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National Conference on Drug Abuse Prevention Research:
Presentations, Papers, and Recommendations

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Plenary Session

Prevention Programs: What Are the Critical Factors That Spell Success?

William B. Hansen, Ph.D.
President
Tanglewood Research, Inc.


National Conference on Drug Abuse Prevention Research

Introduction

After a decade of funding dedicated to reducing drug use that has averaged between $1 billion and $1.5 billion per year, the United States is currently experiencing an increase in illicit drug use among school-age youth (Johnston et al. 1996). This significant public investment, surely needed to reduce the prevalence of drug use, did not have the desired outcome. The challenge of preventing drug use will remain elusive until, as a society and body politic, we learn the essential lessons needed for success.

Fortunately, hope is available from scientific research, including examples of successful programs. Indeed, had the knowledge available today been actively applied during the past dec-ade, it is likely that the drug use situation would be different. This paper reviews the scientific principles of prevention that must be understood and applied for prevention efforts to be successful.


Epidemiologic Trends in Use

An epidemic of illicit drug use emerged among young people in the United States in the 1960s and continued to expand through the 1970s. Marijuana was the most popular illicit drug, with use among high school seniors gaining majority status. In the high school class of 1979, 60.4 percent reported having used marijuana (Johnston et al. 1996). Use of marijuana peaked around 1979 or 1980, and the decade of the 1980s saw a consistent decline to a point where annual prevalence was cut in half, going from one in two seniors in the class of 1979, to one in four seniors in the class of 1991. Marijuana use increased between 1975 and 1978, when the proportion of seniors reporting use of marijuana on a daily or near-daily basis in the past 30 days rose from 6.0 percent to an unprecedented 10.7 percent. Fortunately, that figure subsequently declined by more than 80 percent, reaching 2.0 percent in 1991. Recently, there has been a substantial turnaround. Daily use rates were 3.6 percent in 1994 and reveal a trend of increase that has not leveled off (Johnston et al. 1996).

Cocaine use among high school seniors did not decline until after 1986. Cocaine use increased dramatically in the late 1970s and stayed constant among adolescents in the early 1980s. The early 1990s have seen neither increases nor decreases in cocaine use.

Use of inhalants generally increased throughout the 1990s. Among high school seniors, the annual use rate observed in 1993 was 7.0 percent, the highest since observations began in 1975. This class of drug has become the most used substance (other than tobacco and alcohol) among younger students (Edwards 1993; Hansen and Rose 1995). Another substance that has shown recent signs of a reemergence is LSD (lysergic acid diethylamide), which had an annual prevalence among 1993 high school seniors of 6.8 percent, the highest level recorded since 1975 (when it was 7.2 percent). Use rates increased for all three grades between 1991 and 1994. Amphetamines are yet another class of drugs that showed increases in use for all three grades between 1991 and 1994.

The decline in illicit drug use between 1980 and 1990 has been largely attributed to the Omnibus Anti-Drug Act, which pumped hundreds of millions of dollars into schools and communities to combat illicit drug use. However, two facts should be noted. First, the start of the decline in the use of marijuana, amphetamines, sedatives, and tobacco predated the expenditure of Federal funds and continued at about the same rate despite the infusion of Federal dollars. For example, between 1978 and 1986 (the year the Omnibus Anti-Drug Act was passed by Congress), the average rate of decline in 30-day illicit drug use was 1.8 percent per year. Between 1987 and 1991, the average rate of decline increased, but only minimally, to 2.1 percent per year.

Second, the recent turnabout in the use of some drugs corresponded to a period of relatively high levels of funding, when programs, training, and infrastructure were in place. These considerations are particularly important given our understanding of the time course of drug use development. Among youth, the proportion of students who use drugs increases gradually from middle or junior high school, not abruptly at the 11th or 12th grade. This suggests that the turnabout observed in high school seniors in 1992 may have had its beginnings several years earlier.

There are many disturbing aspects of the recent trends in use of illicit drugs among students in the United States. Only a short time ago, it appeared that illicit drug use was on a downward trajectory, which was comforting for parents, teachers, and community leaders. The recent trajectories for a number of drugs - drugs that are important because of their considerable potential for serious damage - are clearly not so comforting now. This evidence suggests that funded efforts in schools and communities have not been highly effective. Because of the overall failure of initial efforts to produce long-term changes in drug use, standard practices must now be dramatically improved. Models are clearly needed to bolster confidence that effective preventive practices can be identified, adopted, implemented, confirmed, and sustained. Truly effective drug use prevention methods that are adopted and maintained at a significant level should be expected to meaningfully suppress all measures of drug prevalence. Our goal should be to focus on the adoption of scientifically grounded preventive intervention methods that can produce a definable turnaround in the current trend of increasing drug use.


Prevention

Prevention research has focused extensively on three drugs: alcohol, tobacco, and marijuana. Cocaine has received extensive media coverage and is a target of interdiction by law enforcement. However, cocaine has not been targeted in adolescent research programs, primarily because its use has a relatively low prevalence among adolescents, and because cocaine and other "hard" drugs are seldom initiated without the earlier regular use of alcohol, tobacco, and marijuana (Graham et al. 1991; Kandel 1978; Kandel et al. 1992). The trend of high inhalant use is too recent for a significant body of research to have emerged (Edwards 1993; Hansen and Rose 1995).

The goal of prevention is to delay, deter, or eliminate the onset of substance use within populations. At the core of prevention programs are several assumptions that deserve consideration. It is now widely recognized that effective prevention programs have several common features (Dusenbury and Falco 1995; Hansen 1992; Tobler and Stratton 1997). This paper elaborates and comments on several of these topical features that are crucial to success. Features are presented in order of importance for determining program success. Specifically, this review focuses on evidence for program effectiveness based on program focus, delivery technique, evaluation, and training and support.


Program Focus

Program focus, the message of the program and what the program attempts to change, is the most important element of preventive intervention. Program focus describes how the program is supposed to work and what immediate outcome the program is trying to produce that will eventually result in a change in the onset of drug use.

The history of prevention suggests three periods of program development. The first period can be characterized as well-intended efforts driven by common sense, ideology, or intuition.

The second period is characterized as being theory-driven. The third period, only currently emerging, will ultimately be characterized as data-driven. This paper focuses on what has been learned from school-based efforts, primarily because most of the published research is in this domain; however, the principles gleaned from this research should be readily applicable to other settings.

Intuition-Driven Prevention

Intuition-driven prevention programs were often developed by individuals who had little formal training in an academic discipline but who viewed drug use as an issue that called for social action. Various approaches qualify as intuitive approaches. Programming efforts often focused on the health consequences of drug use. Having former addicts present their stories and describe the horrors of addiction was commonplace. Other approaches stressed understanding what drugs looked like, how they were injected or ingested, and how they were sold. By and large, intuitive efforts have not been evaluated. Most are not packaged in a manner allowing program definition that is amenable to evaluation or research.

Justification of these approaches often referred to common sense assumptions. Nearly every citizen has a ready explanation of drug use. Those explanations that seemed logical were the most likely to be adopted. For example, there is a clear logical connection between the fact that drug use is harmful and that the nature of the harm should be communicated. Many people viewed those who used drugs as having low self-esteem. The logical corollary of such a view was that prevention programs should focus on improving self-esteem. A number of good ideas have emerged from applying intuitive thinking to prevention; however, intuitive ideas alone do not always produce effective methods for intervention and can result in ideological thinking that may interfere with the adoption of more productive methods.

Intuitive methods have resulted in numerous commercial products. Only recently have commercially available programs been evaluated. Three curriculums in particular have captured a sizable segment of the prevention program market, DARE (Drug Abuse Resistance Education), Quest: Skills for Living, and Here's Looking at You, 2000. Of these, only evaluations of DARE have been reported in sufficient numbers to draw conclusions.

The DARE program consists of materials created by the Los Angeles Unified School District. Some materials were borrowed from eclectic research-based programs that were developed in the early 1980s but were redeveloped to fit with an ideology consonant with police officer-delivery of the program; it is largely intuitive in its approach. The program is delivered by uniformed police officers who have received extensive training at one of five regional training centers. DARE is delivered annually to about 5 1/2 million students in the United States. The program is delivered in all 50 States and has made international connections as well.

The magnitude of the program notwithstanding, there is little evidence to support DARE as a viable or effective approach to substance abuse prevention. In a recent review by Ennett and colleagues (1994), 17 published and unpublished manuscripts documenting evaluations of DARE were examined. Of the 17, only 11 met minimal standards for methodological rigor and were used to form the basis of interpreting findings. None of these studies demonstrated any outcome effectiveness of DARE. The average calculated effect size reported was .06, indicating very small average effects. Overall, drug use among control schools and DARE schools was roughly equal. Several of these studies were longitudinal and found neither short- nor long-term results. Moreover, DARE has been most heavily institutionalized since 1990, a period during which drug use has been escalating.

Other packages that have been widely adopted include such programs as Quest: Skills for Living, Project Adventure, Ombudsman, BABES, Project CHARLIE, Children Are People, and Here's Looking at You, 2000. There are no adequate evaluation results by which the effectiveness of these programs can be judged (Thorne, personal communication). Evaluations that have been conducted have primarily been short-term evaluations for dissertations and theses and lack interpretable behavioral end points (Swisher, personal communication). All programs, including those that are intuition-driven, should be evaluated to determine potential effectiveness.

Theory-Driven Prevention

What distinguishes theory-driven from intuition-driven efforts is a reliance on a body of formalized research. Many early theory-driven approaches relied on research findings that, although relevant to drug use, were not the direct result of the application of research to drug use problems. Thus, social psychologists drew from strategies that reflected the theories of their discipline, such as social learning theory (Bandura 1977), much of which initially came from the study of aggression among children, and the theory of reasoned action (Ajzen and Fishbein 1980), which initially focused on a host of social behaviors other than drug use. Sociologists drew from social control theory (Hirschi 1969), which focused early attention on delinquent behavior. Developmental psychologists focused on skill and competency theories (Higgins et al. 1983) and theories that addressed affective social development (Watson et al. 1989). Researchers grounded in public health issues used the health belief model (Becker 1974), which originally focused on a variety of health behaviors, not specifically on preventing drug use among adolescents.

Beginning in the 1970s (e.g., Evans et al. 1978) and continuing through the 1980s, numerous field trials were held in which various combinations of elements were delivered and long-term followup tracking of behavioral effects was completed. By and large, these field trials focused on programs that were theory-driven. For example, Evans and colleagues were the first to identify social perception and processes related to social influences and to draw from social psychological theory in the development of intervention strategies. These efforts relied on a combination of host-discipline theory (that is, theories in which the program developer was trained as a student) and intuition (often not admitted) to guide program development. Moreover, there was an open eclecticism in which bits and pieces of multiple theories were often assembled to create a matrix of theoretical support for any given intervention.

Numerous reviews have been completed about the effectiveness of theory-driven curricular approaches to prevention. These reviews have spanned the spectrum and have made a unique contribution to understanding the field of prevention. Tobacco use prevention studies have been extensively reviewed (e.g., Best et al. 1988; Botvin and Wills 1985, pp. 8-49; Evans and Raines 1982; Flay 1985; Leventhal and Cleary 1980; Thompson 1978). Alcohol has been the focus of several reviews (Goodstadt 1980; Gordon and McAlister 1982; Moskowitz 1989). Reviews that are specific and limited to examining the prevention of marijuana or cocaine use do not exist. However, several reviews have included an examination of use prevention for multiple substances (Bangert-Drowns 1988; Coie et al. 1993; Moskowitz 1989; Schaps et al. 1981; Tobler 1986; Tobler and Stratton 1997).

Previous reviewers have faced the problem of creating a meaningful classification scheme. For example, Tobler (1986) examined major themes by researchers reporting results and proposed five summary program categories to describe functional content groupings: knowledge only, affective only, peer, knowledge plus affective, and alternatives.

Bangert-Drowns (1988) similarly classified programs into three types according to functional content: information only, affective education only, or mixed. On the other hand, Coie et al. (1993) based their classification on theory types rather than program types and came up with four types of program components: rational, social reinforcement, social norm, and developmental. Coie and colleagues demonstrate that there is some similarity between their conceptualization of the theoretical underpinnings of prevention programs and those suggested by other reviewers (Bernstein and McAlister 1969; Thompson 1978; Leventhal and Cleary 1980; Moskowitz et al. 1983; Schaps 1981).

In other reviews, Hansen (1992), Tobler (1986), and Tobler and Stratton (1997) have independently presented categorization schemes that are highly similar to those presented above. Four functional categories of programs were identified by each author. For Hansen (1992), classification schemes were based solely on program content. Resulting groups of curriculums included information and values clarification programs, affective programs that also included information components, social influence programs that also tended to include information, and multiple component programs that usually included some element of all three of the previous groups but emphasized social influence in conjunction with additional affective strategies.

More recently, Tobler and Stratton (1997) have suggested seven content areas: knowledge, affective education, refusal skills, generic skills, safety skills, extracurricular activities, and other strategies. Although this broadens the conceptualization of programming, little is available about the potential of any specific program strategy.

There is some intersection among these classification schemes. Notably, social processes, generic skills, and knowledge often emerge as themes of intervention programs. Such generalizations allow synthesis researchers to gain an understanding of the effects of general approaches. Unfortunately, such categorizations are too broad to allow for a precise classification of programs and often obscure specific program elements that may be important to the design of prevention programs. Preventive interventions consist of complex sets of instructions. Broad categories provide few insights about what constitutes the effective agent of a preventive intervention.

Researcher-generated programs are more often evaluated than commercially developed programs, because evaluations are essential to the process of research-based efforts. However, until recently, the resources needed to complete these evaluations have been lacking. The effectiveness of school-based curricular approaches has been widely questioned (Moskowitz 1989). The primary difficulty in gaining an understanding of which strategies hold promise concerns methodological difficulties in conducting field trials to evaluate the effectiveness of these strategies. Nonetheless, two recent reviews (Hansen 1992; Tobler and Stratton, 1997) suggest that, despite these difficulties, there are promising findings, particularly among the program types that include social influence approaches.

Hansen (1992) reviewed the effects of programming on outcome variables from 45 published and unpublished studies. The results revealed positive outcomes for the following types of programs: information, 31 percent; affective education, 19 percent; social influence, 51 percent; and multiple component, 50 percent. In contrast, negative outcomes were found for the following types of programs: information, 25 percent; affective education, 19 percent; social influence, 11 percent; and multiple component, zero percent. Outcomes that were neither positive nor negative were common among all program categories; information programs (44 percent), multiple component programs (50 percent), and affective programs (62 percent) had more nonsignificant results than social influence programs (38 percent).

Overall, social influence and multiple component programs, which also typically featured social influence strategies as major components, had more positive results than either information-based approaches or affective education approaches. This overall pattern was maintained when studies with methodological weaknesses were deleted. Among these analyses, only 30 percent of information-based and 42 percent of affective programs had significant findings as compared to 63 percent of social influence strategies, and 72 percent of multiple component strategies.

Tobler and Stratton (1997) used means and standard deviations to calculate effect-size statistics for each of the studies cited above. Their review increased the number of studies in the analysis and conducted analyses on two data sets. The first included all reported studies for which effect sizes could be determined. The second included only those studies from the larger group that met methodological standards for inclusion (adequate followup, control groups, etc.).

Programs that were primarily informational or affective in nature had relatively small effect sizes. In contrast, programs that featured social influence approaches or included life skills approaches in addition to social influence approaches were relatively effective. Such programs include Project SMART (Hansen et al. 1988), Project STAR (Pentz et al. 1989), and Life Skills Training (Botvin et al. 1990).

Data-Driven Prevention

More recently, researchers have systematically attempted the development of a science of prevention (Coie et al. 1993; Hansen and McNeal 1996) that rests on empirical findings about etiology (Pandina, this volume). The essential difference between data- and theory-driven programs is that empirical evidence about mediating variables dictates the content of interventions. Data-driven programs require that interventions abandon methods that address variables that have weak statistical relationships with drug use.

On the other hand, theory-based interventions do not exclude intervention strategies that fit with a theoretical model even if data supporting that method are not particularly strong. Data-driven programs ignore theory; insights from theory are used identically for both theory- and data-driven programs. As a result, theory has not been abandoned, but it is second in priority to empirical findings. Explanation is important only once empirical relationships have been established. However, theory does not drive the selection of variables for intervention.

Research on substance abuse etiology has examined numerous variables that serve as markers of these concepts, and empirical findings can be used to demonstrate the potential of prevention programs to affect behavior. The essential logic of the etiologic approach is that a program must target a variable that statistically accounts for behavior. Variables that do not account for differences between users and nonusers, or between users and abusers, hold little promise for being able to influence programmatic outcomes. Furthermore, variables must be changeable. Gender, ethnicity, age, socioeconomic status, and basic personality characteristics - such as a tendency to take risks - are variables that often predict drug use. These variables are almost always considered in program design. However, these variables are not likely to be changed by a program and are therefore not the primary concern in selection of what a program is to change.

The focus on data-driven approaches began with mediating variable analyses of theory-driven programs (MacKinnon et al. 1991) and field trials in which tests compared programs that isolated specific subcomponents (Hansen and Graham 1991; Donaldson et al. 1994). Pioneering work completed by MacKinnon and his colleagues (1991) analyzed the mediating variable paths through which the Midwest Prevention Project intervention worked. These analyses demonstrated that much of the effect of the tested curriculum was statistically attributable to changes in normative beliefs and changes in beliefs about consequences that were targeted by the curriculum. Several elements of the program, such as resistance skills, were judged to be inert because they lacked mediating variable significance.

The Adolescent Alcohol Prevention Trial (Hansen and Graham 1991) tested the effects of a program that focused on establishing conventional norms and of a program that focused on teaching skills for resisting peer and other social pressures. Significant main effects were observed for the program that focused on normative education, whereas the program that focused on resistance skills was essentially no different than that for controls. Subsequent analyses (Donaldson et al. 1994) revealed that the resistance skills program had potential for effectiveness, but only when students were motivated from the outset to learn skills.

It is increasingly recognized that program success is determined primarily by the degree to which programs change the characteristics of students, schools, neighborhoods, and families that statistically or mathematically account for changes in drug use. Two laws of program effectiveness have recently been proposed (Hansen and McNeal 1996). The first, the law of indirect effect, posits that programs must operate by changing mediating variables (that is, changing modifiable risk and protective factors). The second, the law of maximum expected potential effect, posits that only programs that target and change characteristics that statistically account for drug use have the potential to succeed. Programs that fail to target appropriate characteristics or that target appropriate characteristics but fail to produce needed change cannot and will not succeed.

A meta-analysis of 242 studies revealed that 11 major types of variables have been examined in etiologic studies (Hansen et al. 1993): previous drug use, intentions to use drugs, cognitive factors, competency factors, personality factors, institutional influences, drug use by others, pressures to use drugs, peer group characteristics, home factors, and demographics such as age, gender, and ethnicity.

Drug use has long been known to be the single best correlate of the concurrent use of other substances and the best predictor of future drug use behavior. Substance use is habitual, and many substances are known to be addictive, creating severe withdrawal [symptoms] when discontinued. However, it is important to note that factors other than habit and addiction account for variations in an individual's behavior over time. Therefore, a primary goal of prevention should be to postpone and suppress drug use.

The "drug use by others" category had a relatively strong correlation. Drug use by peers was more strongly correlated with self-reported drug use and drug use by siblings than with parental drug use. Beliefs about the psychological and social consequences of and attitudes toward drug use also had strong average correlations. Beliefs about health consequences were not as strongly correlated. Reported pressures to use substances, which included offers from peers and parents, as well as perceived attitudes about drug use among others, had large average correlations. Bonding and commitment to school had a strong correlation with substance use, as did deviance.

Several categories of variables had weak relationships with substance use. The weakest observed category of variables was home factors, including the psychological traits of parents, parent-child relationship, parental marital status, parental education, family composition, and socioeconomic status. These factors are different from parental attentiveness, parenting style, and parental drug use, which tended to have higher correlations.

Other variable groups included institutional influences such as church attendance and affiliation and participation in sports and other structured activities. A weak relationship existed between the substance use and competence and personality variables, including self-esteem, moodiness, and locus of control. Demographic variables, such as race and gender, all had average correlations.


Twelve Targets of Prevention Programs

Research in progress (Hansen 1996a; Hansen and Graham [unpublished]; Hansen and McNeal 1997) provides additional information about etiology that aids in understanding the potential of different programmatic approaches to prevent onset of drug use. The research examined 12 mediating variables that were hypothesized to act as change agents in substance use prevention programs (Hansen 1992).

  1. Normative Beliefs - Perceptions about the prevalence of drug use among close friends and same-age peers at school and the acceptability of substance use among friends. Perceptions are often exaggerated; teens think drug use is more prevalent and more acceptable than it really is.

  2. Lifestyle/Behavior Incongruence - The degree to which the student views substance use as incongruent with personally held current lifestyle and future aspirations. Teens who perceive their desired lifestyle as not fitting with drug use are hypothesized to be protected.

  3. Commitment - Personal commitments regarding substance use. Topics include public statements of intentionality (for example, "I have signed my name somewhere to show that I have promised not to use drugs"). Items also assessed a student's private intentions (for example, "I have made a personal commitment to never smoke cigarettes").

  4. Beliefs About Consequences - Beliefs about social, psychological, and health consequences, including being part of a group, being less shy, doing embarrassing things in a group, having fun, having bad breath, having health problems, dealing with personal problems, and the probability of getting into trouble.

  5. Resistance Skills - Perceived ability to identify and resist pressure to use alcohol, tobacco, and marijuana. This refers to an individual's ability to say "no."

  6. Goal-Setting Skills - Application of goal-setting skills and behaviors, including frequently establishing goals, developing strategies for achieving goals, and persistence.

  7. Decision Skills - The degree to which teens understand and apply a rational strategy for making decisions.

  8. Alternatives - Awareness of and participation in enjoyable activities that do not involve substance use.

  9. Self-Esteem - The degree to which teens feel personal worth and perceive themselves to have characteristics that contribute to a positive self-evaluation.

  10. Stress Management Skills - Perceived skills for coping with stress, including skills for relaxing as well as for confronting challenging situations.

  11. Social Skills - Ability to establish friendships, be assertive with friends, and get along with others.

  12. Assistance Skills - The degree to which students believe they are able to give assistance to others who have personal problems. Included in this concept is the ability to find help for oneself when experiencing personal difficulties.

Mediating variables were compared on the basis of their ability to predict subsequent self-reported substance use. The variables most strongly associated with future drug use were normative beliefs, values, and commitment. Moderately strong, but consistently less predictive, were self-efficacy to resist peer pressure and beliefs about consequences of drug use. These results, based on 1-year lagged correlational data collected from 2,639 sixth- through ninth-grade students, demonstrate that substance use prevention programs that target correcting erroneous normative beliefs, creating a perception that substance use will interfere with a young person's desired lifestyle, and building personal commitments may have optimal potential for success. Because the magnitude of correlation is expected to be directly related to the potential for a program to result in behavior change (Hansen and McNeal 1996), it is clear that choosing the correct set of mediators for intervention may have a clear payoff in behavior change terms.

An important advance that accompanies the development of data-driven prevention is a reliance on mediating variable analysis statistics to determine the reasons for program success or failure. These statistics (MacKinnon 1994, pp. 127-154; MacKinnon and Dwyer 1993) allow researchers to calculate the degree to which changes in behavior are the result of having changed mediators. The primary implication of mediating variable analysis methods is the ability to use data about mediators and drug use outcomes to determine empirically how program effects were achieved, defining the essence of data-driven strategies for prevention program development.

Mediating variable analysis methods can be applied to any program as long as a mediating variable is measured. These methods were recently applied to understanding how the DARE program works (Hansen and McNeal 1997). These analyses demonstrate that the lack of effects of DARE is related to insufficient impact on the program elements that must be changed to produce a preventive effect on behavior. For instance, DARE had an effect on improving the commitment of students, but the effect was too small to have a large impact on behavior. Other variables that are targeted by DARE, such as peer pressure resistance skills and normative beliefs, were not significantly or meaningfully changed.

Two problems may be at the root of the lack of success to date of applied prevention activities. First, few programs target the right sets of mediating variables. Second, even among those programs that do address variables that have a strong potential to mediate drug use, there is little demonstrated evidence that such programs have a strong impact on these variables. One program that was recently developed to specifically respond to these findings has been All Stars (Hansen 1996b). This program addresses four mediators - building incongruence between desired lifestyles and high-risk behaviors, establishing conventional norms and correcting erroneous normative beliefs, building strong personal commitments to avoid high-risk behavior, and developing prosocial bonds. To date, only pilot-test data are available. Compared with students who received the seventh-grade DARE program, students who received the All Stars program had significantly better outcomes on each mediator.


Conclusions About Program Focus

Success in school-based drug use prevention requires the development of a significant knowledge base. Without it, preventive approaches will fail more often than they succeed. Currently, the school-based prevention field is characterized and dominated by individuals and groups who believe strongly in the value of prevention. However, such activist approaches to prevention more often rely on a determination to succeed rather than the technical knowledge to achieve their goals. Unfortunately, such approaches seldom, if ever, achieve prevention goals. No matter how widespread, politically viable, or popular a program may be, effectiveness in preventing the onset of substance use and abuse must remain the primary and sole criterion by which programs are judged.

In contrast to the state of the practice, the state of the art in prevention programming clearly favors programs that are data-driven. Programs must target and change mediating variables that are strongly predictive of substance use development. Evidence suggests that the most promising targets for prevention programming include establishing conventional normative beliefs, building strong personal commitments, and developing prosocial bonds with school and other prosocial institutions, such as the church and the Boy Scouts and Girl Scouts. Other targets that may prove valuable include resistance skills training (see caveats in Hansen and Graham 1991 and Donaldson et al. 1994), developing perceived incongruence between lifestyle and drug use (not yet tested empirically), and developing general competence. Given the correlations between drug use and delinquency, including premature sexual activity, prevention programs should address broader issues.

Many of the approaches that have been popular in the past, including building self-esteem, teaching generic social skills, and teaching specific skills such as stress management, are not likely to be effective in school-based prevention. Programs that target these characteristics may fulfill other needs but are not likely to be effective as preventive tools. Current prevention programs focus on a diverse set of mediators. Programs can be improved by refocusing attention on changing variables that have the potential to mediate behavior.


Delivery Technique

Relatively little research that systematically varies the style of program delivery has been conducted. The evidence that does exist is largely drawn from Tobler's meta-analytic studies (Tobler 1986; Tobler and Stratton, 1997), which have examined the style of program delivery across many different quasi-experimental trials. Even though limited, the evidence is compelling. Tobler and Stratton (1997) present comparisons between programs that were judged to be interactive versus those judged to be noninteractive. Interactive programs were those in which students were actively engaged through discussion, role-plays, and games. Noninteractive programs were those that relied heavily on lecture, film and videotape, and silent worksheet-type activities. In seven of eight analyses in which the behavioral outcomes of interactive and noninteractive programs were compared, interactive programs had significantly more overall effectiveness.

These findings have an important implication for the design of prevention programs for students. Despite increasing efforts to develop interactive methods, teaching methods have traditionally relied heavily on noninteractive methods. A significant shift in these methods may be required before effective prevention can be achieved.

Because relatively little research is available from randomized drug prevention studies, benchmarks are challenging to establish. One recent review of prevention programs made judgments about the interactiveness of programs based on an evaluation of written materials (Falco 1996). However, it clearly becomes a challenge to judge such programs in the abstract. Many of the programs included in meta-analyses are completed under relatively good supervision. Program integrity has been clearly linked to outcome in prior research (Rohrbach et al. 1993). Training and other support that can help guarantee the fidelity of program implementation should be given.

A basic definition of interaction has not yet been developed. One might presume that one-way communications (preaching, lecture, film without discussion, demonstrations) are not interactive. However, it is not clear what variety of activities constitutes interaction. The goals of interaction are to engage participants in an active and positive way. Discussion can be more or less interactive, depending on how emotionally involved, attentive, reflective, and actively involved students become. Teaching skills through games and role-plays is also more likely to engage participants.

When research is completed, some forms of interactive teaching may be preferred to others. For example, personal experience from Project SMART revealed that role-plays about peer pressure often had unintended effects. That is, role-players failed to resist pressure convincingly, and individuals assigned to play offerers often stole the show (Hansen, Graham, et al. 1988).

Experience has also shown that Socratic discussions, while potentially highly interactive and involving, can result in undesired conclusions. Interactive teaching that is likely to succeed might well be thought of as any method that has the ability to engage participants in the active consideration of appropriate program materials, whether it be to develop skills or ensure active cognitive processing.

It is likely that the only way for programs to achieve changes in mediating targeted characteristics is to require introspection within the self and observable "real" behaviors and attitudes within the peer group. Noninteractive techniques provide little motivation or opportunity for either of these to occur.

One way interactive methods work is by requiring the individual to place personal perceptions and beliefs in the open for examination by others. For example, norm-changing programs require students to understand what others do and how others feel. Such approaches require that students reveal personal information. Interactive methods often involve structured conflict that may also bring emotional reactions from participants. In such circumstances, interactive methods are much more likely to foster introspection and the critical examination of the attitudes, beliefs, and behaviors of others. Interaction, by definition, is a performance variable. No matter how it is defined in a written curriculum, if interaction does not emerge in the classroom, interaction does not exist. There has been concern about teacher preparedness to engage in interactive methods (Bosworth and Sailes 1993). In such circumstances, interactive techniques are of unknown potential benefit. Thus, although interactive methods are the only methods for which program success is apparent, interaction remains a challenge.

Finally, interaction alone is not expected to be a sufficient condition for prevention. Effective programs are interactive, but not all interactive programs will be effective. Programs that are highly involving for students but do not address the changing drug-related characteristics of students are not expected to be any more effective than programs that are not interactive.


Evaluation

To be successful, programs must demonstrate lower rates of substance use onset among students receiving the program than among students not receiving the program. Evaluation is crucial to the achievement of prevention effectiveness, although many programs are defended on the basis of testimonials and subjective evaluations. Improving effectiveness goes hand-in-hand with critical program evaluation. This is true for several reasons. First, evaluation achieves a focus on end points that cannot be developed any other way. Second, evaluation provides information that can be actively incorporated into programming to guide program development and improvement. Finally, without evaluation evidence, the ultimate effectiveness of a program simply cannot be known. Claims of effectiveness without data have proven misleading in the past and have contributed to the reemergence of drug use.

When the Omnibus Anti-Drug Act was passed, the technical capability for program evaluation existed. But the technology for conducting evaluations was not disseminated broadly, and there was a lack of political interest in doing such evaluations. During the past decade, at least three surveys (American Drug and Alcohol Survey from the Rocky Mountain Behavioral Science Institute, the Pride Survey from PRIDE, and the Youth Risk Behavior Survey from the Centers for Disease Control) have become available to schools. These surveys provide valuable information that can be used for tracking drug use and mediating variables. In addition, several States have recently adopted Statewide needs assessment surveys, often collected through the schools.

Many of these surveys contain information that could be used in evaluation studies. Because the prevalence of drug use increases among students as they grow older, evaluations that do not include appropriate comparison groups will appear to demonstrate only that drug use is increasing. Several reasonable possibilities exist, including (1) comparing program groups with highly similar groups (in terms of ethnicity, age, socioeconomic status, and risk for drug use) not yet exposed to the program; (2) comparing different age groups at the same outcome point, for example, comparing an entire grade of students who received a program with an entire grade of students who did not receive the program but at the same end point (e.g., ninth grade) (McNeal and Hansen 1995); and (3) comparing data about program groups that have known preprogram similarity with national data. The technology required to complete evaluation studies is clearly within reach of most social scientists. Several groups that offer commercial surveys are also capable of providing evaluation comparisons.

A consistent recommendation is to adopt programs that have previously been evaluated elsewhere. Although the adoption of programs that have been empirically validated would clearly be an improvement over current practice, several caveats about such strategies should also be kept in mind. Society and the research base are constantly changing. Published program evaluations that address behavioral outcomes typically involve a delay of 4 to 5 years. Dissemination and interest in findings may add another 2 to 3 years. Simply adopting a program that can pass a strict litmus test of effectiveness may keep schools from ever having an effective program. Many of the evaluations in the literature that show promise today were completed by the same group that developed the program being evaluated. It is inevitable that some biases, either in program implementation or in the selection of findings to report, exist in this literature.

Finally, many of the programs recently reviewed and given high ratings by Falco (1996) are either old or not commercially available. In the end, the capability of conducting local evaluations may be as viable as adopting programs shown to be promising through external evaluations.


Training and Support

The potential effectiveness of any prevention program is only as great as the person delivering the program. Bosworth and Sailes (1993) note that the teaching techniques used in the most promising prevention programs are often a challenge for teachers to implement. Programs are complex and may not provide sufficient written background for teachers to use without training. Furthermore, with programs increasingly relying on both theory- and data-based rationales for development, it is important to understand the concepts of the programs.

Teaching has a long tradition of reinvention, and teachers will interpret new materials from within their existing framework. The promising programs may involve a program focus and teaching style that is radically different from a teacher's existing paradigm. Instead of focusing on knowledge acquisition (the primary paradigm of teaching), promising programs focus on socialization, psychological dissonance, and emotion-laden topics and methods.

Early success in program delivery appears to be an important determinant of ultimate maintenance of prevention programs. Teachers who find delivering a program too difficult may quickly abandon further efforts. Flannery and Torquati (1993) failed to find any relationship between school principal support and teacher participation in training, but did find that satisfaction with the program was a major determinant of program continuance. Rohrbach and colleagues (1993) found that teachers who maintained a psychosocial prevention program beyond the first year were those who had higher self-efficacy, enthusiasm, preparedness, teaching methods compatibility, and support from their school principals.

Gingiss (1992) concludes that improving program implementation and maintenance is highly related to teacher training: (1) Teachers respond to innovations in developmental stages; (2) a multiphase approach to staff development is needed to help teachers through each stage; (3) continuing training is important (preservice training is insufficient); (4) approaches to training should fit the skill levels of teachers; and (5) teacher training should be conducted in a manner that allows training and the implementation of the program to maintain high visibility, credibility, and value.

In support of the last recommendation, Parcel and coworkers (1988) postulate that institutional commitment, changes in policies, and establishment of appropriate roles may be prerequisites to the successful adoption of innovative programs. This may include the identification of specialists who take on different roles within the school in delivering prevention programs. It may also require active participation by teachers in making decisions about program adoption (Parcel et al. 1991; Paulussen et al. 1994). For example, some research (Perhats et al. 1996) suggests that teachers and parents are much more sensitive to the potential effectiveness of prevention programs than are principals, school board members, and administrative specialists.

There has been little research on the potential for such strategies as continuing education to help improve teachers' motivation, understanding, and self-efficacy. However, continuing education is the primary source of post-inservice training that is available in most school districts.


Conclusion

The field of prevention has made significant progress. Science-based programs now have the potential to significantly reduce or, at a minimum, deter the onset of drug use among youth. Programs that focus on data-driven content that is theoretically informed have increased the potential strength of programming. These programs are highly interactive. They require training and support to be delivered effectively. In all cases, programs benefit from the adoption of evaluation methods that have the potential to document success and inform about failure. Local evaluation will be increasingly important in understanding the potential for programs to be effective.


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