Normative perceptions of cannabis use amongst European University students: associations between perceived peer use and peer attitudes with personal use and attitudes.

Objective: Perceptions of peer behavior and attitudes exert considerable social pressure on young adults to use substances. This study investigated whether European students perceive their peers’ cannabis use and approval of cannabis use to be higher than their own personal behaviors and attitudes, and whether estimations of peer use and attitudes are associated with personal use and attitudes. Method: University students (n = 4131) from Belgium, Denmark, Germany, the Slovak Republic, Spain, Turkey and the United Kingdom completed an online survey as part of the Social Norms Intervention for Polysubstance usE in students (SNIPE) project, a feasibility study of a web-based normative feedback intervention for substance use. The survey assessed students’ (1) personal substance use and attitudes, and (2) perceptions of their peers’ cannabis use (descriptive norms) and attitudes (injunctive norms). Results: Although most respondents (92%) did not personally use cannabis in the past two months, the majority of students thought that the majority of their peers were using cannabis and that their peers had more permissive attitudes towards cannabis than themselves. Controlling for students’ age, sex, study year and religious beliefs, perceived peer descriptive norms were associated with personal cannabis use (OR: 1.42; 95% CI: 1.22, 1.64) and perceived injunctive norms were associated with personal attitudes towards cannabis use (OR: 1.46; 95% CI: 1.09, 1.94). Conclusions: European students appear to possess similar discrepancies between personal and perceived peer norms for cannabis use and attitudes as found in North American students. Interventions which address such discrepancies may be effective in reducing cannabis use. Keywords: cannabis, social norms, student health, social influenc

Personal and perceived peer use and attitudes towards the use of nonmedical prescription stimulants to improve academic performance among university students in seven European countries

© 2016 Background Overestimations of non-prescribed stimulant use of peers are well documented in the USA and have also been identified as predictive of personal stimulant consumption. This study aimed to examine whether overestimations of peer use and approval of the use are associated with personal use and attitude towards the use of non-prescribed stimulants among European university students. Method The EU funded ‘Social Norms Intervention for the prevention of Polydrug usE (SNIPE)’ study was conducted in seven European countries. In a web-based questionnaire, 4482 students were asked about their personal use and their attitude towards non-prescribed stimulant use, as well as the perceived peer use and peer attitude. Results 59% of students thought that the majority of their peers used non-prescribed stimulants more frequently than themselves, and only 4% thought that the use of the majority was lower than their personal use. The perception that the majority of peers had used non-prescribed stimulants at least once was significantly associated with higher odds for personal use of non-prescribed stimulants (OR: 3.30, 95% CI: 2.32–4.71). In addition, the perception that the majority of peers approved of the non-prescribed use of stimulants was associated with a 4.03 (95% CI: 3.35–4.84) times higher likelihood for personal approval. Discussion European university students generally perceived the non-prescribed use of stimulants of peers to be higher than their personal use. This perception, as well as a perception of higher approval in the peer group, was associated with a higher likelihood of personal non-prescribed stimulant medication use and approval

Equity-specific effects of interventions to promote physical activity among middle-aged and older adults: results from applying a novel equity-specific re-analysis strategy

Background Reducing inequalities in physical activity (PA) and PA-associated health outcomes is a priority for public health. Interventions to promote PA may reduce inequalities, but may also unintentionally increase them. Thus, there is a need to analyze equity-specific intervention effects. However, the potential for analyzing equity-specific effects of PA interventions has not yet been sufficiently exploited. The aim of this study was to set out a novel equity-specific re-analysis strategy tried out in an international interdisciplinary collaboration. Methods The re-analysis strategy comprised harmonizing choice and definition of outcomes, exposures, socio-demographic indicators, and statistical analysis strategies across studies, as well as synthesizing results. It was applied in a collaboration of a convenience sample of eight European PA intervention studies in adults aged ≥45 years. Weekly minutes of moderate-to-vigorous PA was harmonized as outcome. Any versus no intervention was harmonized as exposure. Gender, education, income, area deprivation, and marital status were harmonized as socio-demographic indicators. Interactions between the intervention and socio-demographic indicators on moderate-to-vigorous PA were analyzed using multivariable linear regression and random-effects meta-analysis. Results The collaborative experience shows that the novel re-analysis strategy can be applied to investigate equity-specific effects of existing PA interventions. Across our convenience sample of studies, no consistent pattern of equity-specific intervention effects was found. Pooled estimates suggested that intervention effects did not differ by gender, education, income, area deprivation, and marital status. Conclusions To exploit the potential for equity-specific effect analysis, we encourage future studies to apply the strategy to representative samples of existing study data. Ensuring sufficient representation of ‘hard to reach’ groups such as the most disadvantaged in study samples is of particular importance. This will help to extend the limited evidence required for the design and prioritization of future interventions that are most likely to reduce health inequalities

Comparison of three meta-analytic methods using data from digital interventions on type 2 diabetes

Mihiretu M Kebede,1–3 Manuela Peters,1,2 Thomas L Heise,1,2 Claudia R Pischke2 1Department of Public Health, University of Bremen, Health Sciences, Bremen, Germany; 2Department of Prevention and Evaluation, Leibniz Institute for Prevention Research and Epidemiology – BIPS, Bremen, Germany; 3Department of Health Informatics, University of Gondar, College of Medicine and Health Science, Institute of Public Health, Gondar, Ethiopia Aims: Pooling the effect sizes of randomized controlled trials (RCTs) from continuous outcomes, such as glycated hemoglobin level (HbA1c), is an important method in evidence syntheses. However, due to challenges related to baseline imbalances and pre/post correlations, simple analysis of change scores (SACS) and simple analysis of final values (SAFV) meta-analyses result in under- or overestimation of effect estimates. This study was aimed to compare pooled effect sizes estimated by Analysis of Covariance (ANCOVA), SACS, and SAFV meta-analyses, using the example of RCTs of digital interventions with HbA1c as the main outcome.Materials and methods: Three databases were systematically searched for RCTs published from 1993 through June 2017. Two reviewers independently assessed titles and abstracts using predefined eligibility criteria, assessed study quality, and extracted data, with disagreements resolved by arbitration from a third reviewer.Results: ANCOVA, SACS, and SAFV resulted in pooled HbA1c mean differences of –0.39% (95% CI: [–0.51, –0.26]), –0.39% (95% CI: [–0.51, –0.26]), and –0.34% (95% CI: [–0.48–0.19]), respectively. Removing studies with both high baseline imbalance (≥±0.2%) and pre/post correlation of ≥±0.6 resulted in a mean difference of –0.39% (95% CI: [–0.53, –0.26]), –0.40% (95% CI: [–0.54, –0.26]), and –0.33% (95% CI: [–0.48, –0.18]) with ANCOVA, SACS, and SAFV meta-analyses, respectively. Substantial heterogeneity was noted. Egger’s test for funnel plot symmetry did not indicate evidence of publication bias for all methods.Conclusion: By all meta-analytic methods, digital interventions appear effective in reducing HbA1c in type 2 diabetes. The effort to adjust for baseline imbalance and pre/post correlation using ANCOVA relies on the level of detail reported from individual studies. Reporting detailed summary data and, ideally, access to individual patient data of intervention trials are essential. Keywords: baseline imbalance, ANCOVA, change scores, final values, systematic reviews, HbA1c, diabetes, eHealt