Testing the effects of e-mailed personalized feedback on risky alcohol use among college students

The effectiveness of digital health technologies for reducing substance use among young people: a systematic review & meta-analysis

BACKGROUND

Substance use amongst young people poses developmental and clinical challenges, necessitating early detection and treatment. Considering the widespread use of technology in young people, delivering interventions digitally may help to reduce and monitor their substance use.

AIMS

We conducted a systematic review and two meta-analyses to assess the effectiveness of digital interventions for reducing substance use (alcohol, smoking, and other substances) among young people aged 10 to 24 years old.

METHOD

Embase, Global Health, Medline, PsychINFO, Web of Science and reference lists of relevant papers were searched in November 2020. Studies were included if they quantitatively evaluated the effectiveness of digital health technologies for treating substance use. A narrative synthesis and meta-analysis were conducted.

RESULTS

Forty-two studies were included in the systematic review and 18 in the meta-analyses. Digital interventions showed small, but statistically significant reductions in weekly alcohol consumption compared to controls (SMD= -0.12, 95% CI= -0.17 to -0.06, I2=0%), but no overall effect was seen on 30-day smoking abstinence (OR = 1.12, 95% CI = 0.70 to 1.80, I2=81%). The effectiveness of digital interventions for reducing substance use is generally weak, however, promising results such as reducing alcohol use were seen. Large-scale studies should investigate the viability of digital interventions, collect user feedback, and determine cost-effectiveness.

PRISMA/PROSPERO

This systematic review was conducted following Cochrane methodology PRISMA guidelines. The review was registered with PROSPERO in November 2020 (CRD42020218442).

Finding the Right Balance: A Social Norms Intervention to Reduce Heavy Drinking in University Students

Introduction: Heavy alcohol consumption constitutes a major health risk among University students. Social relationships with peers strongly affect University students' perception of the drinking behavior of others, which in turn plays a crucial role in determining their own alcohol intake. University students tend to overestimate their peers' alcohol consumption – a belief that is associated with an increase in an individual's own consumption. Therefore, we implemented a social norms intervention with personalized normative feedback at a major University in Germany to reduce and prevent excessive drinking among University students.

Methods: Our intervention was part of a regular health monitoring survey. We invited all enrolled University students to take part in this survey on two occasions. A total of 862 University students completed the questionnaire, 563 (65.3%) of which received e-mail-based feedback upon request concerning their peers' and their own alcohol consumption. For the intervention group (n = 190) as well as the control group (no feedback requested; n = 101), we included only University students in the evaluation who overestimated their peers' alcohol use and indicated above average consumption of the peers. We applied analyses of variance to assess intervention effects with regard to the correction of overestimated group norms as well as University students' drinking behavior.

Results: Within the intervention group, we observed a significantly larger reduction of the previously overestimated behavioral norms compared to the control group (p < 0.001; ηp2 = 0.06). With regard to behavioral outcomes the intervention group showed a significantly larger reduction in the AUDIT-C score (p = 0.020; ηp2 = 0.03).

Discussion: Our study confirms previous research whereupon personalized, gender-specific and selective normative feedback is effective for alcohol prevention among University students. However, University students still overestimated their peers' alcohol intake after the intervention. Furthermore, we did not reach high-risk groups (University students with the highest alcohol intake) since no feedback was requested. Future studies should address factors influencing the impact of the intervention and reachability of selective groups.

Does Advice Based on Biomarkers of Liver Injury or Non-Invasive Tests of Liver Fibrosis Impact High-Risk Drinking Behaviour: A Systematic Review With Meta-analysis

BACKGROUND AND AIMS

Alcohol dependence affects over 240 million people worldwide and attributed to 3 million deaths annually. Early identification and intervention are key to prevent harm. We aim to systematically review literature on the effectiveness of adding advice based on biomarkers of liver injury or non-invasive tests of liver fibrosis (intervention-based advice) to prevent alcohol misuse.

METHODS

Electronic search was conducted on Ovid Medline, PubMed, EMBASE, Psychinfo and CINAHL for articles published up to end of February 2020. Additionally, we searched study citations, Scopus, Ethos and Clinical trials. The primary outcome measure was changed in self-reported alcohol consumption analysed by random-effects meta-analysis. Secondary outcomes included change to liver blood markers and alcohol-related health outcomes.

RESULTS

Fourteen randomized controlled trials (RCTs) and two observational studies comprising n = 3763 participants were included. Meta-analyses showed a greater reduction in alcohol consumption and liver biomarkers for the intervention compared to control group: mean difference for weekly alcohol intake was -74.4 g/week (95% confidence interval (CI) -126.1, -22.6, P = 0.005) and mean difference for gamma-glutamyl transferase (GGT) -19.7 IU/l (95% CI -33.1, -6.4, P = 0.004). There was a higher incidence of alcohol-attributed mortality, number of days spent in the hospital, physician visits and sickness absence in the non-intervention group. The quality of the included studies was moderate for RCTs and high for observational studies.

CONCLUSIONS

The review confirmed a significant association between the addition of intervention-based advice in routine care to the reduction of harmful alcohol consumption, GGT and alcohol-related mortality. The findings support the inclusion of this type of advice in routine alcohol care.

Comparative Effectiveness of Brief Alcohol Interventions for College Students: Results from a Network Meta-Analysis

Late adolescence is a time of increased drinking, and alcohol plays a predominant role in college social experiences. Colleges seeking to prevent students' hazardous drinking may elect to implement brief alcohol interventions (BAIs). However, numerous manualized BAIs exist, so an important question remains regarding the comparative effectiveness of these different types of BAIs for college students. This study uses network meta-analyses (NMA) to compare seven manualized BAIs for reducing problematic alcohol use among college students. We systematically searched multiple sources for literature, and we screened studies and extracted data in duplicate. For the quantitative synthesis, we employed a random-effects frequentist NMA to determine the effectiveness of different BAIs compared to controls and estimated the relative effectiveness ranking of each BAI. A systematic literature search resulted in 52 included studies: On average, 58% of participants were male, 75% were binge drinkers, and 20% were fraternity/sorority-affiliated students. Consistency models demonstrated that BASICS was consistently effective in reducing students' problematic alcohol use (ES range: g = - 0.23, 95%CI [- 0.36, - 0.16] to g = - 0.36, 95% CI [- 0.55, - 0.18]), but AlcoholEDU (g = - 0.13, 95%CI [- 0.22, - 0.04]), e-CHUG (g = - 0.35, 95%CI [- 0.45, - 0.05]), and THRIVE (g = - 0.47, 95%CI [- 0.60, - 0.33]) were also effective for some outcomes. Intervention rankings indicated that BASICS, THRIVE, and AlcoholEDU hold the most promise for future trials. Several BAIs appear effective for college students. BASICS was the most effective but is resource intensive and may be better suited for higher risk students; THRIVE and e-CHUG are less resource intensive and show promise for universal prevention efforts.

Pragmatic randomized controlled trial of a web-based intervention for alcohol use among Brazilian college students: Motivation as a moderating effect

BACKGROUND

Web-based personalized normative feedback (PNF) interventions are less effective than their laboratory versions. Participant motivation may account for this reduced effect, but there is only a limited amount of research into the influence of motivation on PNF effectiveness. We evaluated the effectiveness of a web-based PNF in reducing alcohol use and consequences among college students with different motivation levels.

METHODS

Pragmatic randomized controlled trial among Brazilian college drinkers aged 18-30 years (N = 4460). Participants were randomized to a Control or PNF group and followed-up after one (T1), three (T2) and six (T3) months. Outcomes were: AUDIT score (primary outcome), the number of consequences, and the typical number of drinks. Motivation for receiving the intervention was assessed with a visual analog scale (range: 0-10). Generalized mixed models assessed intervention effects via two paradigms: observed cases and attrition models.

RESULTS

PNF reduced the number of typical drinks at T1 (OR = 0.71, p = 0.002), T2 (OR = 0.60, p < 0.001) and T3 (OR = 0.68, p = 0.016), compared to the control. Motivated students (score ≥3) receiving PNF also reduced the number of typical drinks at T1 (OR = 0.60, p < 0.001), T2 (OR = 0.55, p < 0.001) and T3 (OR = 0.56, p = 0.001), compared to the control. However, the attrition models were more robust at T1 and T2. In contrast, low-motivated students receiving the PNF increased AUDIT score at T3 (b = 1.49, p < 0.001).

CONCLUSIONS

The intervention reduced alcohol use, and motivation for receiving the intervention moderated the intervention effects. Motivated students reduced their typical alcohol use, whereas low-motivated students increased their AUDIT score.

[Internet-based alcohol interventions for college students: systematic reviewIntervenciones por Internet para reducir el consumo de alcohol de los estudiantes universitarios: revisión sistemática]

Objective

To identify the main modalities of Internet-based interventions to limit alcohol use among university students, and to describe the effects of these interventions on alcohol use and related consequences.

Methods

A systematic review of PubMed, PsycINFO, and SciELO was performed using as search terms "alcohol drinking AND Internet," without date or language restrictions. Inclusion criteria were randomized controlled trial design, focus on college students and on Internet-based interventions, and evaluating the effects of the intervention on alcohol use or alcohol-related consequences.

Results

Thirty-six articles were analyzed. Two main intervention modalities were identified: personalized normative feedback (PNF, n=28) and multicomponent interventions (n=8). Twelve studies with PNF reported reductions in alcohol use 3 months after the intervention. Multicomponent interventions reduced alcohol use and related consequences; most studies focused on the website AlcoholEdu, which reduced alcohol consumption and the consequences of alcohol use 6 months after the intervention.

Conclusions

FNP and the AlcoholEdu website, the most frequently evaluated interventions among the selected studies, were effective in reducing alcohol use in university students. These strategies are an alternative to increase the access of university students to interventions aimed at limiting alcohol use.

Efficacy of interventions targeting alcohol, drug and smoking behaviors in university and college students: A review of randomized controlled trials

OBJECTIVE

To evaluate the effectiveness of interventions targeting alcohol consumption, drug use and smoking for college/university students.

PARTICIPANTS

College/University students.

METHODS

Studies were eligible if: (1)included students attending universities/colleges; (2)implemented in a university/college setting; (3)aimed to improve at least one of the following behaviors: alcohol and/or drug use and/or smoking; (4)were RCTs. The effect of the interventions on behaviors was determined by the percentage of studies that reported an effect. Due to the heterogeneity of outcomes meta-analysis was not conducted.

RESULTS

88 studies met criteria. University-based interventions were effective for reducing alcohol-related outcomes (drinking patterns, BAC, consequences, problem drinking). Inconsistent findings for drug and smoking were observed.

CONCLUSIONS

University-based interventions have the potential to improve health for students. While there is a breadth of research examining the efficacy of interventions to reduce alcohol consumption, further research is needed to determine the best approach for addressing smoking and drug use among students.

Personalised digital interventions for reducing hazardous and harmful alcohol consumption in community-dwelling populations

BACKGROUND

Excessive alcohol use contributes significantly to physical and psychological illness, injury and death, and a wide array of social harm in all age groups. A proven strategy for reducing excessive alcohol consumption levels is to offer a brief conversation-based intervention in primary care settings, but more recent technological innovations have enabled people to interact directly via computer, mobile device or smartphone with digital interventions designed to address problem alcohol consumption.

OBJECTIVES

To assess the effectiveness and cost-effectiveness of digital interventions for reducing hazardous and harmful alcohol consumption, alcohol-related problems, or both, in people living in the community, specifically: (i) Are digital interventions more effective and cost-effective than no intervention (or minimal input) controls? (ii) Are digital interventions at least equally effective as face-to-face brief alcohol interventions? (iii) What are the effective component behaviour change techniques (BCTs) of such interventions and their mechanisms of action? (iv) What theories or models have been used in the development and/or evaluation of the intervention? Secondary objectives were (i) to assess whether outcomes differ between trials where the digital intervention targets participants attending health, social care, education or other community-based settings and those where it is offered remotely via the internet or mobile phone platforms; (ii) to specify interventions according to their mode of delivery (e.g. functionality features) and assess the impact of mode of delivery on outcomes.

SEARCH METHODS

We searched CENTRAL, MEDLINE, PsycINFO, CINAHL, ERIC, HTA and Web of Knowledge databases; ClinicalTrials.com and WHO ICTRP trials registers and relevant websites to April 2017. We also checked the reference lists of included trials and relevant systematic reviews.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that evaluated the effectiveness of digital interventions compared with no intervention or with face-to-face interventions for reducing hazardous or harmful alcohol consumption in people living in the community and reported a measure of alcohol consumption.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

We included 57 studies which randomised a total of 34,390 participants. The main sources of bias were from attrition and participant blinding (36% and 21% of studies respectively, high risk of bias). Forty one studies (42 comparisons, 19,241 participants) provided data for the primary meta-analysis, which demonstrated that participants using a digital intervention drank approximately 23 g alcohol weekly (95% CI 15 to 30) (about 3 UK units) less than participants who received no or minimal interventions at end of follow up (moderate-quality evidence).Fifteen studies (16 comparisons, 10,862 participants) demonstrated that participants who engaged with digital interventions had less than one drinking day per month fewer than no intervention controls (moderate-quality evidence), 15 studies (3587 participants) showed about one binge drinking session less per month in the intervention group compared to no intervention controls (moderate-quality evidence), and in 15 studies (9791 participants) intervention participants drank one unit per occasion less than no intervention control participants (moderate-quality evidence).Only five small studies (390 participants) compared digital and face-to-face interventions. There was no difference in alcohol consumption at end of follow up (MD 0.52 g/week, 95% CI -24.59 to 25.63; low-quality evidence). Thus, digital alcohol interventions produced broadly similar outcomes in these studies. No studies reported whether any adverse effects resulted from the interventions.A median of nine BCTs were used in experimental arms (range = 1 to 22). 'B' is an estimate of effect (MD in quantity of drinking, expressed in g/week) per unit increase in the BCT, and is a way to report whether individual BCTs are linked to the effect of the intervention. The BCTs of goal setting (B -43.94, 95% CI -78.59 to -9.30), problem solving (B -48.03, 95% CI -77.79 to -18.27), information about antecedents (B -74.20, 95% CI -117.72 to -30.68), behaviour substitution (B -123.71, 95% CI -184.63 to -62.80) and credible source (B -39.89, 95% CI -72.66 to -7.11) were significantly associated with reduced alcohol consumption in unadjusted models. In a multivariable model that included BCTs with B > 23 in the unadjusted model, the BCTs of behaviour substitution (B -95.12, 95% CI -162.90 to -27.34), problem solving (B -45.92, 95% CI -90.97 to -0.87), and credible source (B -32.09, 95% CI -60.64 to -3.55) were associated with reduced alcohol consumption.The most frequently mentioned theories or models in the included studies were Motivational Interviewing Theory (7/20), Transtheoretical Model (6/20) and Social Norms Theory (6/20). Over half of the interventions (n = 21, 51%) made no mention of theory. Only two studies used theory to select participants or tailor the intervention. There was no evidence of an association between reporting theory use and intervention effectiveness.

AUTHORS' CONCLUSIONS

There is moderate-quality evidence that digital interventions may lower alcohol consumption, with an average reduction of up to three (UK) standard drinks per week compared to control participants. Substantial heterogeneity and risk of performance and publication bias may mean the reduction was lower. Low-quality evidence from fewer studies suggested there may be little or no difference in impact on alcohol consumption between digital and face-to-face interventions.The BCTs of behaviour substitution, problem solving and credible source were associated with the effectiveness of digital interventions to reduce alcohol consumption and warrant further investigation in an experimental context.Reporting of theory use was very limited and often unclear when present. Over half of the interventions made no reference to any theories. Limited reporting of theory use was unrelated to heterogeneity in intervention effectiveness.

Examining personalized feedback interventions for gambling disorders: A systematic review

Background and aims Personalized feedback interventions (PFI) have shown success as a low-cost, scalable intervention for reducing problematic and excessive consumption of alcohol. Recently, researchers have begun to apply PFI as an intervention method for problematic gambling behaviors. A systematic review of the literature on PFI as an intervention/prevention method for gambling behaviors was performed. Methods Studies were included if they met the following criteria: the design included both a PFI group and a comparison group, and the interventions focused on gambling prevention and/or reduction. Six relevant studies were found meeting all criteria. Results Results revealed that PFI treatment groups showed decreases in a variety of gambling behaviors as compared to control groups, and perceived norms on gambling behaviors significantly decreased after interventions as compared to control groups. Conclusions Overall, the research suggests that while PFI applied to gambling is still in its infancy, problematic gamblers appear to benefit from programs incorporating PFIs. Further, PFI may also be used as a promising source of preventative measures for individuals displaying at-risk gambling behaviors. While, evidence is still limited, and additional research needs to be conducted with PFI for gambling problems, the preliminary positive results along with the structure of PFI as a scalable and relatively inexpensive intervention method provides promising support for future studies.

Social norms information for alcohol misuse in university and college students

BACKGROUND

Drinking is influenced by youth perceptions of how their peers drink. These perceptions are often incorrect, overestimating peer drinking norms. If inaccurate perceptions can be corrected, young people may drink less.

OBJECTIVES

To determine whether social norms interventions reduce alcohol-related negative consequences, alcohol misuse or alcohol consumption when compared with a control (ranging from assessment only/no intervention to other educational or psychosocial interventions) among university and college students.

SEARCH METHODS

The following electronic databases were searched up to July 2015: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE, PsycINFO. The Cumulative Index to Nursing and Allied Health Literature (CINAHL) only to March 2008. Reference lists of included studies and review articles were manually searched. No restriction based on language or date was applied.

SELECTION CRITERIA

Randomised controlled trials or cluster-randomised controlled trials that compared a social normative intervention versus no intervention, alcohol education leaflet or other 'non-normative feedback' alcohol intervention and reported on alcohol consumption or alcohol-related problems in university or college students.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by Cochrane. Each outcome was analysed by mode of delivery: mailed normative feedback (MF); web/computer normative feedback (WF); individual face-to-face normative feedback (IFF); group face-to-face normative feedback (GFF); and normative marketing campaign (MC).

MAIN RESULTS

A total of 70 studies (44,958 participants) were included in the review, and 63 studies (42,784 participants) in the meta-analyses. Overall, the risk of bias assessment showed that these studies provided moderate or low quality evidence.Outcomes at four or more months post-intervention were of particular interest to assess when effects were sustained beyond the immediate short term. We have reported pooled effects across delivery modes only for those analyses for which heterogeneity across delivery modes is not substantial (I(2) < 50%).Alcohol-related problems at four or more months: IFF standardised mean difference (SMD) -0.14, 95% confidence interval (CI) -0.24 to -0.04 (participants = 2327; studies = 11; moderate quality evidence), equivalent to a decrease of 1.28 points in the 69-point alcohol problems scale score. No effects were found for WF or MF.Binge drinking at four or more months: results pooled across delivery modes: SMD -0.06, 95% CI -0.11 to -0.02 (participants = 11,292; studies = 16; moderate quality evidence), equivalent to 2.7% fewer binge drinkers if 30-day prevalence is 43.9%.Drinking quantity at four or more months: results pooled across delivery modes: SMD -0.08, 95% CI -0.12 to -0.04 (participants = 21,169; studies = 32; moderate quality evidence), equivalent to a reduction of 0.9 drinks consumed each week, from a baseline of 13.7 drinks per week.Drinking frequency at four or more months: WF SMD -0.11, 95% CI -0.17 to -0.04 (participants = 9929; studies = 10; moderate quality evidence), equivalent to a decrease of 0.17 drinking days/wk, from a baseline of 2.74 days/wk; IFF SMD -0.21, 95% CI -0.31 to -0.10 (participants = 1464; studies = 8; moderate quality evidence), equivalent to a decrease of 0.32 drinking days/wk, from a baseline of 2.74 days/wk. No effects were found for GFF or MC.Estimated blood alcohol concentration (BAC) at four or more months: peak BAC results pooled across delivery modes: SMD -0.08, 95% CI -0.17 to 0.00 (participants = 7198; studies = 11; low quality evidence), equivalent to a reduction in peak BAC from an average of 0.144% to 0.135%. No effects were found for typical BAC with IFF.

AUTHORS' CONCLUSIONS

The results of this review indicate that no substantive meaningful benefits are associated with social norms interventions for prevention of alcohol misuse among college/university students. Although some significant effects were found, we interpret the effect sizes as too small, given the measurement scales used in the studies included in this review, to be of relevance for policy or practice. Moreover, the significant effects are not consistent for all misuse measures, heterogeneity was a problem in some analyses and bias cannot be discounted as a potential cause of these findings.

The Use of the Internet for Prevention of Binge Drinking Among the College Population: A Systematic Review of Evidence

AIMS

There are many consequences of binge drinking compared with light or moderate drinking behaviors. The prevalence rate and intensity of binge drinking is highest among the college-aged population. Given the popularity and high use of the Internet among college students, a novel approach for programming is through Internet-based interventions. The purpose of this study was to conduct a systematic review of Internet-based interventions targeting binge drinking among the college population.

METHODS

Eligibility criteria included peer-reviewed articles evaluating Internet-based interventions for binge drinking prevention among college students published between 2000 and 2014. Only English language articles were included. Review articles and articles only explaining intervention pedagogies were not included. After a systematic screening process, a total of 14 articles were included for the final review. Each article was read thoroughly in order to extract the following variables: study design and sample size, average age of participants, underpinning theoretical framework, and intervention description and duration. This review also synthesized a methodological assessment with variables such as outcome measures, sample size justification, number of measurements and use of process evaluations.

RESULTS

All studies but one reported a significant reduction in the frequency and quantity of alcohol consumption and problems related with heavy drinking. Furthermore, Internet-based interventions appeared to be more effective than traditional print-based interventions; however, face-to-face interventions were typically more effective.

CONCLUSIONS

This review supports using the Internet as a brief intervention approach that can effectively support efforts to reduce binge drinking among college students.

Using CBPR Methods in College Health Research

Community-based participatory research (CBPR) is a collaborative methodology that uniquely involves stakeholders in all stages of the research process. CBPR has been widely utilized in the field of public health, but not widely employed with college populations. This study utilized CBPR methods within a college community to gain insight into excessive alcohol consumption. Six student researchers planned and carried out a rigorous qualitative study at a public university in the Northeast region of the United States. A total of 48 undergraduate participants were recruited for focus groups that were facilitated by two student researchers, and transcribed and analyzed using thematic analysis methods. Students’ reasons for drinking alcohol were focused within the themes of inclusion, habitual default, and the student development process. Social media, strict policy/enforcement, and student’s desire to avoid responsibility led to increased risk and consequences related to drinking. Students recommended late night transportation and a Good Samaritan policy as strategies to improve student safety. This study led to student advocacy and policy change directed at improving student’s health and safety and demonstrated that CBPR methods show promise for engaging students and producing meaningful data.

Novel Approaches to Individual Alcohol Interventions for Heavy Drinking College Students and Young Adults

Efficacious alcohol interventions for college students and young adults have been developed but produce small effects of limited duration. This paper provides a review and critique of novel (e.g., a significant deviation from a traditional, brief, and motivational intervention) interventions published between 2009 and 2014 to reduce alcohol use in this population and covers intervention format/components and efficacy on alcohol outcomes. We reviewed 12 randomized controlled trials of novel, individual-level alcohol interventions that reported alcohol outcomes. Four domains of novel interventions are discussed: content (e.g., pharmaco-therapy and automatic action tendency retraining), setting (e.g., health centers and ED), modality (e.g., mobile technology), and treatment integration. Findings were mixed for intervention efficacy to reduce amount and frequency of alcohol consumption. Few studies assessed impact on alcohol-related problems. Despite the prevalence of efficacious interventions, there is still an urgent need for novel treatment approaches and delivery mechanisms for this difficult-to-treat population.

Social norms information for alcohol misuse in university and college students

BACKGROUND

Drinking is influenced by youth (mis)perceptions of how their peers drink. If misperceptions can be corrected, young people may drink less.

OBJECTIVES

To determine whether social norms interventions reduce alcohol-related negative consequences, alcohol misuse or alcohol consumption when compared with a control (ranging from assessment only/no intervention to other educational or psychosocial interventions) among university and college students.

SEARCH METHODS

The following electronic databases were searched up to May 2014: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (only to March 2008). Reference lists of included studies and review articles were manually searched.

SELECTION CRITERIA

Randomised controlled trials or cluster-randomised controlled trials that compared a social normative intervention versus no intervention, alcohol education leaflet or other 'non-normative feedback' alcohol intervention and reported on alcohol consumption or alcohol-related problems in university or college students.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by The Cochrane Collaboration. Each outcome was analysed by mode of delivery: mailed normative feedback (MF); Web/computer normative feedback (WF); individual face-to-face normative feedback (IFF); group face-to-face normative feedback (GFF); and normative marketing campaign (MC).

MAIN RESULTS

A total of 66 studies (43,125 participants) were included in the review, and 59 studies (40,951 participants) in the meta-analyses. Outcomes at 4+ months post intervention were of particular interest to assess when effects were sustained beyond the immediate short term. We have reported pooled effects across delivery modes only for those analyses for which heterogeneity across delivery modes is not substantial (I(2) < 50%). Alcohol-related problems at 4+ months: IFF standardised mean difference (SMD) -0.16, 95% confidence interval (CI) -0.31 to -0.01 (participants = 1065; studies = 7; moderate quality of evidence), equivalent to a decrease of 1.5 points in the 69-point alcohol problems scale score. No effects were found for WF or MF. Binge drinking at 4+ months: results pooled across delivery modes: SMD -0.06, 95% CI -0.11 to -0.02 (participants = 11,292; studies = 16; moderate quality of evidence), equivalent to 2.7% fewer binge drinkers if 30-day prevalence is 43.9%. Drinking quantity at 4+ months: results pooled across delivery modes: SMD -0.08, 95% CI -0.12 to -0.05 (participants = 20,696; studies = 33; moderate quality of evidence), equivalent to a reduction of 0.9 drinks consumed each week, from a baseline of 13.7 drinks per week. Drinking frequency at 4+ months: WF SMD -0.12, 95% CI -0.18 to -0.05 (participants = 9456; studies = 9; moderate quality of evidence), equivalent to a decrease of 0.19 drinking days/wk, from a baseline of 2.74 days/wk; IFF SMD -0.21, 95% CI -0.31 to -0.10 (participants = 1464; studies = 8; moderate quality of evidence), equivalent to a decrease of 0.32 drinking days/wk, from a baseline of 2.74 days/wk. No effects were found for GFF or MC. Estimated blood alcohol concentration (BAC) at 4+ months: peak BAC results pooled across delivery modes: SMD -0.08, 95% CI -0.17 to 0.00 (participants = 7198; studies = 13; low quality of evidence), equivalent to a reduction in peak PAC from an average of 0.144% to 0.135%. No effects were found for typical BAC with IFF.

AUTHORS' CONCLUSIONS

The results of this review indicate that no substantive meaningful benefits are associated with social norms interventions for prevention of alcohol misuse among college/university students. Although some significant effects were found, we interpret the effect sizes as too small, given the measurement scales used in the studies included in this review, to be of relevance for policy or practice. Moreover, the statistically significant effects are not consistent for all misuse measures, heterogeneity was a problem in some analyses and bias cannot be discounted as a potential cause of these findings.