A review of 25 long-term adolescent tobacco and other drug use prevention program evaluations

Abstract

Background

Although the initial effectiveness of psychosocial strategies programming in preventing smoking and other drug abuse among adolescents has been well established through literature reviews and meta-analyses, much less evidence exists for the long-term follow-up success of these interventions. The primary goal of this paper, therefore, is to summarize the effectiveness of published program evaluation studies that have followed adolescents across the transitional period between junior high and high school for a period of at least 2 years.

Methods

Studies for inclusion in this review were accessed primarily through a computerized search of Medline, Healthstar, and PsychINFO databases. Intervention studies that met five core criteria were retained for review. Two authors independently abstracted data on study characteristics, methodology, and program outcomes.

Results

Search results yielded 25 studies suitable for examination. The majority of these studies reported significant program effects for long-term smoking, alcohol, and marijuana outcomes, while indicating a fairly consistent magnitude of program effects.

Conclusions

This review provides long-term empirical evidence of the effectiveness of social influences programs in preventing or reducing substance use for up to 15 years after completion of programming. However, this conclusion is still somewhat tenuous given the lack of significant program effects reported in several studies and the great variability that existed in the level of internal and external validity across all studies.

Introduction

Despite recent national data indicating small and sporadic declines in adolescent drug use over the past decade [1], tobacco, alcohol, and marijuana are still the most widely abused substances by both younger and older American teenagers. In 2001, the proportions of 8th, 10th, and 12th graders who reported use of cigarettes in the past 30 days were 12.2, 21.3, and 29.5%, respectively. At the same time, alcohol and marijuana use remained extremely widespread with respective 30-day prevalence rates of 21.5, 39.0, and 49.8% for alcohol use and 9.2, 19.8, and 22.4% for marijuana use.

The period of peak risk for the onset of drug problems begins in adolescence, a period spanning the ages 10 to 20. During the early adolescent years, individuals experience major biological, cognitive, social, and emotional changes that influence behavioral choices, such as experimentation with health-compromising substances including tobacco and alcohol, the gateway drugs that increase the likelihood of progression to more advanced forms of drug use [2]. For a significant number of individuals, such risk-taking behavior may lead to the formation of more enduring health behavior patterns including a lifetime development of drug dependence [3]. Moreover, those who initiate drug use at an earlier age are at greater risk for later drug abuse [4]. Thus, preventing or delaying the onset of drug use in early adolescence is of critical importance.

Over the past few decades, wellness advocates [5] stimulated considerable drug prevention research efforts that have resulted in a variety of educational programs that typically address the primary prevention of tobacco, alcohol, and marijuana use among adolescents through school-based programs. The most recent and promising prevention approaches are based on the psychosocial influences that promote drug use initiation. The two major psychosocial approaches that have been adopted by schools are the social influences approach [6] and the more comprehensive personal and social competence enhancement (Life Skills Training) strategy [7]. Social influences programs are designed to increase the awareness of the social influences promoting drug use, alter norms regarding the prevalence and acceptability of drug use, and build drug resistance skills. Personal and social competence enhancement programs incorporate aspects of the social influence approach and also include general self-management and social competence skills.

Literature reviews [8], [9], [10] and meta-analyses [11], [12], [13] of these social influences programs have indicated short-term (under 24 months) reductions in the rate of initiation of tobacco use generally ranging from 30 to 50% or more in students exposed to social influences programs compared to control students. To a lesser extent, positive short-term results for alcohol and marijuana use have also been reported [12], [13], with reductions typically ranging from 15 to 30% or more for alcohol and marijuana use. Although the initial effectiveness of psychosocial strategies programming in preventing—or at least delaying—smoking and other drug abuse among adolescents has been demonstrated, much less evidence exists for the long-term follow-up success of these substance use interventions. In fact, the current and prevalent folk wisdom—even among drug prevention scientists—is that initial program effects will necessarily start to decay and disappear altogether once programming has concluded. This notion was generated in the absence of a systematic review of existing empirical studies that have assessed program effects for a minimum 24-month follow-up period.

To date, there has been no specific review of the long-term effectiveness of tobacco, alcohol, and other drug use prevention programming among adolescents. The goal of this paper, therefore, is to summarize empirical evidence on the effectiveness of school- and community-based prevention programs by critically reviewing all published long-term evaluation studies that have followed adolescents (across the transitional period between junior high and high school) for a period of at least 2 years. Information from the individual studies is examined to obtain an overview of research designs and methodologies of the prevention trials that have been implemented and to summarize the effectiveness of these evaluations in terms of percentage of reductions in drug use in adolescence. Also of interest is whether the preventive effects, found in studies that demonstrated strong initial results, are maintained beyond 2 years. Implications of the findings are then considered for future prevention programming activity.