The consistency of estimates obtained through central-location sampling: analysis of the Partnership for a Drug-Free America Attitude Tracking Study

Media campaigns for the prevention of illicit drug use in young people

BACKGROUND

Substance-specific mass media campaigns which address young people are widely used to prevent illicit drug use. They aim to reduce use and raise awareness of the problem.

OBJECTIVES

To assess the effectiveness of mass media campaigns in preventing or reducing the use of or intention to use illicit drugs amongst young people.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library 2013, Issue 1), including the Cochrane Drugs and Alcohol Group's Specialised Register; MEDLINE through PubMed (from 1966 to 29 January 2013); EMBASE (from 1974 to 30 January 2013) and ProQuest Dissertations & Theses A&I (from 1861 to 3 February 2013).

SELECTION CRITERIA

Cluster-randomised controlled trials, prospective and retrospective cohort studies, interrupted time series and controlled before and after studies evaluating the effectiveness of mass media campaigns in influencing drug use, intention to use or the attitude of young people under the age of 26 towards illicit drugs.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures of The Cochrane Collaboration.

MAIN RESULTS

We included 23 studies involving 188,934 young people, conducted in the USA, Canada and Australia between 1991 and 2012. Twelve studies were randomised controlled trials (RCT), two were prospective cohort studies (PCS), one study was both a RCT and a PCS, six were interrupted time series and two were controlled before and after (CBA) studies. The RCTs had an overall low risk of bias, along with the ITS (apart from the dimension 'formal test of trend'), and the PCS had overall good quality, apart from the description of loss to follow-up by exposure.Self reported or biomarker-assessed illicit drug use was measured with an array of published and unpublished scales making comparisons difficult. Pooled results of five RCTs (N = 5470) show no effect of media campaign intervention (standardised mean difference (SMD) -0.02; 95% confidence interval (CI) -0.15 to 0.12).We also pooled five ITS studies (N = 26,405) focusing specifically on methamphetamine use. Out of four pooled estimates (two endpoints measured in two age groups), there was evidence of a reduction only in past-year prevalence of methamphetamine use among 12 to 17 years old.A further five studies (designs = one RCT with PCS, two PCS, two ITS, one CBA, N = 151,508), which could not be included in meta-analyses, reported a drug use outcome with varied results including a clear iatrogenic effect in one case and reduction of use in another.

AUTHORS' CONCLUSIONS

Overall the available evidence does not allow conclusions about the effect of media campaigns on illicit drug use among young people. We conclude that further studies are needed.

An empirical assessment of the Above the Influence advertising campaign

This study evaluated the efficacy of Above the Influence (ATI), a national media-based health persuasion campaign to deter youth drug use. The campaign uses public service anti-drug prevention messages and targets youth between the ages of 14 and 16, a period of heightened susceptibility to peer influences. The evaluation utilized mall intercepts from geographically dispersed regions of the country. Theoretical impetus for the campaign combines elements of the theory of reasoned action (TRA), persuasion theory, and the health belief model. A series of structural equation models were tested with four randomly drawn cross-validation samples (N = 3,000). Findings suggest that awareness of ATI is associated with greater anti-drug beliefs, fewer drug use intentions, and less marijuana use. Congruent with the TRA, changes in beliefs and intentions are intermediate steps linking campaign awareness with behavior. This study provides further evidence of positive campaign effects and may strengthen reliance on mass media health persuasion campaigns as a useful adjunct to other programs targeting youth.

Assessing the impact of antidrug advertising on adolescent drug consumption: results from a behavioral economic model

OBJECTIVES

This study examined whether adolescents' recall of antidrug advertising is associated with a decreased probability of using illicit drugs and, given drug use, a reduced volume of use.

METHODS

A behavioral economic model of influences on drug consumption was developed with survey data from a nationally representative sample of adolescents to determine the incremental impact of antidrug advertising.

RESULTS

The findings provided evidence that recall of antidrug advertising was associated with a lower probability of marijuana and cocaine/crack use. Recall of such advertising was not associated with the decision of how much marijuana or cocaine/crack to use. Results suggest that individuals predisposed to try marijuana are also predisposed to try cocaine/crack.

CONCLUSIONS

The present results provide support for the effectiveness of antidrug advertising programs.