Effectiveness Of Brief Alcohol Intervention Research Articles

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.

Effectiveness of Brief Alcohol Intervention in Reducing Alcohol Consumption Among Patients With Alcohol-Related Facial Trauma in the Emergency Department: A Systematic Review and Meta-Analysis

Facial trauma is a frequent presentation to the emergency department following alcohol-related injuries. Brief alcohol intervention (BAI) is a form of a motivational interview which is implemented in the postinjury phase to educate patients on the detrimental effects of their alcohol drinking behavior and reduce their future consumption. This systematic review and meta-analysis aims to assess the impact of BAI on alcohol drinking behavior in the emergency department setting. An extensive systematic literature review was implemented from 21 October 2020 to 23 November 2020. All clinical studies that reported the outcomes of brief alcohol intervention on alcohol consumption in patients who attended the emergency department with facial injuries were included in the systematic review. The data sources utilized include Google Scholar, PubMed, ISI, Scopus, EMBASE, SIGLE, Virtual Health Library, NYAM, ClinicalTruaks.Gov, Controlled Trials (mRCT), and ICTRP. The current systematic review included 8 articles encompassing 941 patients. Of the included patients, 304 (32.3%) patients were subjected to BAI, while the remaining 637 (67.7%) were not subjected to BAI. BAI significantly decreased the amount of alcohol consumption 3months after intervention (SMD -0.596; 95% CI -1.067, -0.126; P=.013). Patients who received BAI were 1.89 times more likely to reduce their alcohol consumption (OR 1.89; 95% CI 0.59, 6.11; P=.29). BAI is an efficacious motivational tool for patients with facial trauma in the emergency setting. It can effectively reduce the amount and rate of alcohol consumption after facial trauma in the short-term. However, a higher level of evidence is required to reach long-term conclusions.

Effectiveness of brief alcohol interventions for pregnant women: a systematic literature review and meta-analysis

BackgroundPrenatal alcohol exposure (PAE) can result in a range of adverse neonatal outcomes, including Fetal Alcohol Spectrum Disorder (FASD). This systematic review and meta-analysis sought to investigate the effectiveness of brief interventions (BIs) in eliminating or reducing 1) alcohol consumption during pregnancy; and 2) PAE-related adverse neonatal outcomes; and 3) cost-effectiveness of BIs.MethodWe conducted a systematic literature search for original controlled studies (randomized control trials (RCTs); quasi-experimental) in any setting, published from 1987 to 2021. The comparison group was no/minimal intervention, where a measure of alcohol consumption was reported. Studies were critically appraised using the Centre for Evidence-based Medicine Oxford critical appraisal tool for RCTs (1). The certainty in the evidence for each outcome was assessed using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) (2). Meta-analysis of continuous and binary estimates of effect-size for similar outcome measures for BIs versus control groups were pooled and reported as mean difference (MD) Hedges’ g and odds ratios (ORs), respectively.ResultsIn total, 26 studies, all from high income countries, met inclusion criteria. Alcohol abstinence outcome available in 12 studies (n = 2620) found modest effects in favor of BIs conditions by increasing the odds of abstinence by 56% (OR = 1.56, 95% confidence interval (CI) = 1.15–2.13, I2 = 46.75%; p = 0.04). BIs effects for reduction in mean drinks/week (Cohen’s d = − 0.21, 95%CI = - 0.78 to 0.36; p = 0.08) and AUDIT scores (g = 0.10, 95%CI = − 0.06 to 0.26; p = 0.17) were not statistically significant. Among seven studies (n = 740) reporting neonatal outcomes, BI receipt was associated with a modest and significant reduction in preterm birth (OR = 0.67, 95% CI = 0.46–0.98, I2 = 0.00%; p = 0.58). No statistically significant differences were observed for mean birthweight or lower likelihood of low birth weight (LBW). Certainty in the evidence was rated as ‘low’. No eligible studies were found on cost-effectiveness of BIs.ConclusionBIs are moderately effective in increasing abstinence during pregnancy and preventing preterm birth. More studies on the effectiveness of BIs are needed from low- and middle-income countries, as well as with younger mothers and with a broader range of ethnic groups.

Brief Alcohol Interventions With Older Adults: Results of a Systematic Review of Literature

Older persons are especially vulnerable to the negative effects of alcohol misuse. National reports show that the older-adult population is the least likely group to perceive a need for treatment and be screened for alcohol-related problems. Little research has examined the impact of brief interventions on different drinking outcomes in at-risk older adults. To address this gap, the current study sought to systematically review empirical literature examining the effectiveness of brief alcohol interventions (BAI) implemented with adults (≥50) engaged in at-risk drinking. The authors developed specific a priori inclusion criteria (e.g., alcohol-related outcome measures, randomized controlled trials, RCT) before beginning the search process. Key terms were entered into 9 databases to yield an initial pool of 5,909 articles, from which 5,572 were excluded. A total of 337 articles remained, from which an additional 89 were excluded. Next, the authors independently reviewed 248 full-text, empirical articles and subsequently excluded 237 that did not satisfy inclusion criteria. Thus, the current systematic review yielded 11 studies representing RCT or experimental designs that employed random assignment. Findings of the review indicated that 7 (63.6%) studies showed a positive effect, with only 1 showing no positive effect of the intervention. For the remaining 3 (27.2%), the positive effect of the intervention was not conclusively determined due to study design issues. Overall findings suggest that BAI are effective in reducing alcohol consumption in the older-adult population. Additional evidence is needed to further knowledge consistent with recent initiatives (e.g., Age-Friendly Health Systems, 4Ms) that promote healthy aging.

Network Meta-Analysis Techniques for Synthesizing Prevention Science Evidence.

Network meta-analysis is a popular statistical technique for synthesizing evidence from studies comparing multiple interventions. Benefits of network meta-analysis, over more traditional pairwise meta-analysis approaches, include evaluating efficacy/safety of interventions within a single framework, increased precision, comparing pairs of interventions that have never been directly compared in a trial, and providing a hierarchy of interventions in terms of their effectiveness. Network meta-analysis is relatively underutilized in prevention science. This paper therefore presents a primer of network meta-analysis for prevention scientists who wish to apply this method or to critically appraise evidence from publications using the method. We introduce the key concepts and assumptions of network meta-analysis, namely, transitivity and consistency, and demonstrate their applicability to the field of prevention science. We then illustrate the method using a network meta-analysis examining the comparative effectiveness of brief alcohol interventions for preventing hazardous drinking among college students. We provide data and code for all examples. Finally, we discuss considerations that are particularly relevant in network meta-analyses in the field of prevention, such as including non-randomized evidence.

Brief alcohol interventions with older adults: a systematic review of literature

ABSTRACT The current systematic review analyzed empirical studies examining the effectiveness of brief alcohol interventions (BAI) for at-risk older adults. The authors independently reviewed the literature according to specific a priori criteria. Quantity and frequency of drinking, binge-drinking days, and drinking risks comprised the outcome measures. The current review yielded 11 studies representing randomized controlled trials or experimental designs that employed random assignment. Among reviewed studies, seven (63.6%) showed a positive effect with only one showing no positive effect of the intervention. For the remaining 3 (27.2%), the positive effect of the intervention was not conclusively determined due to study design issues. Findings, overall suggest that BAI are effective in reducing alcohol consumption in the older-adult population. Additional evidence is needed to further knowledge consistent with recent initiatives that promote healthy aging.

Meta-analysis with Robust Variance Estimation: Expanding the Range of Working Models.

In prevention science and related fields, large meta-analyses are common, and these analyses often involve dependent effect size estimates. Robust variance estimation (RVE) methods provide a way to include all dependent effect sizes in a single meta-regression model, even when the exact form of the dependence is unknown. RVE uses a working model of the dependence structure, but the two currently available working models are limited to each describing a single type of dependence. Drawing on flexible tools from multilevel and multivariate meta-analysis, this paper describes an expanded range of working models, along with accompanying estimation methods, which offer potential benefits in terms of better capturing the types of data structures that occur in practice and, under some circumstances, improving the efficiency of meta-regression estimates. We describe how the methods can be implemented using existing software (the "metafor" and "clubSandwich" packages for R), illustrate the proposed approach in a meta-analysis of randomized trials on the effects of brief alcohol interventions for adolescents and young adults, and report findings from a simulation study evaluating the performance of the new methods.

Effectiveness of Screening and Brief Alcohol Intervention at the Workplace: A Study Protocol for a Randomized Controlled Trial at Five Japan-Based Companies.

Despite evidence regarding the effectiveness of screening and brief interventions for excessive alcohol use in primary care, these tools are not a part of routine practice. It has been suggested that using these tools at the workplace may be critical to alcohol-associated harm; however, evidence for this claim is unclear. The aim of this article is to develop a study protocol which evaluates the effect of brief alcohol intervention at the workplace to reduce harmful alcohol drinking. A randomized controlled trial involving employees (aged 20-74 years) of five Japan-based companies who were screened "positive" by Alcohol Use Disorder Identification Test (AUDIT) is on-going. Participants were randomized into "Patient Information Leaflet" (control group), "Brief Advice and Counselling," and "Five-minute Brief Advice" groups. A self-administered questionnaire was used to assess alcohol consumption, lifestyle behavior, health status, work performance, and consequences of alcohol use. Data of laboratory markers were collected from routine health checkups. A total of 351 participants were randomized into Patient Information Leaflet (n = 111), Brief Advice and Counselling (n = 128), and Five-minute Brief Advice (n = 112) groups. Participants were mostly men with a median age of 49 years. Median AUDIT score and weekly alcohol consumption were 11 points and 238 g/week, respectively. Two-thirds of the participants were manufacturing workers. This study protocol developed the first trial in Japan to investigate the effect of brief alcohol intervention combined with a recommended screening tool at the workplace. Our findings can provide evidence on the effectiveness and relevance of these tools to occupational health.

Social network heavy drinking moderates the effects of a brief motivational intervention for alcohol use among injured patients

BackgroundLimited research has focused on identifying the extent to which social networks impact the effectiveness of brief alcohol interventions delivered in trauma care settings. ObjectivesThe research presented here examines the extent to which the percent of heavy drinkers and percent of abstainers in one’s social network moderates the effectiveness of a brief motivational intervention with and without a telephone booster on alcohol use among trauma patients. MethodSecondary data analyses were conducted using data from 596 participants (456males) who were recruited from three urban Level I trauma centers. Patients were randomized to one of the three intervention conditions: brief advice (BA; n = 200), brief motivational intervention (BMI; n = 203), and BMI with a telephone booster (BMI + B; n = 193). For the purpose of the present study, measures of alcohol-specific social network characteristics at baseline and alcohol use at 3- and 6-month follow-up were used. ResultsAt low percentages (0% to ~7%) of people in one’s social network who are heavy drinkers, there was a negative, statistically significant effect of the BMI conditions versus the BA condition on alcohol use. However, percent of abstainers did not moderate the effects of the BMI conditions. ConclusionThe results suggest that the BMI and BMI + B conditions may be most effective among patients with no heavy drinkers in their social networks. BMIs may benefit from including a component that addresses having one or more heavy drinkers in one’s social network.

Meta-analytic approaches for examining complexity and heterogeneity in studies of adolescent development

IntroductionIn the field of adolescent development, meta-analysis offers valuable tools for synthesizing and assessing cumulative research evidence on the effectiveness of programs, practices, and policies intended to promote healthy adolescent development. When examining the impact of a program implemented across multiple primary studies, variation is often observed in the methodological attributes of those primary studies, such as their implementation methods, program components, participant characteristics, outcome measurement, and the systems in which programs are deployed. Differences in methodological attributes of primary studies represented in a meta-analysis, referred to as complexity, can yield variation in true effects across primary studies, which is described as heterogeneity. MethodsWe discuss heterogeneity as a parameter of interest in meta-analysis, introducing and demonstrating both graphical and statistical methods for evaluating the magnitude and impact of heterogeneity. We discuss approaches for presenting characteristics of heterogeneity in meta-analytic findings, and methods for identifying and statistically controlling for aspects of methodological complexity that may contribute to variation in effects across primary studies. ResultsTopics and methods related to assessing and explaining heterogeneity were contextualized in the field of adolescent development using a sample of primary studies from a large meta-analysis examining the effectiveness of brief alcohol interventions for youth. We highlighted approaches currently underutilized in the field and provided R code for key methods to broaden their use. ConclusionsBy discussing various heterogeneity statistics, visualizations, and explanatory methods, this article provides the applied developmental researcher a foundational understanding of complexity and heterogeneity in meta-analysis.

Effectiveness of brief alcohol interventions in primary care populations.

Effectiveness of brief alcohol interventions in primary care populations.

Back to basics.

Commentary to: Reviewing and interpreting the effects of brief alcohol interventions: comment on a Cochrane review about motivational interviewing for young adults

Is it time to define minimally clinically important differences for patient-reported outcome measures used in alcohol brief intervention studies?

Commentary to: Reviewing and interpreting the effects of brief alcohol interventions: comment on a Cochrane review about motivational interviewing for young adults

A meta-analysis of brief alcohol interventions for adolescents and young adults: variability in effects across alcohol measures

ABSTRACTBackground: Brief alcohol interventions are one approach for reducing drinking among youth, but may vary in effectiveness depending on the type of alcohol assessments used to measure effects. Objectives: To conduct a meta-analysis that examined the effectiveness of brief alcohol interventions for adolescents and young adults, with particular emphasis on exploring variability in effects across outcome measurement characteristics. Method: Eligible studies were those using an experimental or quasi-experimental design to examine the effects of a brief alcohol intervention on a post-intervention alcohol use measure for youth aged 11–30. A comprehensive literature review identified 190 unique samples that were included in the meta-analysis. Taking a Bayesian approach, we used random-effects multilevel models to estimate the average effect and model variability across outcome measurement types. Results: Brief alcohol interventions led to significant reductions in self-reported alcohol use among adolescents ( = 0.25, 95% credible interval [CrI 0.13, 0.37]) and young adults ( = 0.15, 95% CrI [0.12, 0.18]). These results were consistent across outcomes with varying reference periods, but varied across outcome construct type and assessment instruments. Among adolescents, effects were larger when measured using the Timeline Followback; among young adults, effects were smaller when measured using the Alcohol Use Disorders Identification Test. Conclusion: The strength of the beneficial effects of brief alcohol interventions on youth’s alcohol use may vary depending upon the outcome measure utilized. Nevertheless, significant effects were observed across measures. Although effects were modest in size, they were clinically significant and show promise for interrupting problematic alcohol use trajectories among youth.

Reviewing and interpreting the effects of brief alcohol interventions: comment on a Cochrane review about motivational interviewing for young adults.

BackgroundCochrane recently published a systematic review on motivational interviewing (MI) for alcohol misuse in young adults. The review authors concluded that ‘there are no substantive, meaningful benefits of MI interventions for the prevention of alcohol misuse’ (p. 2), as effect sizes were ‘small and unlikely to be of any meaningful benefit in practice’ (p. 27). As most of these interventions were quite brief, we wish to open a dialogue about interpreting effect sizes in this review and of (brief) alcohol interventions more generally.AnalysisWe analyze four methodological aspects of the review that likely influenced the author's conclusions about intervention effects: (1) risk of bias assessments, (2) search strategies, (3) assessing the quality of the body of evidence and (4) definitions of sustainability and clinical significance.ConclusionsWe interpret the effect sizes found in this review to indicate modest yet beneficial and potentially meaningful effects of these interventions, given their brevity and low cost. This interpretation is consistent with other reviews on brief, MI‐based interventions and brief interventions more generally. We therefore encourage the field to re‐open dialogue about the clinical importance of the effects of MI on alcohol misuse by young adults. Rather than dismissing interventions with small effects, we believe a more fruitful way forward for the field would be to catalogue effect sizes for various alcohol interventions. Such a catalogue would help stakeholders themselves to choose which interventions meet their minimum desired impact, and thus may be suitable given their targeted populations, setting and resources.

Brief Intervention Decreases Drinking Frequency in HIV-Infected, Heavy Drinking Women: Results of a Randomized Controlled Trial.

Hazardous alcohol use by HIV-infected women is associated with poor HIV outcomes and HIV transmission risk behaviors. We examined the effectiveness of brief alcohol intervention (BI) among hazardous drinking women receiving care in an urban HIV clinic. Women were randomized to a 2-session BI or usual care. Outcomes assessed at baseline, 3, 6, and 12 months included 90-day frequency of any alcohol use and heavy/binge drinking (≥4 drinks per occasion), and average drinks per drinking episode. Secondary outcomes included HIV medication and appointment adherence, HIV-1 RNA suppression, and days of unprotected vaginal sex. We examined intervention effectiveness using generalized mixed-effect models and quantile regression. Of 148 eligible women, 74 were randomized to each arm. In mixed-effects models, 90-day drinking frequency decreased among intervention group compared with control, with women in the intervention condition less likely to have a drinking day (odds ratio: 0.42; 95% confidence interval: 0.23 to 0.75). Heavy/binge drinking days and drinks per drinking day did not differ significantly between groups. Quantile regression demonstrated a decrease in drinking frequency in the middle to upper ranges of the distribution of drinking days and heavy/binge drinking days that differed significantly between intervention and control conditions. At follow-up, the intervention group had significantly fewer episodes of unprotected vaginal sex. No intervention effects were observed for other outcomes. BI reduces frequency of alcohol use and unprotected vaginal sex among HIV-infected women. More intensive services may be needed to lower drinks per drinking day and enhance care for more severely affected drinkers.

The effectiveness of brief alcohol interventions delivered by community pharmacists: randomized controlled trial.

To undertake the first randomized controlled trial to evaluate the effectiveness of a brief intervention delivered by community pharmacists to reduce hazardous or harmful drinking. This parallel group randomized trial allocated participants individually to brief alcohol intervention (n = 205) or a leaflet-only control condition (n = 202), with follow-up study after 3 months. Sixteen community pharmacies in one London Borough, UK. A total of 407 pharmacy customers (aged 18 years or over) with Alcohol Use Disorder Identification Test (AUDIT) scores 8-19, inclusive. A brief motivational discussion of approximately 10 minutes' duration, for which 17 pharmacists received a half-day of training. Hazardous or harmful drinking was assessed using the AUDIT administered by telephone by a researcher blind to allocation status. The two primary outcomes were: (1) change in AUDIT total scores and (2) the proportions no longer hazardous or harmful drinkers (scoring < 8) at 3 months. The four secondary outcomes were: the three subscale scores of the AUDIT (for consumption, problems and dependence) and health status according to the EQ-5D (a standardized instrument for use as a measure of health outcome). At 3 months 326 (80% overall; 82% intervention, 78% control) participants were followed-up. The difference in reduction in total AUDIT score (intervention minus control) was -0.57, 95% confidence interval (CI) = -1.59 to 0.45, P = 0.28. The odds ratio for AUDIT ˂ 8 (control as reference) was 0.87, 95% CI = 0.50 to 1.51, P = 0.61). For two of the four secondary outcomes (dependence score: -0.46, 95% CI = -0.82 to -0.09, P = 0.014; health status score: -0.09, 95% CI = -0.16 to -0.02, P = 0.013) the control group did better, and in the other two there were no differences (consumption score: -0.05, 95% CI = -0.54 to 0.44, P = 0.85; non-dependence problems score: -0.13, 95% CI = -0.66 to 0.41). Sensitivity analyses did not change these findings. A brief intervention delivered by community pharmacists appears to have had no effect in reducing hazardous or harmful alcohol consumption.

Specialty substance use disorder services following brief alcohol intervention: a meta-analysis of randomized controlled trials.

Brief alcohol interventions in medical settings are efficacious in improving self-reported alcohol consumption among those with low-severity alcohol problems. Screening, Brief Intervention and Referral to Treatment initiatives presume that brief interventions are efficacious in linking patients to higher levels of care, but pertinent evidence has not been evaluated. We estimated main and subgroup effects of brief alcohol interventions, regardless of their inclusion of a referral-specific component, in increasing the utilization of alcohol-related care. A systematic review of English language papers published in electronic databases to 2013. We included randomized controlled trials (RCTs) of brief alcohol interventions in general health-care settings with adult and adolescent samples. We excluded studies that lacked alcohol services utilization data. Extractions of study characteristics and outcomes were standardized and conducted independently. The primary outcome was post-treatment alcohol services utilization assessed by self-report or administrative data, which we compared across intervention and control groups. Thirteen RCTs met inclusion criteria and nine were meta-analyzed (n = 993 and n = 937 intervention and control group participants, respectively). In our main analyses the pooled risk ratio (RR) was = 1.08, 95% confidence interval (CI) = 0.92-1.28. Five studies compared referral-specific interventions with a control condition without such interventions (pooled RR = 1.08, 95% CI = 0.81-1.43). Other subgroup analyses of studies with common characteristics (e.g. age, setting, severity, risk of bias) yielded non-statistically significant results. There is a lack of evidence that brief alcohol interventions have any efficacy for increasing the receipt of alcohol-related services.

Can brief alcohol interventions for youth also address concurrent illicit drug use? results from a meta-analysis.

Brief interventions aimed at reducing alcohol use among youth may interrupt a possible developmental progression to more serious substance use if they can also affect the use of other illicit drugs. This meta-analysis examined the findings of recent research on the effects of brief alcohol interventions for adolescents and young adults on both alcohol and illicit drug use. Eligible studies were those using randomized or controlled quasi-experimental designs to examine the effects of brief alcohol interventions on illicit drug use outcomes among youth. A comprehensive literature search identified 30 eligible study samples that, on average, included participants age 17, with 57% male participants and 56% White youth. Three-level random-effects meta-analyses were used to estimate mean effect sizes and explore variability in effects. Overall, brief interventions targeting both alcohol and other drugs were effective in reducing both of these substances. However, the brief interventions that targeted only alcohol had no significant secondary effects on untargeted illicit drug use. The evidence from current research, therefore, shows modest beneficial effects on outcomes that are targeted by brief interventions for youth, but does not show that those effects generalize to untargeted illicit drug use outcomes.

Effects of Brief Alcohol Interventions on Drinking and Driving among Youth: A Systematic Review and Meta-analysis.

Alcohol-impaired driving persists as a major cause of traffic fatalities and injuries among young drivers. This meta-analysis examined whether brief alcohol interventions were effective in reducing driving after drinking among adolescents and young adults. Our systematic search identified 12 experimental/quasi-experimental evaluations (16 intervention groups) that measured driving while intoxicated and related consequences and provided data for effect size calculation (N = 5,664; M age =17 years; 57% male). The studies were published between 1991 and 2011. Three-level random-effects meta-analyses using a structural equation modeling approach were used to summarize the effects of the interventions. Compared with controls, participants in brief alcohol interventions reported reduced drinking and driving and related consequences (ḡ = 0.15, 95% CI [0.08, 0.21]). Supplemental analyses indicated that reductions in driving while intoxicated were positively associated with the reduced post-intervention heavy use of alcohol. These findings were not attenuated by study design or implementation factors. Brief alcohol interventions under 5 hours of contact may constitute a promising preventive approach targeting drinking and driving among adolescents and young adults. Reducing heavy episodic alcohol consumption appeared to be a major factor in reducing drunk-driving instances. Interpretation of the findings must be made with caution, however, given the possibility of publication bias and the small observed effect size. Future research should focus on the exact mechanisms of behavior change leading to beneficial outcomes of brief alcohol interventions and the potential effectiveness of combined brief interventions and other preventive approaches.