ASSESSING THE EFFECTS
OF SCHOOL-BASED DRUG EDUCATION:
A SIX-YEAR MULTI-LEVEL ANALYSIS
OF PROJECT D.A.R.E.

by Dennis P. Rosenbaum, Ph.D. Professor and Head
and Gordon S. Hanson, Ph.D. Research Associate
Department of Criminal Justice and
Center for Research in Law and Justice
University of Illinois at Chicago
April 6, 1998

News story on the release of this report. Comments from the author.

Abstract | The DARE Program | DARE Curriculum | Previous Evaluations | Methodology | Analysis Strategy | Effects of DARE | Summary & Conclusions | References | Notes

This manuscript is under review for publication and should not be quoted without the permission of the senior author. This research was supported by a grant from the Illinois State Police. Points of view expressed are those of the authors and do not necessarily represent those of the funding agency. Inquires about this research should be addressed to Dr. Dennis P. Rosenbaurn, Professor and Head, Department of Criminal Justice, University of Illinois at Chicago. 1007 W. Harrison, Chicago, IL 60607.

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ABSTRACT

A randomized longitudinal field experiment was conducted to estimate the short- and long-term effects of the Drug Abuse Resistance Education program (D.A.R.E.) on students’ attitudes, beliefs, social skills, and drug use behaviors. Students from urban, suburban, and rural schools (N=1798) were followed for more than six years, with surveys administered each year horn 6th through 12th grades. Teachers were also surveyed annually to measure students’ cumulative exposure to supplemental (post-D.A.R.E.) drug education. Multi-level analyses (random-effects ordinal regression) were conducted on seven waves of post-treatment data. The results indicate that D.A.R.E. had no long-term effects on a wide range of drug use measures, nor did it show a lasting impact on hypothesized mediating variables, with one exception. Previously documented short-terms effects had dissipated by the conclusion of the study. D.A.R.E., although ineffective by itself over the long haul, appears to inoculate students against the apparent negative aspects of supplemental drug education. Some D.A.R.E.-by-Community interactions were observed: urban and rural communities showed some benefits, while suburban areas experienced small adverse effects from participation.

Drug Abuse Resistance Education (D.A.R.E.) is the nation’s most popular school-based drug education program it is administered in approximately 70% of the nation’s school districts, reaching 25 million students in 1996, and has been adopted in 44 foreign countries (Law Enforcement News 1996). Its effectiveness in combating drug usage, however, has been a matter of bitter controversy, and this debate is taking place in the context of rising drug use among our nation’s youth. After experiencing large declines in drug use in the 1980s, the national trend began to reverse in the early 1990s: the percentage of high school seniors who reported using illegal drugs "during the past year" increased from 22 percent in 1992 to 35 percent in 1995 – a 59 percent increase (Johnston et al. 1996). Marijuana is one drug where dramatic increases were observed. The number of eighth graders who reported using marijuana during their lifetime jumped from 10.2 percent in 1991 to 19.9 percent in 1995 – a 92 percent increase. Reports from the Office of National Drug Control Policy (1997) reflect a growing concern about recent trends in drug-use attitudes and behaviors among America’s youth, and call upon the nation to act swiftly to prevent a future drug epidemic.

This growing drug problem has caused a flurry of media coverage and political finger pointing, a11 leading to closer scrutiny of our nation’s efforts to control and prevent drug abuse. The spotlight has been especially strong on America’s most popular and visible program-D.A.R.E. Whether or not D.A.R.E. has been an effective preventive program has been the subject of considerable debate and research. The publication of a national study that questioned the effectiveness of D.A.R.E. in preventing drug use (Ringwalt et al. 1994) opened the door to an avalanche of criticism in the popular press. A Washington Times article in 1996 declared that -D.A.R.E.’s success...is a political illusion. based on massive publicity efforts and a contempt for results" (Bovard 1996).¹ A prominent police chief characterized D.A.R.E. as "enormously popular" yet an "enormous failure," and hence, decided to drop the program because "it does not work" (NBC Dateline 1997). Of course, the problem of demonstrating effectiveness in drug prevention is not unique to D.A.R.E. Several literature reviews and meta-analyses of school-based drug prevention programs have concluded that most are ineffective in preventing drug use (see Battjes 1985; Bangert-Drowns 1988; Botvin 1990; Bruvold and Rundall 1988; Ennett et al. 1994; Hansen 1990; Ringwalt et al 1994; Tobler 1986).

The latest pressure on school-based drug education programs comes from federal legislation. Congress enacted the Drug-Free Schools and Communities Act in 1987 (and many subsequent amendments) to beef-up our nation’s drug education and prevention programs. Effective July 1, ) 998, local school districts will be expected, for the first time, to provide evidence of program effectiveness in order to receive federal Title IV funds. Funding is widely available for "research-based" strategies that are consistent with the new "Principles of Effectiveness." One of the core principals is that "..grant recipients shall...select and implement programs that have demonstrated that they can be effective in preventing or reducing drug use, violence, or disruptive behavior." ² The new SDFSCA language will force many states, school districts, and schools to give more attention to drug education goals, processes, and evaluation results. If proposed school-based programs are taken at face value, their main goal is clear – to prevent drug use among the target population. Whether programs can achieve this goal is an empirical question that should answered, in part, through rigorous evaluation research.

The present article reports on a comprehensive longitudinal evaluation of D.A.R.E. that occurred between 1989 and 1996 in the State of Illinois. This paper includes the anal analyses of the full data set collected as part of the Illinois D.A.R.E. study, which tracked students ham 5th and 6th grades through’ their junior and senior years of high school.

The D.A.R.E. Program

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D.A.R.E. is a series of school-based drug and violence prevention programs for kids in Kindergarten through 12th grade. It is a cooperative venture between law enforcement agencies, schools, and the local community, and it involves the use of trained, uniformed police officers in the classroom to teach a carefully planned drug prevention curriculum. Created in 1983 as a collaborative venture between the Los Angeles Police Department and the Los Angeles United School District, D.A.R.E. has expanded to become the largest drug education initiative in the world. The core D.A.R.E. curriculum, which is the subject of this research, focuses on children in their last year of elementary school (5th or 6th grade). It is based on the assumption that students at this age are the most receptive to anti-drug messages as they approach the age of drug experimentation.

Theoretical Framework

Evaluations of D.A.R.E.’s effectiveness as a public policy can also be viewed as a test of its theoretical underpinnings. Although some researchers have referred to D.A.R.E. as "atheoretical" (Winfree, Esbensen, and Osgood 1996), this is far from accurate. Unlike the earlier generation of drug education programs in the 1970s, D.A.R.E. is solidly grounded in a body of theory and research that laid the foundation for a second generation of school-based prevention initiatives. The program is deeply rooted in the social skills and social influence model of drug education. As Botvin (1990) notes, a variety of strategies can be characterized as part of this "psychosocial" approach to drug prevention, but three general categories of programs can be identified: psychological inoculation, resistance skills training, and personal and social skills training. D.A.R.E. has elements of each approach in its curriculum.

Botvin compares psychological inoculation to "traditional preventive medicine" in that individuals are exposed to weak doses of "infection" so that "anti-bodies" may be developed. (D.A.R.E.’s "vaccine" takes the form of simulated temptations and pressures to use drugs). The resistance skills training approach places emphasis on teaching specific skills for evading or resisting these "negative social influences," including subtle media influences (D.A.R.E. students engage in role playing scenarios to resist peer offers of drug use). The personal and social skills training approach is not problem-specific, but more broadly oriented to the "acquisition of generic personal and social skills." These will have the incidental effect of preventing the development of socially learned behaviors and attitudes that are believed to be associated with substance use. Recent applications of the personal and social skills approach were modeled after earlier interventions shown to be effective in preventing cigarette smoking (Flay et al 1983). Some successful applications of this model to drug abuse have been reported in the literature (Botvin 1990; Clayton et al 1991; Flay 1985; Hansen 1992; Tobler 1986). Particular attention is given to helping youth develop the social skills to recognize and respond appropriately to peer pressure.

From the outline of the curriculum (see Table 1), it is apparent that D.A.R.E. also includes what Botvin (1990) calls "information dissemination" and "affective education." The former is designed to provide students with enough knowledge to make informed cost-benefit decisions about drug use (e.g. D.A.R.E. includes information on drug use, misuse, and consequences; media influences; drug use alternatives). The latter is similar to the "personal and social skills" approach, but is focused on a strategy of "social enrichment." D.A.R.E. attempts to do this by focusing the curriculum on self-esteem building, managing stress. decision-making, role modeling, and forming support systems. The general hypothesis implicit in the D.A.R.E. model is that classroom instruction by trained police officers will result in enhanced self esteem, self-understanding, and assertiveness, a clearer sense of values, and more responsible decision-making habits, which, in turn, should make students less vulnerable to the enticements and pressures to use drugs and alcohol.

Table 1

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Original D.A.R.E. Curriculum

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Previous D.A.R.E. Evaluations

There have been many outcome evaluations of the core D.A.R.E. curriculum, but the methodological rigor of these assessments vary considerably.³ Most of these studies are of limited scientific value because of their weak research designs, poor sampling and data collection procedures, inadequate measurement, and analysis problems. Indeed, the boldest claims of D.A.R.E.’s success are especially vulnerable to such criticism given rampant problems with internal validity. Most evaluations have been Posttest-Only designs, i.e., the survey instrument is administered for the first time after students have participated in the program. Some of these Ex Post Facto evaluations did not include any type of control group (Aniskiewicz and Wysong 1987; Carstens et al. 1989; Correll 1990; McMahon and Wuorenma 1992; Netburn 1989; Silva 1995). Other studies required the respondents to recall, retrospectively, whether or not they had received D.A.R.E. (De Jong 1987; Donnermeyer 1998; Dukes et al. 1996; Dukes et al 1997; Fife 1994; Wysong et al. 1994), or they used a non-equivalent control group (McDonald et al. 1990). Many of these evaluations reached conclusions that were favorable to D.A.R.E.,⁴ some on the basis of responses to as few as Ave survey items. The limitations of these studies are too numerous to be listed here, but clearly, the observed differences may be the result of self-selection processes (or other pre-existing differences) rather than the D.A.R.E, program (see Cook and Campbell 1979, 98).⁵

There have been several D.A.R.E. evaluations that could be classified as "quasi-experimental." Three used pretest-posttest designs without a control group (Anonymous 1987; Kethineni et al. 1991; Wiegand 1991), and two of those were also flawed by survey instruments of the type used in the weakest of the Ex Post Facto evaluations. A larger number of quasi-experimental evaluations (Reeker et al. 1992; C1ayton 1987; Etheridge and Hicks 1989; Faine and Bohlander 1988; Faine and Bohlander 1989; Harmon 1993; McCormick and McCormick 1992; Manos et al. 1986; WaIker 1990) have sufficient scientific integrity to allow estimates of causal effects. These quasi-experimental studies produced more modest assessments of D.A.R.E. than the weaker evaluations. They uncovered fairly consistent short-term effects of D.A.R.E. on mediating variables such as knowledge, attitudes, and social skills (Reeker et al. 1992; Clayton 1987; Faine and Bohlander 1989), but provided little evidence of D.A.R.E.’s impact on drug use behaviors.

The strongest design used to assess D.A.R.E. (with the fewest threats to validity) is the randomized experiment. Only a fever evaluations have employed experimental designs with sufficiently large sample sizes and repeated measurement over one or more years (Clayton et aL 1991a; Clayton et al 1991b; Clayton et aL 1996; Ennett et al 1994; Lindstrom 1996; Ringwa1t et al. 1990; Ringwalt et al 1991; Rosenbaum et al. 1994). These studies clearly indicate that D.A.R.E. s positive effects on students tend to dissipate over time. D.A.R.E. has its largest short-term benefits on students’ knowledge about drugs, but statistically significant positive effects have also been observed for social skills, drug-related attitudes, attitudes toward the police and, less frequently, self-esteem The effects on drug use behaviors are often small and nonsignificant, although significant short-term reductions in tobacco use have been noted on more than one occasion (see meta-analysis by Ennett et al. 1994). The literature of D.A.R.E.’s effectiveness as a drug prevention strategy can be summarized in this way: the stronger the research design, the less impact researchers have reported on drug use measures.

One of the major limitations of even the best D.A.R.E. evaluations is the short lag between pre-test and post-tests. Despite the growth in the number of D.A.R.E. studies, surprisingly few are longitudinal in nature. Most of the stronger studies have examined program effects immediately after students participated in D.A.R.E. (Becker et al. 1992; Faine and Bohlander 1988; Harmon 1993; Kethineni et al. 1991; Lindstrom 1996; Manos et al. 1986; Ringwalt et al. 1990; Ringwalt et al. 1991; Wa3cer 1990); a few have looked at one-year and two-year outcomes (Clayton et aL 1991a; Clayton et al. 1991b; Ennett et al. 1994; Rosenbaum et aL 1994). Given the relatively low base rates for drug use at the ages of 11 or 12 (when D.A.R.E. is introduced), short time lags between pretest and posttest measurement can severely restrict the opportunity to detect preventive effects.

Figure 1 captures the essence of this problem: most of the students in the present study entered high school at wave 5 of the survey. This is the point at which marijuana use within the past 30 days, for example, begins to rise dramatically, from 2.5% of those surveyed at wave 4 to more than 25/a at wave 8. D.A.R.E. is typically administered in sixth grade, well in advance of the steep rise in usage patterns common to most substances. Thus, a real test of program effectiveness must extend to the age group where opportunities for drug use are substantial; otherwise there will be a ceiling or upper limit on the dependent variable.

Prior D.A.R.E. research has virtually ignored the possible effects of supplemental (i.e. post-D.A.R.E.) drug education during the middle school and high school years. School-based drug prevention is now mandatory in many states, including Illinois where this study was conducted. This post-D.A.R.E. instruction could have the effect of contaminating the control group and confounding the effects of the treatment. Also, D.A.R.E. may be more or less effective in combination with other drug education initiatives.

The national study by Silvia and Thorne (1997) found that students were exposed to a wide range of drug prevention p*rograms at a11 grade levels and that these programs were delivered inconsistently with wide variability. One state-wide study (Donnermeyer 1998) reports evidence of a cumulative "booster effect," i.e., students who participated in multiple drug use prevention activities reported less drug use than students who reported less exposure to school-based activities. Unfortunately, this study is a one-shot cross-sectional design⁶ that suffers from numerous threats to validity, including self-selection at the individual and school levels. Rather than rely on students’ recall, which is vulnerable to considerable memory decay, the present study measures their exposure to supplemental drug education by interviewing their teachers on an annual basis.

Finally, previous D.A.R.E. evaluations have been plagued by a variety of data analytic problems, ranging tom improper use of statistical tests to a failure to use covariates or control variables in the analysis. Even the strongest D.A.R.E. evaluations typically suffer from the problem of treating individuals as the only unit of analysis when in fact students are "nested" within specific schools. Statistically-minded critics have argued that evaluations of school-based programs fail to consider school-level effects in the analysis of data collected from individual students, a mistake which can lead to overly-liberal estimates of program effects (Murray and Hannan, 1990). The current study corrects this problem through the use of multi-level analyses.

Earlier Findings From This Longitudinal Study

In both published and unpublished technical reports, we have reported the effectiveness of this program at various measurement points. Given that the literature contains only one other long-term study of D.A.R.E., we believe it is important to summarize the earlier findings here.

Drug use outcomes.

Immediately after graduation from the D.A.R.E. program, students m the experimental group reported a significant decline in recent (30-day) use of cigarettes relative to the control group, but no other changes were observed on a wide range of drug and alcohol behavior measures. Follow-up studies conducted one, two, and three years after the program found that D.A.R.E. had no maim effects on any of the drug and alcohol measures.⁷ After four years, some new drug use measures were added (considered inappropriate for younger students) and we found that D.A.R.E. students were significantly older when they "first got drunk" and when they started ‘ drinking "at least once a month." These delayed-onset effects, however, were not sustained at the 5-year measurement point. In fact, after five years, the program was associated with unexpected adverse effects on the primary drug outcomes; that is, D.A.R.E. students, relative to controls, reported significantly higher scores on the Total Drug Use and Total Alcohol Use indices, as well as the severity of

Mediating variables.

The presence of D.A.R.E. was associated with a number of hypothesized changes in attitudes, beliefs, and social skills. At the immediate posttest, significant gains were observed on seven outcome measures. Students exposed to D.A.R.E. (in comparison to those in the control group) acre more likely to report negative attitudes toward drugs in general, negative peer attitudes toward drugs, greater awareness of media influences concerning beer (and cigarettes), positive changes in self-esteem, greater assertiveness in social situations, and positive attitudes toward the police. Over time, however, the effects of D.A.R.E. on attitudinal and psychological variables declined. After one year, the effects on self-esteem, assertiveness, and attitudes toward the police had dissipated. Four attitudinal effects continued after two years, but after three years, a11 such effects were gone with one exception: D.A.R.E. students continued to feel more confident in their ability to resist peer pressure. After four years, however, all effects relevant to attitudes, beliefs, and social skills were gone.

Academic and school behavior.

Overall, with a few subgroup exceptions, D.A.R.E. had no effect on self-reported grades, the number of times students were in trouble with teachers, the number of times they skipped class, or the frequency of their involvement in delinquent or criminal activities.

The present article employs the entire 6-year data set to estimate the effects of D.A.R.E. on students attitudes, beliefs, social skills, and behaviors. To date, the rests of this longitudinal study suggest that the effects of D.A.R.E. have waned over time. Some conflicting endings across the years may be due to interactions between program and maturational effects or may be due to slight improvements in the measurement and analytic procedures that were introduced by the researchers. Hence, the complete data set is used here to test the fundamental hypothesis that D.A.R.E. had a significant overall effect on theory-based and program-based outcomes. This study is not a wave-by-wave analysis (as previously completed), but rather addresses the basic question of whether, in the Goal analysis, students who participated in D.A.R.E. are different than students in the control group ashen all posttest test are analyzed.

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METHODOLOGY

The Illinois D.A.R.E. Evaluation was conducted as a randomized field experiment with one pretest and multiple planned post-tests. The researchers identified 18 pairs of elementary schools, representative of urban, suburban, and rural areas throughout northern and central Illinois. Schools were matched in each pair by type, ethnic composition, number of students with limited English proficiency, and the percent of students from low income families.⁸ None of these schools had previously received D.A.R.E.. For the 12 pairs of schools located in urban and suburban areas, one school in each pair was randomly assigned to receive D.A.R.E. in the spring of 199Q; the remainder were placed in the control group. For each of the remaining six pairs, all m rural communities, a non-random assignment process was necessary due to logistic considerations that affect the availability of D.A.R.E. officers. The remaining 6 "treatment" schools were selected from rural areas in which D.A.R.E. officers were already assigned, and 6 more control schools were then selected from nearby counties. The same matching variables were employed for all schools m the study.

Two types of surveys were administered each year over the six years of data collection: one for students and one for specific teachers. The purpose of the student survey was to determine D.A.R.E.’s overall effects on students’ beliefs, attitudes, and behaviors related to drug use. The student survey data are the p focus of this longitudinal evaluation. The teacher survey provided supplemental information to assess the extent of students’ exposure to post-D.A.R.E. drug prevention programs during each current academic year.

Recruitment of Schools and Students

Two waves of data (pre-post) were collected from the thirty-six (36) schools m the first year (1989-1990). In the second year (wave 3, 1991), when students left these elementary schools and entered middle school, the recruitment process was repeated with approximately 150 schools. In the third year and beyond, as students continued to move, transfer, and graduate, the number of schools in the sample fluctuated between 150 and 300. For the 1992-93 academic year, most of the evaluation sample entered high school for the first time, which required the research team to develop relationships with an entirely new group of school officials.

Similar to the initial procedure, letters were mailed to all high school superintendents and principals horn the existing sample of schools, informing them of students prior participation in the study, seeking their cooperation, requesting verification of enrollment, and explaining the research procedures. With a11 the transience in the sample, the research staff was continually making contacts with representatives from new schools. A financial inducement to participate in the study was offered to major schools, depending on the number of students participating from their school and the level of cooperation obtained.

In each school, eligible students were those who had participated in the Wave I survey in 1990. Passive consent procedures (to obtain parental permission) were approved by the Institutional Review Board of the University of Illinois at Chicago. Consent forms were mailed to parents in January of 1990 requesting their child’s participation for three academic years. The letter informed parents of the purpose and content of the project, stressed the confidentiality of the information to be collected⁹ and invited parents to return the form in a stamped envelope if they did not wish their child to participate. During the fall of 1993, a new consent letter was distributed to parents by mail or through the school, requesting their consent for the final three years of the study.

Changes in the Evaluation

Two issues emerged in the drug education literature during the course of this evaluation. First, there was the possible "contaminating" influence of students being exposed to additional drug education programs in the years following their participation in D.A.R.E.. Evaluators inevitably face "multiple treatment interference" (Cook and Campbell 1979) as they attempt to estimate the effects of D.A.R.E. in the context of subjects’ exposure to other types of drug education.¹⁰ With the rapid growth of drug education in recent years (including the enactment of legislation requiring that schools teach drug education), students in both the experimental (D.A.R.E.) group and the control group were frequently given some additional drug prevention education in subsequent years. To the extent that these supplemental programs had some favorable impact on students they may have equalized the two groups on drug-related outcomes, and therefore, biased the evaluation findings in favor of the nu11 hypothesis (i.e. increase the likelihood of finding no difference between the experimental and control groups). The reverse outcome is also possible. Researchers have lamented this problem in the literature, but have rarely taken steps to measure or control for the effects of this "contamination." In contrast, the Illinois evaluation gave additional attention to this issue. With additional survey work, we were able to develop a cumulative index of a student’s exposure to supplemental drug education programs over several years. This measure also allowed us to test the "booster" hypothesis, namely, that additional drug education programs at the middle and high school levels will boost or reinforce the anti-drug messages and skills received in the D.A.R.E. program, and that this consistent reinforcement will make a difference in drug use behaviors during the years of greatest opportunity and pressure.

A second issue concerns the proper approach to data analysis. As noted earlier, statisticians now recommend that school-level effects be assessed when analyzing data collected from students representing multiple school settings. There is noir considerable support for this argument among statisticians and other methodologists, who have developed new statistical programs for conducting multi-level analysis (e.g. Hedeker and Gibbons 1993). Furthermore, a time-Game that carries well beyond the "nesting" of students in their original elementary schools, and involves a multi-wave posttest analysis, is more likely to need some means of controlling for the difference between students who have been surveyed at all waves, and those who dropped out or were absent at one or more waves.

Multi-level analysis software such as Hedeker’s MIXOR and MIXREG have been developed in part to control for the attrition-related effects of being in the experimental or control group. Differential attrition may inflate or debate estimates of program effectiveness. The results of logistic regression analysis indicate that attrition in the present data set was more likely among: students in the control group, students from single-parent families, African-Americans, Hispanic, urban students, and males. However, an Analysis of Variance found no support for the hypothesis that the subjects experimental condition (0,1) interacted with attrition status (0,1) to influence any of the four major drug use measures (defined below). More importantly, we used a mixed-level analysis strategy that controls for violations of the assumption of random variance and accounts for both individual differences and clustering within schools (see details in results section). This strategy incorporates the above-named variables as covariates in the regression equation.

Description of Student Instrument

The effects of D.A.R.E. were assessed with multiple mediating and outcome measures. The reliability and validity of these measures have been established in previous research and only slight modifications were made in the present investigation. The following measures were employed:

Drug Use Behaviors.

Students were asked two sets of questions about their use of various drugs, including tobacco, alcohol, and other substances. The format for these questions was originally devised by Moskowitz and his colleagues (1981) for their "Drug and Alcohol Survey." Students indicated whether they had used these substances in "their whole life" and "during the last month (30 days)." Students were instructed not to count the legitimate use of substances, either for religious services (i.e., wine) or because they were prescribed by a doctor (e.g. Librium, codeine). A composite Alcohol Use Index was constructed from measures of four different types of alcohol: beer, wine, wine coolers, and hard liquor. For the 30-day Alcohol Use Index, a value of "1" indicated that the student had used one of four different types of alcoholic beverage during the past 30 days; a value of "2" indicated use of two or more. A 30-day Total Drug Use Index was a combination of students’ responses to 11 different types of drugs and alcohol questions. (In addition to the 4 alcohol measures, this index included smokeless tobacco, marijuana, inhalants, hallucinogens, cocaine, "other drugs," and "alcohol to get "). For the 30-day Total indices, a value of "1" indicated that the student had admitted to one or two types of drug use during the past month, while "2" indicated three or more. Similarly, the lifetime measures were scored as continuous variables with ranges from 1 to 4 for Alcoho1 Use and 1 to 11 for Total Drug Use.

Onset of alcohol use.

To measure the onset of alcohol use, students were asked to indicate how old they were when they "first got drunk or very high using alcohol" They also reported how old they were when they began to drink "at least one drink at )east once a month."

General attitudes toward drugs.

Students indicated their level of agreement with 8 statements concerning drug use, which Moskowitz et al (1981) originally developed for the "Drug and Alcohol Survey." After reversing the scores of positively worded items, a scale was computed by summing student responses, so that a high score represented a positive attitude toward drugs (Alpha Range = .78-.89).

Attitudes toward the use of specific drugs.

These questions, also extracted from the "Drug and Alcohol Survey, " assess specific attitudes toward those substances youth are most likely to use. We grouped together (i.e., summed) student responses to questions concerning their attitudes toward beer, wine coolers, and wine. A higher score on this scale indicates a more positive attitude toward alcohol use (Alpha Range = .82-.90).

Perceived benefits and costs of using drugs.

Students were asked eight questions about their perceptions concerning the benefits, and five concerning the costs of smoking cigarettes and drinking beer and wine coolers (Moskowitz et al. 1981). By adding student responses four indices were created to assess the perceived costs and benefits of using cigarettes and alcohol. A higher score indicates the undesired outcome of lower perceived costs and higher perceived benefits of drug use (Alpha Range = .82-.86, .86-.90; .81-.86, .86-.90).

Perceptions of the media’s influences on smoking and beer drinking.

These two constructs were measured by totaling student responses to questions about media influences on beer drinking and cigarette smoking (Bauman 1985). Students indicated what they thought (1) television and (2) newspapers and magazines made beer drinking and cigarette smoking "look like." Students who responded that the media made substance use look like "both a good and a bad thing to do," or "neither a good nor a bad thing to do, " were scored as a neutral intermediate category between those who thought it was a "good" and a "bad" thing to do. A higher score indicates less student recognition of media attempts to make drugs look attractive (Alpha Range = .79-.82; .79-.85).

Self-esteem.

This construct was measured by adding six items extracted from the Rosenberg (1965) self-esteem scale, which was developed for use with adolescents. Questions were modified slightly to make the language more appropriate for contemporary students. A higher score indicates higher self-esteem (Alpha Range = .80-.88).

Attitudes toward police.

Students rated five items extracted from the "Attitudes Toward Police" scale developed By Faine and Bohlander (1989). The items were then summed, with a higher score indicating more favorable attitudes toward the police (Alpha Range = .84-.90).

Peer Resistance Skills.

Students responded to four hypothetical situations in which either their best fiend or an acquaintance offered them either cigarettes or alcohol (Hansen, 1989). They then rated their ability to "say no" on a four-point scale ranging from "not sure at all" to "very sure." The four items were summed, with a higher score indicating greater confidence in ones ability to resist peer pressure to use substances (Alpha Range = .86-.90).

School Performance.

Self-reported grades were used as a measure of school performance. The range was &am 1 to 8, from less than D’s (coded as 1) to mostly A’s (coded as 8). A separate component of this study conducted at wave 4 revealed that self-reported grades were a good reflection of official grades (i.e., the correlation coefficient between the two was 0.60). · Delinquent and Violent Behavior. A multi-item index was created to measure students’ involvement in delinquent behaviors. Several of these items are derived from the High School Senior Survey conducted by the University of Michigan (Johnston et al., 1988). Behaviors include group violence, theft of property under $50, theft of property over $50, shoplifting, and damage to school property. Participation in a group fight (involving one group or gang against another) was also treated as a separate measure of violence. RESULTS

Characteristics of the Student Sample

The results reported here are based on the combined sample of students surveyed at all waves. The wave-by-wave characteristics are shown in Table 2.

Table 2

Characteristics of Students1 - All Waves

1Figures are percentages

Approximately two-thirds of the students were in sixth grade at the time of wave 1 data collection (with the remainder m fifth grade). Roughly 6-m-10 students indicated that they were living with both parents in the same household at all waves. Slightly more than half (52%) were exposed to D.A.R.E. m the spring of 199Q, while the remaking students were part of the control group. Attrition over the six years was most noticeable among the urban and African-American samples.

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Analysis Strategy

We employed a random-effects ordinal regression model that allowed us to examine the relationship between D.A.R.E. and individual-level outcomes while controlling for random effects. We used the MIXOR and MIXREG programs, developed at the University of Illinois at Chicago by Donald Hedeker and his colleagues. The program uses maximum marginal likelihood solution and is applicable to both probit and logistic response functions (see Hedeker & Gibbons, 1993; Hedeker. Gibbons, k Davis. 1991). Maximum marginal likelihood regression was used within the framework of multi-level analysis. Each substantive model included an indicator for whether the student had received D.A.R.E., plus a set of binary-coded control variables that included race/ethnicity, gender, family structure (intact vs. non-intact), and metropolitan status (urban, suburban, or rural).

Merging Waves. Data from the seven post-test surveys were merged. The analysis strategy involved a level and trend comparison of the D.A.R.E. and control groups across all post-test waves. Cases were sorted by student identification number so that there would be up to 7 observations per student, with each observation representing a different wave of post-test data.

Before adding each wave to the composite data set, a "Time" variable was created, with all of the observations for a particular wave receiving the same Time value. After merging the seven post-test waves, the Time variable was recoded so that wave 2 was Time 0, wave 3 was Time 1, and so on up to wave 8, or Time 6. The Time variable was the basis for determining the existence of significant changes m attitudes or drug usage over time, and of controlling for this trend in the comparison of D.A.R.E. group and contro) group responses. The basic model for all attitude measures, and for the delinquency index, can be simply expressed as...

Y=b0+b1Time+b2D.A.R.E.+b3(D.A.R.E)*Time)+demographic area covariates

...where Y is the scale mean, b, is the wave 2 or Time 0 mean, controlling for the

demographic and area covariates, b, is the rate of change per wave or year, b, is the effect of D.A.R.E. on the wave 2 or Time 0 mean, and b, is the effect of D.A.R.E. on the rate of change per wave or year. D.A.R.E. is equal to 0 or 1, where 0 = control group and 1= D.A.R.E. group. When D.A.R.E. is 0, all terms in the equation containing D.A.R.E. become 0. For analyses where the dependent variable was some type of alcohol and total substance use, a binary variable for high school years (grades 9 through 12) was added and interacted with Time in the same manner as the D.A.R.E. variable. The high school variable was added to control for the dramatic increases in drug usage during those years.

In order to test for differential effects on female, African-American, and Hispanic students, these demographic covariates were interacted with D.A.R.E. and added to a second model. The area covariates were interacted with D.A.R.E. in a third model to test for main effect (b2) differences in rural, urban, and suburban areas. Because of potential problems with multiple interaction terms, these subgroup interaction effects were, for the most part, only estimated in models that did not control for cumulative exposure to supplemental drug education (discussed below).

Exposure to Supplemental Drug Education

At each wave, beginning with wave 3 (one year after exposure to D.A.R.E.), a survey of the "most knowledgeable" local school teacher was conducted to determine the number of hours of additional drug education that students received at their current schools: the number of hours per week was multiplied by the number of weeks of drug education. The cumulative supplemental drug education variable was computed by adding the number of hours at that wave to the number of hours at each preceding wave. To correct for skewness, these figures were then grouped into 5 dosage levels at intervals of 36 cumulative hours, with the exception that the highest level included all students with more than 144 cumulative hours. In separate models, this variable was also interacted with D.A.R.E. to estimate the effect of D.A.R.E. plus supplemental drug education in relation to the effect of supplemental drug education only."¹¹

Recoding

Several attitudinal and drug use scales were skewed, and therefore necessitated recoding prior to the regression analysis. The Delinquency Index and Peer Resistance scales were recoded into 3-point scales (1-3) with roughly equal numbers of cases in each group. Four-point scales were created for Perceived Benefits of Alcohol and Cigarettes, General Attitude Toward Drugs, and Self Esteem Again, the groups were of similar size.

Clustering and Random Variance

A variable representing the 36 original schools was retained for the purpose of estimating the effect of students being "nested" within particular schools at the time of exposure or non-exposure to D.A.R.E. (See Hedger 8c Gibbons, 1993; Murray 8c Hannan, 1990 for a detailed discussion of this issue). It was expected that this

"clustering" effect would have eroded over time, and that the principal violation o f the assumption of constant variance would be subject-specific rather than school-specific. The results of regression analysis at specific time points largely confirmed this expectation. The other time points and all other scales and usage measurements had intraa-cluster correlations below .05, and most were well below that level."¹²

Because of this, student identification numbers became the basis for bi-level analysis. With continuous outcome measures, regressor effects were estimated while controlling for the effect of subject-level variance in the constant term and over time."¹³ The random effects were statistically significant in all models. Hence, controlling for subject-level variance differences across waves was an important analytic contribution to all models used to estimate program effects.

Effects on Hypothesized Mediating Variables

We tested the hypothesis that D.A.R.E. would have a sustained effect on the variables that are assumed to mediate the relationship between drug education and drug use, namely, students’ attitudes, beliefs, and social skills pertaining to drug use. On the whole, the results did not support this hypothesis (see Table 3). When controlling for changes in these variables over time and for changes in cumulative exposure to supplemental drug education, only one significant D.A.R.E. effect remained. Specifically, students who participated in D.A.R.E. were more likely than students in the to report awareness of media efforts to make beer appear attractive. Even here, the D.A.R.E. interaction with Time (.01*, not shown) was significant in the opposite direction, suggesting that the sophistication of the Control group would eventually catch up to the D.A.R.E. group. A11 other D.A.R.E. effects were small and nonsignificant.

Although not posited as a mediating variable, we also examined the impact of D.A.R.E. on violence and delinquency prevention. Our Delinquency Index, which measures incidents of theft, vandalism, and/or participation in group violence, showed change over time in the desired direction, but not as a result of D.A.R.E. A separate analysis of individual and group violence revealed no D.A.R.E. effects. Previous evidence that African-American students reported less group violence after D.A.R.E was no longer statistically significant.

In addition, we examined the hypothesis that D.A.R.E. would be able to improve academic performance. Self-reported grades, on a scale of 1 ("below D") to 8 ("mostly As") were used to measure academic performance. Although the trend was favorable, the overall results did not support this hypothesis. In the face of a significant drop in grades over time (.07 per wave), the D.A.R.E. effect was positive (.09 per wave), but was only significantly higher for rural students (.29*).

A test of the booster hypothesis revealed that exposure to supplemental drug education appears to have been largely counterproductive: each additional 36 hours of cumulative drug education accounted for significantly greater negative attitudes toward police, more positive attitudes toward drugs, alcohol, and cigarettes, and more delinquency (see Table 3). The only favorable outcome was that students’ with more supplemental drug education reported greater awareness of attempted media influences on drug use.

Table 4
D.A.R.E.-by-Supplemental Drug Education (SUE)

Interaction Effects on Attitudes, Beliefs, and Social Skills1

Table 5

Main Effects of D.A.R.E. and Supplemental

Drug Education (SDE) on Drug Use1

Table 6

D.A.R.E.-by-Supplemental Drug Education (SDE)

Interaction Effects on Drug Use1

Table 7

D.A.R.E.-by-Area Interaction Effects on Drug Use1

TABLE 8

D.A.R.E.-by-Supplemental Drug Education (SDE)
Iteraction Effects on Drug Use Likelihoods1