) or negative binomial regression models to obtain covariate-adjusted, study-specific intervention effect estimates in the first step, which were subsequently combined in a random-effects meta-analysis model in the second step. BAIs produced a statistically significant 8% advantage in the mean number of drinks at both 1-3 months (RR = 0.92, 95% CI = [0.85, 0.98]) and 6 months (RR = 0.92, 95% CI = [0.85, 0.99]) compared to controls. At 9-12 months, there was no statistically significant difference in the mean number of drinks between BAIs and controls. In conclusion, BAIs are effective at reducing the mean number of drinks through at least 6 months post intervention. IPD can play a critical role in deriving findings that could not be obtained in original individual studies or standard aggregate data meta-analyses.

Injunctive Norms and Driving Under the Influence and Riding With an Impaired Driver Among Young Adults in Washington State

PURPOSE

Alcohol- and cannabis-impaired driving behaviors remain a public health concern especially among young adults (i.e., ages 18-25). Limited updates to prevention efforts for these behaviors may be due, in part, to limited understanding of malleable psychosocial predictors. The current study assessed associations between perceived injunctive norms (i.e., acceptability) of driving under the influence of alcohol (DUI-A) and cannabis (DUI-C), and riding with a driver under the influence of alcohol (RWI-A) and cannabis (RWI-C) in Washington State young adults.

METHODS

Participants included 1,941 young adults from the 2019 cohort of the Washington Young Adult Health Survey. Weighted logistic regressions assessed the associations between peer injunctive norms and impaired driving-related behaviors.

RESULTS

A weighted total of 11.5% reported DUI-A, 12.4% DUI-C, 10.9% RWI-A, and 20.9% RWI-C at least once in the past 30 days. Overlap between the outcomes was observed, indicating some young adults had engaged in multiple impaired driving-related behaviors. After controlling for substance use frequency, weighted logistic regressions indicated more positive perceived injunctive norms were associated with nearly 2 ½ times higher odds of DUI-A, 8 times higher odds of DUI-C, 4 times higher odds of RWI-A and six and a half times higher odds of RWI-C.

DISCUSSION

Results increase the understanding of how injunctive norms-a potentially malleable psychosocial factor-are associated with four impaired driving-related outcomes. Prevention programs that focus on assessing and addressing the norms of these outcomes individually and collectively, such as normative feedback interventions and media campaigns, may be helpful in reducing these behaviors.

Investigating for Whom Brief Substance Use Interventions Are Most Effective: An Individual Participant Data Meta-analysis

Prior research suggests that brief interventions (BIs) for alcohol and other drug use may vary in effectiveness across patient sociodemographic factors. The objective of this individual participant data (IPD) meta-analysis was to explore for whom BIs delivered in general healthcare settings are more or less effective. We examined variability in BI effects by patient age, sex, employment, education, relationship status, and baseline severity of substance use using a two-stage IPD meta-analysis approach. All trials included in a parent aggregate data meta-analysis (k = 116) were invited to contribute IPD, and 29 trials provided patient-level data (12,074 participants). Among females, BIs led to significant reductions in binge alcohol consumption ([Formula: see text] = 0.09, 95% CI [0.03, 0.14]), frequency of alcohol consumption ([Formula: see text] = 0.10, 95% CI [0.03, 0.17]), and alcohol-related consequences ([Formula: see text] = 0.16, 95% CI [0.08, 0.25]), as well as greater substance use treatment utilization ([Formula: see text] = 0.25, 95% CI [0.21, 0.30]). BIs yielded larger reductions in frequency of alcohol consumption at 3-month follow-up for individuals with less than a high school level education ([Formula: see text] = 0.16, 95% CI [0.09, 0.22]). Given evidence demonstrating modest BI effects on alcohol use and mixed or null findings for BI effects on other drug use, BI research should continue to investigate potential drivers of effect magnitude and variation.  PROTOCOL REGISTRATION DETAILS: The protocol for this review was pre-registered in PROSPERO #CRD42018086832 and the analysis plan was pre-registered in OSF: osf.io/m48g6.

Do brief motivational interventions increase motivation for change in drinking among college students? A two-step meta-analysis of individual participant data

BACKGROUND

Brief motivational interventions (BMIs) are one of the most effective individually focused alcohol intervention strategies for college students. Despite the central theoretical role of motivation for change in BMIs, it is unclear whether BMIs increase motivation to change drinking behavior. We conducted a two-step meta-analysis of individual participant data (IPD) to examine whether BMIs increase motivation for change. N = 5903;59% women, 72% White) from Project INTEGRATE. The BMIs included individually delivered motivational interviewing with personalized feedback (MI + PF), stand-alone personalized feedback (PF), and group-based motivational interviewing (GMI).

METHODS

We included 15 trials of BMI (N = 5903;59% women, 72% White) from Project INTEGRATE. The BMIs included individually-delivered motivational interviewing with personalized feedback (MI + PF), stand-alone personalized feedback (PF), and group-based motivational interviewing (GMI). Different measures and responses used in the original trials were harmonized. Effect size estimates were derived from a model that adjusted for baseline motivation and demographic variables for each trial (step 1) and subsequently combined in a random-effects meta-analysis (step 2).

RESULTS

The overall intervention effect of BMIs on motivation for change was not statistically significant (standard mean difference [SMD]: 0.026, 95% CI: [-0.001, 0.053], p = 0.06, k = 19 comparisons). Of the three subtypes of BMIs, GMI, which tended to provide motivation-targeted content, had a statistically significant intervention effect on motivation, compared with controls (SMD: 0.055, 95% CI: [0.007, 0.103], p = 0.025, k = 5). By contrast, there was no evidence that MI + PF (SMD = 0.04, 95% CI: [-0.02, 0.10], k = 6, p = 0.20) nor PF increased motivation (SMD = 0.005, 95% CI: [-0.028, 0.039], k = 8, p = 0.75), compared with controls. Post hoc meta-regression analysis suggested that motivation sharply decreased each month within the first 3 months postintervention (b = -0.050, z = -2.80, p = 0.005 for k = 14).

CONCLUSIONS

Although BMIs provide motivational content and normative feedback and are assumed to motivate behavior change, the results do not wholly support the hypothesis that BMIs improve motivation for change. Changing motivation is difficult to assess during and following interventions, but it is still a theoretically important clinical endpoint. Further, the evidence cautiously suggests that changing motivation may be achievable, especially if motivation-targeted content components are provided.

Does abstaining from alcohol in high school moderate intervention effects for college students? Implications for tiered intervention strategies

Brief motivational intervention (BMI) and personalized feedback intervention (PFI) are individual-focused brief alcohol intervention approaches that have been proven efficacious for reducing alcohol use among college students and young adults. Although the efficacy of these two intervention approaches has been well established, little is known about the factors that may modify their effects on alcohol outcomes. In particular, high school drinking may be a risk factor for continued and heightened use of alcohol in college, and thus may influence the outcomes of BMI and PFI. The purpose of this study was to investigate whether high school drinking was associated with different intervention outcomes among students who received PFI compared to those who received BMI. We conducted moderation analyses examining 348 mandated students (60.1% male; 73.3% White; and 61.5% first-year student) who were randomly assigned to either a BMI or a PFI and whose alcohol consumption was assessed at 4-month and 15-month follow-ups. Results from marginalized zero-inflated Poisson models showed that high school drinking moderated the effects of PFI and BMI at the 4-month follow-up but not at the 15-month follow-up. Specifically, students who reported no drinking in their senior year of high school consumed a 49% higher mean number of drinks after receiving BMI than PFI at the 4-month follow-up. The results suggest that alcohol consumption in high school may be informative when screening and allocating students to appropriate alcohol interventions to meet their different needs.

A Structural Equation Modeling Approach to Meta-analytic Mediation Analysis Using Individual Participant Data: Testing Protective Behavioral Strategies as a Mediator of Brief Motivational Intervention Effects on Alcohol-Related Problems

This paper introduces a meta-analytic mediation analysis approach for individual participant data (IPD) from multiple studies. Mediation analysis evaluates whether the effectiveness of an intervention on health outcomes occurs because of change in a key behavior targeted by the intervention. However, individual trials are often statistically underpowered to test mediation hypotheses. Existing approaches for evaluating mediation in the meta-analytic context are limited by their reliance on aggregate data; thus, findings may be confounded with study-level differences unrelated to the pathway of interest. To overcome the limitations of existing meta-analytic mediation approaches, we used a one-stage estimation approach using structural equation modeling (SEM) to combine IPD from multiple studies for mediation analysis. This approach (1) accounts for the clustering of participants within studies, (2) accommodates missing data via multiple imputation, and (3) allows valid inferences about the indirect (i.e., mediated) effects via bootstrapped confidence intervals. We used data (N = 3691 from 10 studies) from Project INTEGRATE (Mun et al. Psychology of Addictive Behaviors, 29, 34–48, 2015) to illustrate the SEM approach to meta-analytic mediation analysis by testing whether improvements in the use of protective behavioral strategies mediate the effectiveness of brief motivational interventions for alcohol-related problems among college students. To facilitate the application of the methodology, we provide annotated computer code in R and data for replication. At a substantive level, stand-alone personalized feedback interventions reduced alcohol-related problems via greater use of protective behavioral strategies; however, the net-mediated effect across strategies was small in size, on average.