Are mass-media campaigns effective in preventing drug use? A Cochrane systematic review and meta-analysis.
OBJECTIVE
To determine whether there is evidence that mass-media campaigns can be effective in reducing illicit drug consumption and the intent to consume.


METHODS
Systematic review of randomised and non-randomised studies.


METHODS
We searched four electronic databases (MEDLINE, EMBASE, ProQuest Dissertations & Theses A&I and CENTRAL) and further explored seven additional resources to obtain both published and unpublished materials. We appraised the quality of included studies using standardised tools. We carried out meta-analyses of randomised controlled trials and a pooled analysis of interrupted time-series and controlled before-and-after studies.


RESULTS
We identified 19 studies comprising 184,811 participants. Pooled analyses and narrative synthesis provided mixed evidence of effectiveness. Eight interventions evaluated with randomised controlled trials leaned towards no evidence of an effect, both on drug use (standardised mean difference (SMD) -0.02; 95% CI -0.15 to 0.12) and the intention to use drugs (SMD -0.07; 95% CI -0.19 to 0.04). Four campaigns provided some evidence of beneficial effects in preventing drug use and two interventions provided evidence of iatrogenic effects.


CONCLUSIONS
Studies were considerably heterogeneous in type of mass-media intervention, outcome measures, underlying theory, comparison groups and design. Such factors can contribute to explaining the observed variability in results. Owing to the risk of adverse effects, caution is needed in disseminating mass-media campaigns tackling drug use. Large studies conducted with appropriate methodology are warranted to consolidate the evidence base.
Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy School of Public Health, University of Torino, Torino, Italy.
Elias
http://orcid.org/0000-0002-1634-8330
E
Allara
Consequences, Responses and Best Practices Unit, European Monitoring Centre for Drugs and Drug Addiction, Lisbon, Portugal.
Marica
M
Ferri
Consequences, Responses and Best Practices Unit, European Monitoring Centre for Drugs and Drug Addiction, Lisbon, Portugal.
Alessandra
A
Bo
Department of Medical Statistics, London School of Hygiene & Tropical Medicine, London, UK.
Antonio
A
Gasparrini
Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy.
Fabrizio
F
Faggiano
D006293:Health Promotion / Q000379:methods*; D006801:Humans; D008402:Mass Media; D015233:Models, Statistical; D017063:Outcome Assessment, Health Care; D019966:Substance-Related Disorders / Q000517:prevention & control*
Health policy < HEALTH SERVICES ADMINISTRATION & MANAGEMENT; MENTAL HEALTH; PUBLIC HEALTH; Substance misuse < PSYCHIATRY