Effects of a Brief Web-Based "Social Norms"-Intervention on Alcohol, Tobacco and Cannabis Use Among German University Students: Results of a Cluster-Controlled Trial Conducted at Eight Universities

Background and Aim: "Social norms" (SN)-interventions are aimed at changing existing misperceptions regarding peer substance use by providing feedback on actual norms, thereby affecting personal substance use. It is unknown whether SN-intervention effects previously demonstrated in US students can be replicated in German students. The aim of the INSIST-study was to examine the effects of a web-based SN-intervention on substance use. Design: Cluster-controlled trial. Setting: Eight Universities in Germany. Participants and Measurements: Students were recruited at four intervention vs. four delayed intervention control Universities. 4,463 students completed baseline, 1,255 students (59% female) completed both baseline and 5-months follow-up web-based surveys on personal and perceived peer substance use. Intervention participants received feedback contrasting personal and perceived peer use with previously assessed use and perceptions of same-sex, same-university peers. Intervention effects were assessed via multivariable mixed logistic regression models. Findings: Relative to controls, reception of SN-feedback was associated with higher odds for decreased alcohol use (OR: 1.91, 95% CI 1.42-2.56). This effect was most pronounced in students overestimating peer use at baseline and under or accurately estimating it at follow-up (OR: 6.28, 95% CI 2.00-19.8). The OR was 1.33 (95% CI 0.67-2.65) for decreased cannabis use in students at intervention Universities and was statistically significant at 1.70 (95% CI 1.13-2.55) when contrasting unchanged and decreased with increased use. Regarding tobacco use and episodes of drunkenness, no intervention effects were found. Conclusions: This study was the first cluster-controlled trial suggesting beneficial effects of web-based SN-intervention on alcohol and cannabis use in a large sample of German University students. Clinical Trial Registration: The trial registration number of the INSIST-study is DRKS00007635 at the "German Clinical Trials Register."

Equity impacts of interventions to increase physical activity: A health impact assessment

Background

Behavioural interventions may increase social inequalities in health. This study aimed to project the equity impact of physical activity interventions that have differential effectiveness across education groups on the long-term health inequalities among older adults in Germany.

Methods

We created six hypothetical intervention scenarios targeting adults aged 55 years and above: Scenarios #1 to #4 applied realistic intervention effects that varied by education. Under scenario #5, the lower and medium educated group adapted the physical activity pattern of the higher educated. Under scenario #6, all persons increased their physical activity level to the recommended 300 minutes weekly. The number of incident ischemic heart disease, stroke and diabetes cases as well as deaths from all causes was simulated under each of these six intervention scenarios for males and females over a 10-year projection period using the DYNAMO-HIA tool, and compared against a reference scenario with unchanged physical activity pattern.

Results

For males, the highest reduction of disease cases and deaths would be achieved under scenario #4 (most effective in higher educated persons), while increasing inequalities between education groups. For females, the highest reduction would be achieved under scenario #3 (most effective in lower educated persons), while decreasing inequalities between education groups. Scenarios #1 to #4 would prevent only a fraction of the disease cases and deaths that would be avoided under scenario #5 or scenario #6.

Conclusions

This modelling study shows how the overall population health impact varies, depending on how intervention-induced physical activity changes differ across education groups. For decision-makers, both the assessment of health impacts overall as well as within a population is relevant, as interventions with the greatest population health gain might be accompanied by an unintended increase in health inequalities.

Key messages

Health impact assessments with a focus on equity are essential for decision-makers. In order to correctly project population health effects, and choose between options of intervention types from a public health perspective, data on subgroup-specific intervention effects are needed.

[Effectiveness of School-based Interventions for the Prevention and/or Reduction of Psychosocial Problems among Children and Adolescents: A Review of Reviews]

Objective: To summarize the current evidence on the effectiveness of school-based interventions for the maintenance of mental health and the prevention of psychosocial problems among pupils. Methods: A systematic literature search of reviews published between 2007 and 2015 was carried out. Databases searched included Medline, PsycINFO, Campbell Library, Cochrane Library, NICE, ERIC, and Web of Science. Study selection, data extraction, and quality assessment (using AMSTAR criteria) were performed by 2 independent reviewers. Results: 6 reviews covering 331 primary studies were included in this review of reviews. Findings of three reviews with a focus on the maintenance and/or promotion of mental health and general well-being suggested that interventions aimed at changes in the social and the school environment were more effective than those that only targeted individual behavior change among pupils. Interventions for the reduction of mobbing/bullying were most effective if they comprised organizational changes at schools, such as playground and schoolyard supervision, and disciplinary measures. One review suggested strong evidence for the effectiveness of classroom management to reduce violent behavior among pupils. Conclusions: Participation in interventions promoting changes in the school environment, in addition to individual behavior change, appears to be associated with improved mental health among pupils and reductions in mobbing/bullying and violent behavior at schools.