Click for next page ( 77


The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 76
Evaluating Prevention Program Effects As we have seen, the theoretical foundations for prevention are based on three principal approaches: (1) the risk factor approach, implemented mainly in the primary grades to affect predisposing factors; (2) the develop- mental approach, which concentrates on the socially reinforcing properties of classrooms and family environments; and (3) the social learning ap- proach, working in junior high and middle schools mainly to alter enabling factors, such as skills and motivation to resist media and peer influence. All three approaches use the school as the basic vehicle through which prevention efforts flow, although the stronger examples of each type of intervention recognize and seek to make positive use of the fact that schools exist within the context of family and community. There is a related movement toward the use of mass communications media as an educational channel. Much of the theoretical foundation for social influence approaches is transferable to mass media, although commu- nications experts view the media fundamentally as a supplemental or ampli- fying rather than the primary carrier of persuasive communications regard- ing health-related behavior. The empirical research picture is not as tidy as the theoretical concepts. For one thing, differences that are sharp and clear in theoretical abstraction become blurred in the details of application. Most actual school-based prevention curricula, of whatever theoretical inspiration, include a number of the following components: 76

OCR for page 76
EVALUATING PREVENTION PROGRAM EFFECTS 77 Technical information about drugs and the consequences of use, Instruction on techniques for making decisions about drug use, Clarification of values to help put decisions about drug use in per- spective, Instruction in stress management techniques, Exercises to enhance self-esteem, Social learning to enhance self-efficacy, Instruction in setting goals and working to implement them, Life skills training to assist students in resisting drug use, Resistance skills training to help students resist pressures, direct and indirect, to use drugs, Making a pledge publicly not to use drugs, Instruction in how to set norms for one's age-graded peers and self, Instruction in how to provide assistance to one's peers, and Identification of and encouragement to seek alternatives to drug use. . The empirical challenge has been to sort out the critical elements from the adventitious ones, find the best time to begin intervening, select the optimal programmatic sequence and emphasis, identify the most conducive agents of transmission, and divine the most effective ways to prepare those agents for the task. The prevention research field is substantial enough, and of long enough standing, that a number of large-scale, meticulously conducted research evalua- tions of preventive interventions have been completed; numerous research reviews and collections of reviews have been published (see, for example, Goplerud, 1991; Bell and Battjes, 1987; Kumpfer, 19873. Several well- defined prevention programs have been very widely disseminated. But for various reasons, the transitions from publication of major results, to compi- lation of definitive reviews, to wide dissemination of practices have been less than ideal. Indeed, reading the prevention research literature brings to mind the Cheshire cat in Lewis Carroll's Wonderland: lines of work seem to resolve into vivid conclusions, which then fade away in a few critical turns of the page. The will to believe on the part of implementers and program sponsors alike seems stronger than the evidence supports. With this forewarning, we begin the chapter by recounting widely cited recent meta-analyses of research findings on preventive interventions. To give more concrete meaning than we think can yet be gained from these synthetic reviews, we then analyze (1) a series of curricula that use cogni- tive and behavioral approaches in relatively limited-scale experimental in- terventions; (2) completed large-scale experimental studies using social in- fluence programming; (3) prominent work now in progress probing social influence and developmental interventions; and (4) the special role of mass media as channels for prevention communications.

OCR for page 76
78 PREVENTING DRUG ABUSE: WHAT DO WE KNOW? META-ANALYSES OF PREVENTION INTERVENTIONS Meta-analysis refers to techniques developed by behavioral statisticians for quantitatively integrating the findings from various studies. These tech- niques have been described and debated in a number of recent books (e.g., Wachter and Straf, 1990) and widely used in the past decade. As Bangert- Drowns (1988:245), one of the authors reviewed below, points out, meta- analysis has two potentially major advantages over more traditional narra- tive reviews of the scientific literature. First, it adheres to a precisely defined metric of outcome that is comparable across studies: the intervention's effect size, defined as the difference between the average (mean) scores on an outcome measure of the experimental and control groups, divided by their standard deviation. Second, meta-analysis uses reproducible statistical tests to examine relations between effect sizes and characteristics of the studies being reviewed. Two types of meta-analysis have been applied to interventions to pre- vent drug abuse. Tobler (1986) first employed "classic" meta-analysis (Glass et al., 1981~. This method sweeps together methodologically loose as well as rigorous studies, on the grounds that evaluations of methodological strength differ, and even weak studies contain some increments of information. It treats separately each of the different numbers of outcome items collected in different studies, thus allowing some studies disproportionate weight. Bangert-Drowns (1988) employed"study effect" meta-analysis to examine school-based substance abuse education. The advantage of the study-effect approach is that it is more selective, excluding studies with serious method- ological flaws, and it weights each study equally when average effect sizes are calculated. In a reanalysis, Tobler (1989) applied the more restrictive inclusion criteria and weighting used by Bangert-Drowns and then extended the new analysis by focusing on characteristics of the 10 most effective programs. Tobler I Tobler (1986, 1989) included 143 programs in her first widely cited meta-analysis. Four criteria were used to include a program in the meta- analysis: Use of quantitative outcome measures including mediating variables; Presence of control or comparison groups (however, in many cases these were supplied by Tobler post hoc); . Students in grades 6-12 as recipients of intervention; Prevention as a goal of the intervention (i.e., assisting young people in developing attitudes, values, behavior, and skills that may reduce the likelihood of drug use).

OCR for page 76
EVALUATING PREVENTION PROGRAM EFFECTS 79 Each program was coded for 17 different content items, which were then mapped into five program types: Knowledge-only, meaning purely informational programs about drug effects; Affective-only, meaning largely nondrug-specific curricula to enhance self-esteem or general competency skills (see further discussion below); Knowledge-plus -affective ; Peer programs (which means that some program element focuses on peer interaction, either as a teaching method or as a transmitter of drug behavior this does not necessarily mean training in peer resistance skills), and . Alternatives, generally meaning that the subjects were treated out- side a conventional school environment. In all, 63 variables (e.g., outcome measures, client characteristics, meth- odological issues, program implementation, etc.) that could affect program success were coded. Tobler estimated effect sizes for program success based on outcome variables for drug knowledge; drug attitudes and values; behavioral skills (i.e., decision making, assertiveness, refusal, etc.), in terms of learning the skills and, separately, reporting instances of using them; and self-reported drug use. Tobler (1986) found that the average effect size for change in knowl- edge (0.52) was nearly double the effect for desired change in nondrug behaviors (0.27), skills development (0.26), and self-reported drug use (0.24~. The effect size for attitudinal change was the lowest among the outcomes assessed (0.18~. Knowledge-only programs had measurable effects on knowledge but negligible effects on attitudes and self-reported drug use. Affective- only programs were, in Tobler's analysis, ineffective across all outcome measures. Knowledge-plus-affective programs had a very modest average effect size on drug use (0.15~. Peer programs had the most marked effect on self-reported drug use (0.40~. Alternative programs, which were highly intensive and targeted on high-risk adolescents, were midway between. Tobler's analysis suggests that a significant effect on drug knowledge and attitudes can occur without significant parallel changes in drug use. The analysis also suggests that there are no significant differences in drug use outcome effects between urban and suburban populations and between junior and senior high students. Tobler II Tobler's original report was critically reviewed by Bangert-Drowns (1988~. He noted that an unreported number of the evaluations included in Tobler's analysis were not located in the peer-reviewed literature and, for this and

OCR for page 76
80 PREVENTING DRUG ABUSE: WHAT DO WE KNOW? other reasons, there were far too many methodologically weak reports in the pool of studies analyzed. Moreover, he noted that an unspecified number of the studies did not include sufficient information to calculate effect sizes, which had led Tobler to improvise various unspecified imputation proce- dures. Finally, he noted that the overall results gave very disproportionate weight to a small group of studies with large numbers of outcome measures. (Note: this is also problematic from a statistical significance testing stand- point insofar as the samples are not independent.) Tobler (1989) subsequently reanalyzed 91 of the 143 prevention inter- vention programs included in the original meta-analysis. The weakest stud- ies were evidently excluded. This new analysis was based solely on the self-reported drug use outcome and computed only one effect size for each program. The effect sizes for knowledge-only, affective-only, and knowl- edge-plus-affective programs were all insignificant at 0.07 or less. The effect size on drug use outcome for peer programs was 0.42; for alternatives it was 0.20. These results were quite similar to those originally reported. Tobler achieved further specification by focusing on the "top-10" (highest effect sizes) peer programs. Tobler found certain commonalities here, in particular an emphatic focus on group interaction and delivery of the inter- vention by mental health professionals or counselors rather than regular teachers or peer leaders. The most successful programs for those of junior high age stressed the acquisition of skills, particularly refusal skills, al- though there was evidence of efficacy for broad-spectrum (decision making, competency, life) skills as well. The top peer programs among those of high school age featured well-structured group discussions that maintained an emphasis on drugs. Tobler notes that individual sessions often aug- mented the group sessions. Based on these results of scrutinizing the top 10, Tobler reanalyzed the data from the 91 programs and found that overall effect sizes for mental health professionals or counselors were at least twice the effect size for health education specialists, peer leaders, teachers, college students/others, and a combination of mental health professionals or counselors and teach- ers. Tobler (1989:19) noted: "The success of the peer programs is not dependent on the leader but is enhanced by the presenter.... Mental health professionals or counselors were represented almost entirely in the peer strategies. This combination produced the highest average effect size (0.80~. When peer leaders or teachers were used in the peer strategies, their aver- age effect sizes were equivalent (0.31~." As clear as these results appear, direct scrutiny of the top-10 programs yields ambiguities and obstacles to generalization that neither Bangert-Drowns's nor Tobler's reanalysis addresses. One cardinal point is that Tobler's ge- neric use of the term drug includes cigarettes and that 4 of the top-10 peer programs (and an uncertain number of others in the sample) focused exclu

OCR for page 76
EVALUATING PREVENTION PROGRAM EFFECTS 81 sively on cigarettes; only 3 of the 10 included measures of alcohol, mari- juana, or other drugs. Half of the top 10 did not use an experimental design involving random assignment. Just 2 of the 10 studies drew representative samples of students experimentally assigned to treatment and control condi- tions, and in both of those studies the interventions (and outcomes reported) are specifically on cigarette smoking. In addition, program subjects were not generally followed up for long; only two had a follow-up period beyond 1 year. Despite Tobler's selectivity, the general methodological rigor and relevance of the studies included remains low. Although this would not in itself invalidate the results, a closer look at a handful of the top-10 pro- grams stipulated by Tobler, those available in peer-reviewed venues and not restricted to cigarette smoking, provides a revealing perspective on the meta- analytic results. One of these programs was reported by Sorensen and Jaffe (19754. It involved a total of 10 adolescents who were self-recruited to a 14-week, once-a-week "drug group" organized by a paraprofessional staff member in a storefront community youth center. Four recruits stopped participating after one or two sessions (three after a confrontation over coming to group meetings while intoxicated or in an otherwise disruptive condition); these four were used as the control group. The other six participants reported lifetime use of 9 drugs, while early departees averaged 14 drugs. These results yield an effect size of 0.71; they were, however, pastiest data. No pretest data had been collected to ascertain whether control and treatment groups had different drug experiences even before the intervention, which the reasons given for the creation of the "dropout" control group certainly suggest. In a second top-10 program, Wunderlich et al. (1974) reported on a procedure instituted in a juvenile court, in which short-term group therapy was prescribed for adolescents and their parents. The treated group of 100 parent-child cases comprised juvenile drug offenders 14-19 years old (aver age age 16.6), three-fourths of whom had been detained specifically on drug charges; 85 percent of their parents participated in 12-week parent groups (which were separate from those for the adolescents). The 100 comparison cases were juvenile offenders 9-18 years old (average age 15), 62 percent of whom had been detained for nondrug-related felony offenses and 33 percent for the status offense "in need of supervision." All of the comparison group were referred to detention centers, forestry camps, or juvenile services pro- bation. At 2-year follow-up, the comparison group (although nearly two grades younger) had left school more often (25 versus 15), been rearrested more often on nondrug offenses (41 versus 11), and had more drug rearrests (3 versus 2) the last statistic yielding an effect size of 0.62. In Tobler's third top-10 study, Chambers and Morehouse (1983:84-85) reported on a school-based student assistance program in which counse

OCR for page 76
82 PREVENTING DRUG ABUSE: WHAT DO WE KNOW? lore with master's degrees conducted individual, family, and group ses- sions for students. The program was publicized by counselor presenta- tions in classrooms and letters sent home. According to the authors, "Ex- cept for students referred . . . because they were caught using alcohol or drugs, participation is voluntary." About 70 percent of the students in the program were classified as alcohol or drug abusers. How many of these were mandatory referrals is unclear. Details of the evaluation procedure are quite sketchy in the published report, and it is not clear what com- prised a control group. Based presumably on unpublished data, Tobler calculated an effect size of 0.94. The fourth top-10 study was the only one of the four employing a persuasively equivalent control group of reasonable size against which the program effect size was inferred, and it was the only one using a sample of students generalizable to most school settings (although not to the general population of students). In this study, Horan and Williams (1982) reported an experiment in which the least assertive one-third of girls and boys, re- spectively, in an 8th grade cohort were randomly assigned to three condi- tions: active treatment, "placebo" sessions (both types administered by master's-level counselors), or no treatment. The students were tested just prior to the intervention, immediately after the intervention, and again at a 3-year follow-up. The active treatment consisted of five 45-minute sessions of assertion training over a 2-week period, each session involving three new exercises (one of which was a peer-pressure-to-use-drugs type of stimulus) and live modeling, role-playing, and correction of the assertive response. The placebo sessions were comprised of discussions of assertiveness, peer pressure, and drug use-but no modeling or role-playing. There were no pre-post assertiveness effects in the placebo or control groups, and no 3-year differences between placebo and controls in their use of alcohol and marijuana or hard drugs. The active training group, how- ever, gained significantly in pre-post assertiveness, and at 3-year follow-up they reported three times as many total refusals and one-third as many total episodes of using drugs; however, the many zero reports and high variance in quantities marginalized the statistical significance of these results. In summary, of the four top-10 peer programs reported in accessible, refereed publications, only the one (Horan and Williams) engenders scien- tific confidence on the basis of a sound design and here, the result for which effect size was calculated was statistically suspect. Even more trouble- some than the prevailing methodological defects is the fact that these inter- ventions are not, by and large, drug prevention programs as the term is generally understood. Admission to three of the four programs just re- viewed required substantial levels of drug-related problems to begin with; even the fourth program was quite selective, excluding two-thirds of stu- dents. Calling these interventions prevention rather than treatment or reha

OCR for page 76
EVALUATING PREVENTION PROGRAM EFFECTS 83 bilitation is difficult to justify. The fact that counseling professionals pro- duced better results would certainly be expected if the programs were in fact therapeutic rather than prophylactic interventions. Tobler's results in favor of peer programs that is, interventions refer- ring to peer interaction as a teaching or therapeutic method may be con- sidered suggestive to the degree that where there is smoke, even smoke amplified by mirrors, there may be fire. There is certainly a marked con- trast between the positive peer results and the uniformly negative results found with three other types of interventions. Nevertheless, when closely examined, the fruits of Tobler's meta-analysis can be considered imagina- tive and provocative but hardly persuasive concerning the question of how effective prevention programs may be. Other Meta-Analyses Bangert-Drowns studied a selection of educational programs much more tightly screened than Tobler's. He limited the analysis to studies meeting the following stringent criteria: the programs had to be conducted in schools with "traditional students", tobacco-only programs were excluded; a no- treatment control had to be used that was shown not to be significantly different before treatment from the experimental group; and the original data had to be reported in sufficient detail to permit unambiguous calcula- tion of effect sizes. Under these selection criteria, only 33 programs were admitted to the meta-analysis. Most were knowledge-only or knowledge-plus-affective pro- grams, in Tobler's terms, and most used teachers to deliver the intervention. In all, 4 were in elementary schools, 12 in junior high or middle schools, and 17 in high school or college. Slightly over half the interventions fo- cused exclusively on alcohol education, and half were of 5 weeks' duration or less. The evaluations employed three outcome criteria: knowledge about substances (alcohol or drugs); attitudes toward substances, their use, and abuse; and behavior with regard to substances. Of them, 26 evaluations measured knowledge, 18 measured attitudes, and 14 measured behavior; only 3 studies measured all three criteria (Bangert-Drowns, 19881. Effects on knowledge were highest (average effect size 0.76), effects on attitudes were lower (0.34), and effects on behavior were lowest (0.12), not differing significantly from zero. No identified study feature had a consis- tent differential effect on knowledge. However, two program features dif- ferentially affected attitudinal results: the mode of delivery, with lecture- only as the weakest mode, and the use of peer leaders, which had significantly higher average effects in the desired direction compared with adult-led condi- tions, a result differing from Tobler's. Two study features reliably related to behavioral outcomes were the year of publication (the more recent the

OCR for page 76
84 PREVENTING DRUG ABUSE: WHAT DO WE KNOW? techniques, the higher the effects) and whether the students volunteered rather than being forced to participate (volunteers had higher effects). Bangert-Drowns's sample of evaluations were skewed toward higher grades, toward an alcohol focus, and toward programs of very short dura- tion compared with Tobler's selections. Since only a handful of the evalua- tions included knowledge, attitude, and behavior in the same design, con- clusions about the relative effect sizes must be viewed with caution. Bangert-Drowns's exclusion of studies with significant pretreatment differ- ences between experimental and control groups does not clarify what con- stituted significant initial nonequivalence in particular, whether statistical controls over initial conditions were accepted. Another consideration of the comparison of methods using meta-analysis is whether the grouping of studies in each category of intervention method (e.g., cognitive, cognitive-plus-affective) constituted a homogeneous set as measured by the pretest or pastiest effect sizes. If not, those studies with extreme effect sizes (outliers) should be removed from the group comparison. Bruvold and Rundall (1988) published a meta-analysis and theoretical review of 19 school-based tobacco- and alcohol-oriented intervention stud- ies. The 19 studies all utilized a control or comparison group and met 5 design criteria. The analysis contrasted the "rational" prevention theory of Fishbein and Ajzen (1975) with the social reinforcement and learning theory of Bandura (1977), the social norms/problem behavior theory of Jessor and Jessor (1977), and the developmental theory of Rosenberg (19791. Interventions based on the traditional rational teaching model had a significantly greater effect on knowledge than did the other models. How- ever, other interventions had greater positive impact on attitudes and to- bacco and alcohol behavior than the rational model. Bruvold and Rundall suggest that a threshold change in knowledge is necessary for behavior change, but attitude changes (in the desired direction) do not necessarily follow from knowledge changes. A combination of new knowledge and attitude changes is more certain to produce behavioral results. Traditional didactic approaches are less effective than other means social reinforce- ment, normative, or developmental approaches in generating the sequence of attitudinal and behavioral changes. Bruvold and Rundall concluded (1988: 72-73~: "If an individual receives peer praise and support for refusing cigarettes, the individual will become fully convinced that such refusals lead to peer praise and support, a desirable outcome ...." Interventions targeted at self-esteem enhancement, if they appropriately followed the te- nets of this theory, would be directed at providing the individual more constant and explicit feedback from significant other peers. A meta-analysis by Hansen et al. (1990) was based on 85 distinct co- horts of subjects. The results reveal that sample retention decreases over time: the mean proportion of subjects retained in the analyses decreased

OCR for page 76
EVALUATING PREVENTION PROGRAM EFFECTS 85 from 81.3 percent to 67.5 percent from follow-ups taken at 3 months and 3 years, respectively. There was considerable variability in the rates of attri- tion between studies. The greatest drop in sample retention was found to occur during the first year of investigation. The authors concluded that researchers should interpret their results in light of the rate of attrition and should further their efforts to reduce the rate of attrition. The results of Project ALERT, discussed later in this chapter, are particularly subject to this conclusion. Summary Tobler's, Bangert-Drowns's, and Bruvold and Rundall's results con- verge on the general ineffectiveness of knowledge-only, affective-only, and knowledge-plus-affective programs in affecting alcohol or drug use behav- iors. Hansen et al. (1990) provide a warning on long-term effects due to the attrition of subjects over time. Tobler and Bangert-Drowns diverge on what kind of trainers seem best to induce informational or attitudinal change, but these results may simply reflect the different kinds of programs analyzed. Tobler's review suggests that programs oriented toward peer relationships gain in efficacy, but it leaves open the question of what this advantage consists of and whether it actually applies to drug prevention programs among general student populations. The strength of Tobler's meta-analysis is its overview of different program types, but the strongest conclusion is difficult to regard as applicable to prevention programs at all. These results suggest that we need to examine studies of prevention interventions that employ much more tightly defined contents and more careful scientific de- signs than appear typical among the types of studies that carry so much weight in some of the meta-analyses. A good set of cases in point for preferred studies are the Life Skills Training Program, several studies using a cognitive-behavioral approach, and the Napa Drug Abuse Prevention Project. In each case, the research involved programs with discrete modular charac- teristics, applied to full grade cohorts, within closely controlled experimen- tal protocols. THREE PROGRAMS MEETING TOBLER'S CRITERIA Life Skills Training Program Life Skills Training (LST) is a middle-school curriculum with three components (Botvin and Wills, 1985; Botvin and Eng, 1982; Botvin et al., 1983): e Substance-specific information and refusal skills training;

OCR for page 76
86 PREVENTING DRUG ABUSE: WHAT DO WE KNOW? A personal skills component to improve critical thinking and respon- sible decision making, help cope with anxiety, and learn principles of self- improvement; and . Improvement of nonverbal and verbal communication skills for so- cial encounters including dating, conversation, and assertiveness. The Life Skills Training program was implemented with booster ses- sions among a predominantly white sample of 7th grade students who were followed up in grades 8 and 9 (Botvin et al., 19901. Using a randomized block design, schools were assigned to receive one of three programs: (1) the LST program with formal provider training and implementation feed- back, (2) LST with videotaped provider training and no feedback, or (3) no treatment. Program outcomes showed significant reduction in smoking and marijuana use in both experimental conditions at the first and second year follow-up. The program did not have significant effects on drinking fre- quency or amount, although at second year follow-up there was a signifi- cant effect on the frequency of getting drunk for the experimental groups who received videotape teacher training. The effect was strongest for ciga- rette use; this is not surprising, as the intervention was originally designed for smoking prevention. These findings provide the most rigorous test of the LST approach and demonstrate the effectiveness of LST in reducing substance-using behaviors among youth in grades 7 to 9. There is further evidence of short-term efficacy of the LST approach to drug prevention. The program reduced the proportion of smoking among a sample of black urban youths by 56 percent in a 3-month pastiest (Botvin et al., 1989a). A skills training program for smoking prevention was tested in a predominantly Hispanic population, preliminary evidence supported the efficacy of the program (Botvin et al., 1989b). These findings suggest that a preventive approach with some short-term effectiveness in white middle- class populations may be generalizable to minority populations. There is some evidence of long-term efficacy using the LST approach with regard to cigarettes. Smoking prevention integrated into a primary cancer center prevention strategy with diet modification revealed that the rate of initiation of cigarette smoking was significantly lower in treatment schools 6 years following the intervention (Walter et al., 1989~. In grade 4 no smokers were present in the intervention and nonintervention groups; the rate of initiation of cigarette smoking was 73.3 percent less (3.5 versus 13.1 percent) among youths in the intervention schools than those in noninter- vention schools; and the effect was stronger for males than for females. An 8-year follow-up study in Finland (North Karelia Youth Project) revealed that the positive short-term effects on smoking prevalence found immedi- ately following the intervention and in a 4-year follow-up diminished by the 8-year follow-up. The difference in smoking prevalence, however, remained

OCR for page 76
108 PREVENTING DRUG ABUSE: WHAT DO WE KNOW? The mass media can play an important role in creating awareness- knowledge, in stimulating interpersonal communication, and in recruiting individuals to participate in campaign activities. Interpersonal communication through peer networks is very impor- tant in leading to and maintaining behavior changes. . The perceived credibility of a communication source or channel en hances the effectiveness of a communication campaign. . Formative evaluation can improve the effectiveness of campaigns by producing messages that are specific to the desired behavior change. Campaign appeals that are socially distant from the audience mem- ber are not effective. Campaigns promoting prevention are less likely to be successful than those with immediate positive consequences. Audience segmentation strategies can improve campaign effective- ness by targeting specific messages to particular audiences. Audience seg- mentation strategies have focused almost entirely on sociodemographic char- acteristics or on specific drugs such as cocaine. The next step will be to use the existing literature on risk and protective factors to identify individuals at higher risk for drug use or abuse and target messages specifically at these groups. In fact, this is the basis for the Donohew et al. (1990a' emphasis on high sensation seeking, an identified risk factor for drug use. Timeliness and accessibility of media and interpersonal messages . . . can contribute to campaign success. These characteristics of effective messages provide an important begin- ning point for future research on media effects on drug use and abuse and in antidrug prevention campaigns. However, the guiding principle of the en- tire enterprise has been identified by Roberts and Maccoby (1985:544~: ". . . the ubiquity and assumed homogeneity of media content can make one forget that meanings are not in messages, but in people." There are at least three lessons that have been learned from prior re- search. First, media alone are much less effective than media messages employed in the context of a broad campaign that includes the use of inter- personal channels. Second, there is a need for targeting or audience seg- mentation. Third, there is a strong need for formative research in message and campaign design. The media are only one tool in the hands of those concerned with drug abuse prevention, albeit a very important one. CONCLUSIONS AND RESEARCH NEEDS The only way to determine if something really works is to try it, in a way that permits objective evaluation. Systematic testing and evaluation are essential to progress in reducing drug abuse. A clear majority of the

OCR for page 76
EVALUATING PREVENTION PROGRAM EFFECTS 109 research published as evaluations of the effectiveness of preventive inter- ventions is methodologically weak. Corrections of their weaknesses is not a matter of applying rigid formulae. It requires patient commitment to attracting quality researchers to the field; applying stringent requirements to publications and research grants, and urging other research sponsors, col- laborators (such as school administrators), reviewers, and publication edi- tors to attend to them; developing and supporting appropriate research train- ing; and attending to socioenvironmental aspects and data quality control elements of proposed research. Social Influence Research Much of the work on social influence approaches to interventions com- pleted to date has focused on preventing or delaying onset of use of the gateway drugs. But preventing or delaying onset is only part of the drug using and abusing continuum. The entire continuum of transitions in drug use (e.g., initiation, continuation, progression, regression, cessation, relapse) constitute the proper focus of attention for prevention interventions (Clayton, 1992). A number of major methodological issues need to be addressed directly and critically. The first of these is attrition. While attrition rates are often reported, the analyses usually show demographic and pretest differences on gross drug use measures between those who remained in the studies and those who dropped out of the study by treatment condition. Very few researchers examine or report such differences on the major predictive or mediating variables. The attrition rates in longitudinal studies on preven- tion fall below rates achieved by large-scale national studies such as High School and Beyond, Monitoring the Future, and the National Education Longitudinal Study. It is essential that panel studies meet attrition stan- dards that amount to the state of the art in survey research. A second major methodological issue is statistical power. Most evalua- tions of prevention interventions suffer from a lack of statistical power to detect differences. When significant main effects fail to emerge, it is com- mon to make too much of subgroup differences. A third major method- ological issue concerns contamination. In the United States, it is virtually impossible to find a true no-treatment control group. However, none of the studies describes the prevention intervention received by the so-called con- trol group members. Clayton and Cattarello (1990) have identified a series of implementa- tion issues concerning social influence curricula that should receive atten- tion. Standards for reporting implementation information scarcely exist, and too often it is virtually impossible to say what actually occurred in an intervention (Moskowitz, 1989~. A set of standards such as those discussed

OCR for page 76
0 PREVENTING DRUG ABUSE: WHAT DO WE KNOW? by Clayton and Catalano should be promulgated as an evaluation criterion for NIDA-sponsored intervention research. It is clear that different curricula are being used by different research- ers, but explicit comparisons are just beginning to be made (see Rogers et al., 1989~. Comparing the efficacy of different social influence programs, for example, may be comparing the proverbial apples and oranges until standard descriptive frameworks and measures of what actually occurs in the classroom are developed, tested, and widely used. There may be differ- ent pedagogical strategies employed even by teachers or trainers working from the same book in adjacent classrooms delivering, presumably, the same lessons. These differences may be systematically related to the different roles occupied by those delivering the curriculum; to date the evidence on role effects (peer leaders, health educators, classroom teachers, counselors or mental health professionals, substance abuse specialists, police officers) is a raft of inconsistencies. A methodological initiative is needed to de- velop a gauge of trainers' ability to communicate content accurately, intelli- gibly, and in ways consistent with the theory intended to be applied by the intervention. The skills being taught in these interventions require different levels of ability for abstraction and specificity. There is little research on how a single curriculum teaching such skills affects youth in a grade cohort who have attained different developmental levels. There are few instances in which research projects have measured actual individual student exposure to the prevention intervention, to see whether exposure level is connected to measured outcomes; if there is an individual dose-response effect, this would substantially raise our confidence that outcomes and program features were indeed causally linked. It is also important to find some way to assess the degree to which curriculum is embedded in the school milieu. Finally, we add our concern to that of Kozlowski et al. (1989:455) and Flay (1985) about advocacy for social influence interventions in the ab- sence of even moderately compelling evidence of efficacy. Ethnicity and Gender: The Neglected Dimensions Most school-or~ented drug prevention programs are based on mainstream, one-size-fits-all cultural assumptions. Data on differential effects by ethnicity of recipient students have been notably scarce in evaluations of major school- based prevention programs; either no disaggregation by ethnicity is pro- vided by the evaluators, or the sample sizes for which data are available are too small for any differential zero-order or partially controlled effects to be statistically discernible. Differentiation of effects by gender is more com- mon, and there are glimmers of evidence that prevention programs are more effective with girls. One might assume that girls are a population that is

OCR for page 76
EVALUATING PREVENTION PROGRAM EFFECTS 111 more compliant to begin with, but assumptions will not take the place of . . . c .eeper investigation. An important exception to the rule of not reporting ethnic results is Graham and colleagues (1990), who evaluated short-term program effects of a social influence program (SMART) among Los Angeles 7th graders. There was a significant program effect for Asian students, nonsignificant positive effects for Hispanic and black students, and null effects for white students. There were group differences with respect to different drugs. Moreover, virtually all positive program effects were among girls, suggest- ing that gender role norms interact strongly with ethnic group differences. Koepke et al. (1990) found that in a cigarette smoking prevention and cessation program addressed to middle school students and their parents in San Diego and Los Angeles counties (where one-fifth of all Hispanics in the United States reside), black parents and children were more likely than white, Hispanic, or Asian ones to assess the parents as potentially effective in preventing their children from smoking, but Hispanic parents were more likely to implement "say no" teaching. School-based drug prevention programs that are not based on one-size- fits-all models but rather on culturally specific tailoring do exist, and these have been described to some extent in the literature. Most are adjunctive to a community-based program; however, none has been satisfactorily evalu- ated to date using well-designed outcome measures to test their effective- ness (Orlandi, 1986~. There have been some evaluations among commu- nity-based prevention programs; for example, Schinke and colleagues (1988) pilot-tested a program of culturally specific training in competence skills using random-assignment designs among bicultural Native Americans liv- ing on reservations; they reported desired effects on drug use prevalence. We will return to issues of cultural and community specificity in the appen- dix, where we provide a more elaborate discussion of how research can be structured to yield more usefully articulated results taking these specifici- ties into account. Generic Interventions Substance abuse is nested within a range of other high-risk activities, and it is highly plausible that progress in reducing the most serious levels of illicit drug use will require broad rather than narrow interventions. There is evidence throughout the prevention literature that training in resistance skills and information on health risks may be relatively puny if not counterpro- ductive forces in the lives of many high-risk children, compared with other problems that may overwhelm them. In studies relevant to substance abuse, intensive interdisciplinary programs that deal with more central aspects of their behavior show promise to meaningfully improve the prospects of these

OCR for page 76
112 PREVENTING DRUG ABUSE: WHAT DO WE KNOW? young people, although the specific effects on drug problems are as yet unknown. REFERENCES Bandura, A. 1977 Social Learning Theory. Englewood Cliffs, N.J.: Prentice Hall. Bangert-Drowns, R.L. 1988 Effects of school-based substance abuse education: a mete analysis. Journal of Drug Education 18(3):243-264. Battistich, V., D. Solomon, M. Watson, J. Solomon, and E. Schaps 1989 Effects of an elementary school program to enhance prosocial behavior on children's cognitive social problem-solving skills and strategies. Journal of Applied Devel- opmental Psychology 10: 147-169. Bell, C.S., and R. Battjes 1987 Prevention Research: Deterring Drug Abuse Among Children and Adolescents. NIDA Research Monograph 63. Rockville, Md.: National Institute on Drug Abuse. Best, J.A., B.R. Flay, S.M.J. Towson, K.B. Ryan, C.L. Perry, K.S. Brown, M.W. Kersell and J.R. d'Avernas 1984 Smoking prevention and the concept of risk. Journal of Applied Social Psychol- ogy 14(3):257-273. Best, J.A., S.J. Thomson, S.M. S anti, E.A. Smith, and E.S. Brown 1988 Preventing cigarette smoking among school children. Annual Review of Public Health 9: 161 -201. Black, G.S. 1989 The Attitudinal Basis of Drug Abuse. The Third Year. Report prepared for the Partnership for a Drug Free America. Gordon S. Black Corporation, Rochester, New York. Botvin, G.J., and A. Eng 1982 The efficacy of a multicomponent approach to the prevention of cigarette smok- ing. Preventive Medicine 11:199-211. Botvin, G.J., and T.A. Wills 1985 Personal and social skills training: cognitive-behavioral approaches to substance abuse prevention. Pp. 8-49 in C.S. Ball and R. Battjes, eds., Prevention Research: Deterring Drug Abuse Among Children and Adolescents. NIDA Research Mono- graph 63. Rockville, Md.: National Institute on Drug Abuse. Botvin, G.J., N.L. Resnick, and E. Baker 1983 The effects of scheduling format and booster sessions on a broad spectrum psychosocial approach to smoking prevention. Journal of Behavioral Medic~ne 6(4):359-379. Botvin, G.J., H.W. Batson, S. Witts-Vitale, V. Bess, E. Baker, and L. Dusenbury 1989a A psychosocial approach to smoking prevention for urban black youth. Public Health Reports 12(3):279-296. Botvin, G.J., L. Dusenbury, S. James-Oritz, and J. Kerner 1989b A skills training approach to smoking prevention among Hispanic youth. Journal of Behavioral Medicine 12(3) :279-296. Botvin, G.J., E. Baker, L. Dusenbury, S. Tortu, and E.M. Botvin 1990 Preventing adolescent drug abuse through a multi-modal cognitive-behavioral ap- proach: results of a 3-year study. Jo7~rnal of Consult~ng and Clinical Psychology 58(4):437-446. Bruvold, W.H., and T.G. Rundall 1988 A mete analysis and theoretical review of school based tobacco and alcohol inter- vention programs. Psychology and [Iealth 2:53-78.

OCR for page 76
EVALUATING PREVENTION PROGRAM EFFECTS 113 Chaffee, S.H. 1977 Mass media effects: new research perspectives. Pp. 210-241 in D. Terror and L. Nelson, eds., Communication Research-A Half Century Appraisal. Honolulu: East-West Center Press. Chambers, J., and E. Morehouse 1983 A cooperative model for preventing drug and alcohol abuse. National Association of Secondary School Principals Bulletin 81-87. Chassin, L. 1984 Chapter in P. Karoly and J. Steffen, eds., Adolescent Behavior Disorders. Lexing ton, Mass.: Lexington Books. Clayton, R.R. 1992 Transitions in drug use: risk and protective factors. Pp. 15-51 in M. Glanz and R. Pickins, eds., Vulnerability to Drug Abuse. Washington, D.C.: American Psycho- logical Association. Clayton, R.R., and A. Cattarello 1990 Prevention intervention research: the challenges and opportunities. In C. Leukefeld and W. Bukoski, eds., Drug Abuse Prevention Intervention Research: Method- ological Issues. Rockville, Md.: National Institute on Drug Abuse. Clayton, R.R., A. Cattarello, L.E. Day, and K.P. Walden 1991 Persuasive communications and drug prevention: an evaluation of the D.A.R.E. program. In H. Sypher, L. Donohew, and W. Bukoski, eds., Persuasive Communi- cation and Drug Abuse Prevention. Boston: Erlbaum. DeJong, W. 1987 A short-term evaluation of project DARE (Drug Abuse Resistance Education): preliminaryindicationsofeffectiveness. JournalofDrugEducation 17(4):279- 294. Donohew, L., E. Lorch, and P. Palmgreen 1990a Sensation seeking and targeting of televised anti-drug PSAs. In L. Donohew et al., eds., Persuasive Communication and Drug Abuse Prevention. Hillsdale, N.J.: Lawrence Erlbaum and Associates. Donohew, L., P. Palmgreen, E. Lorch, and W.F. Skinner 1990b Personal communication. Dwyer, J.H., D.P. MacKinnon, M.A. Pentz, B.R. Flay, W.B. Hansen, E.Y.I. Wang, and C.A. Johnson 1989 Estimating intervention effects on longitudinally observed health behaviors: the Midwestern Prevention Project. American Journal of Epidemiology 130:781-795. Ellickson, P.L., and R.M. Bell 1990 Drug prevention in junior high: a multi-site longitudinal test. Science 247:1299- 1305. Faine, J.R. Ellickson, P.L., R.M. Bell, M.A. Thomas, A.E. Robyn, and G.L. Zellman 1988 Designing and Implementing Project ALERT: A Smoking and Drug Prevention Expe'-ience. Santa Monica, Calif.: Rand Corporation. 1989 D.A.R.E. in Nashville Schools. Western Kentucky University Social Research Laboratory, Bowling Green, Kentucky. Faine, J.R., and E. Bohlander 1988 Drug Abuse Resistance Education: An Assessment of the 1987-88 Kentucky State Police DARE Program. Western Kentucky University Social Research Labora- tory, Bowling Green, Kentucky. Fishbein, M., and I. Ajzen 1975 Belief, Attitude, Intention, and Behavior: An Introduction to Theory and Re- search. Reading, Mass.: Addison-Wesley.

OCR for page 76
114 PREVENTING DRUG ABUSE: WHAT DO WE KNOW? Flay, B.R. 1985 What we know about the social influences approach to smoking prevention: re view and recommendations. Pp. 67-112 in C.S. Bell and R. Battjes, eds., Preven tion Research: Deterring Drug Abuse Among Children and Adolescents. NIDA Research Monograph No. 63. Rockville, Md.: National Institute on Drug Abuse. Flay, B.R. 1987 Mass media and smoking cessation: a critical review. American Journal of Public Health 77(February):153-160. Flay, B.R., and J.L. Sobel 1983 The role of mass media in preventing adolescent substance abuse. Pp. 5-35 in T.J. Glynn et al., eds., Preventing Adolescent Drug Abuse: Intervention Strategies. NIDA Research Monograph 47. Rockville, Md.: National Institute on Drug Abuse. Flay, B.R., C.A. Johnson, W.B. Hansen, L.M. Grossman, J.L. Sobel, and L.M. Collins 1983 Evaluation of a School-Based, Family-Oriented, Television-Enhanced Smoking Prevention and Cessation Program: The Importance of Implementation Evalua- tion. Paper presented at the joint meeting of Evaluation Network and the Evalua- tion Research Society, Chicago. Flay, B.R., K. Koepe, S.J. Thomson, S. Santi, A. Best, and S.K. Brown 1989 Six year followup of the first Waterloo school smoking prevention trial. American Journal of Public Health 79(10):1371-1376. Forman, A., and S.B. Lachter 1989 The National Institute on Drug Abuse cocaine prevention campaign. Pp. 13-20 in P.J. Shoemaker, ea., Communication Campaigns About Drugs: Government, Me- dia, and the Public. Hillsdale, N.J.: Lawrence Erlbaum Associates. Gilchrist, L.D., S.P. Schinke, J.K. Bobo, and W.H. Snow 1986 Self-control skills for preventing smoking. Addictive Behaviors l l :169-174. Gilchrist, L.D., S.P. Schinke, J.E. Trimble, and G.T. Cvetkovich 1987 Skills enhancement to prevent substance abuse among American Indian adoles- cents. International Journal of the Addictions 22:869-879. Glass, G., B. McGaw, and M. Smith 1981 Meta-Analysis in Social Research. Beverly Hills, Calif.: Sage Publications. Goplerud, E., ed. 1991 A Practical Guide to Substance Abuse Prevention in Adolescence. OSAP Preven- tion Monograph 8. DHHS Pub. No. (ADM)91-1725. Washington, D.C.: U.S. Government Printing Office. Graham, J.W., C.A. Johnson, W.B. Hansen, B.R. Flay, and M. Gee 1990 Drug use prevention programs, gender and ethnicity: evaluation of three seventh- grade Project SMART cohorts. Preventive Medicine 19(3):305-313. Green, J.J., and J.M. Kelly 1989 Evaluating the effectiveness of a school drug and alcohol prevention curriculum: a new look at "Here's Looking at You Two." Journal of Drug Education 19(2):117- 132. Hansen, W.B., C.A. Johnson, B.R. Flay, D. Phil, J.W. Graham, and J. Sobel 1988 Affective and social influences approaches to the prevention of multiple substance abuse among seventh graders: results from Project SMART. Preventive Med~cine 17(2): 135-154. Hansen, W.B., N.S. Tobler, and J.W. Graham 1990 Attrition in substance abuse prevention research. Evaluation Review 14(6):677 685. Hawkins, J.D., and R.F. Catalano 1987 The Seattle Social Development Project: Progress Report on a Longitudinal Pre

OCR for page 76
EVALUATING PREVENTION PROGRAM EFFECTS 115 vention Study. Paper presented at the National Institute on Drug Abuse Science Press Seminar, Washington, D.C. Hawkins, J.D., D.M. Lishner, and R.F. Catalano, Jr. 1986 Childhood predictors and the prevention of adolescent substance abuse. Pp. 75- 125 in C.L. Jones and R.J. Battjes, eds., Etiology of Drug Abuse: Implications for Prevention. NIDA Research Monograph No. 56. Rockville, Md.: National Insti- tute on Drug Abuse. Hochheimer, J.L. 1981 Reducing alcohol abuse: a critical review of education strategies. Pp. 286-335 in M.H. Moore and D.R. Gerstein, eds., Alcohol and Public Policy: Beyond the Shadow of Prohibition. Washington, D.C.: National Academy Press. Hopkins, R.H., A.L. Mauss, K.A. Kearney, and R.A. Weisheit 1988 Comprehensive evaluation of a model alcohol education curriculum. Journal of Studies on Alcohol 49(1):38-50. Horan, J.J., and J.M. Williams 1982 Longitudinal study of assertion training as a drug abuse prevention strategy. American Educational Research Journal 19(3) :341-35 1. Huba, G.J., J.A. Wingard, and P.M. gentler 1981 A comparison of two latent causal variable models for adolescent drug use. Jour- nal of Personality and Social Psychology 40:180-193. Jessor, R., and S.L. Jessor 1977 Problem Behavior and Psychosocial Development: A Longitudinal Study of Youth. New York: Academic Press. Johnson, C.A., M.A. Pentz, M.D. Weber, J.H. Dwyer, N. Baer, D.P. MacKinnon, W.B. Hansen, and B.R. Flay 1990 Relative effectiveness of comprehensive community programming for drug abuse prevention with high-risk and low-risk adolescents. Journal of Consulting and Clinical Psychology 58(4):447-457. Koepke, B.L., B.R. Flay, and C.A. Johnson 1990 Health behavior and minority families: the case of cigarette smoking. Family Community Health 13(1):35-43. Kozlowski, L.T., R.B. Coambs, R.G. Ferrence, and E.M. Adlaf 1989 Preventing smoking and other drug use: let the buyer beware and the interven- tions be apt. Canadian Journal of Public Health 80:452-456. Kumpfer, K.L. 1987 Special populations: etiology and prevention of vulnerability to chemical depen- dency in children of substance abusers. Pp. 1-73 in B. Brown and A. Mills, eds., Youth at High Risk of Substance Abuse. DHHS Pub. No. (ADM)87-1537. Rockville, Md.: National Institute on Drug Abuse. Maslow, A. 1980 Motivation and Personality. New York: Harper and Row. Mauss, A.L., R.H. Hopkins, R.A. Weisheit, and K.A. Kearney 1981 A Longitudinal Evaluation of the "Here's Looking at You" Alcohol Education Program. Final Report. Social Research Co., Pullman, Washington. McGuire, W.J. 1968 Personality and susceptibility to social influence. Pp. 1130-1187 in E.F. Borgatta and W.W. Lambert, eds., Handbook of Personality Theory and Research. Chi- cago: Rand McNally. Moskowitz, J.M. 1989 Guidelines for reporting outcome evaluation studies of HPDP programs. In M.T. Braverman, ea., Evaluating Health Promotion Programs. San Francisco: Jossey Bass.

OCR for page 76
16 PREVENTING DRUG ABUSE: WHAT DO WE KNOW? Murray, D.M., P. Pirie, R.V. Luepker, and U. Pallonen 1989 Five- and six-year follow-up results from four seventh-grade smoking prevention strategies. Journal of Behavioral Medicine 12:207-218. Newcomb, M.D., and P.M. gentler 1988 Consequences of Adolescent Drug Use. Beverly Hills, Calif.: Sage Publications. Orlandi, M.A. 1986 Community-based substance abuse prevention: a multicultural perspective. Jour- nal of School Health 56()9):394-401. Pentz, M.A., D.P. MacKinnon, B.R. Flay, W.B. Hansen, C.A. Johnson, and J.H. Dwyer 1989a Primary prevention of chronic diseases in adolescence: effects of the Midwestern Prevention Project on tobacco use. American Journal of Epidemiology 130:713- 724. Pentz, M.A., J.H. Dwyer, D.P. MacKinnon, B.R. Flay, W.B. Hansen, E.Y.I. Wang, and C.A. Johnson 1989b A multicommunity trial for primary prevention of adolescent drug abuse. Journal of the American Medical Association 261:3259-3266. Ray, M. 1973 Marketing communication and the hierarchy of effects. Pp. 147-176 in P. Clarke, ea., New Models for Communication Research. Beverly Hills, Calif.: Sage Publi cations. Ringwalt, C., S. Ennett, and K. Holt 1990 An outcome evaluation of Project D.A.R.E. Personal correspondence, March. 1. Roberts, D., and N. Maccoby 1985 Effects of mass communication. Pp. 539-598 in G. Lindzey and E. Aronson, eds., Handbook of Social Psychology, Vol. 2: Special Fields and Applications. New York: Random House. Rogers, E. 1983 Diffusion of Innovations, 3rd ed. Rogers, E.M., and J.D. Storey New York: Free Press. 1987 Communication campaigns. Pp. 817-846 in C.R. Berger and S.H. Chaffee, eds., Handbook of Communication Science. Beverly Hills, Calif.: Sage Publications. Rogers, T., B. Howard-Pitney, and B.L. Bruce 1989 What Works? A Guide to School-Based Alcohol and Drug Abuse Prevention Curricula. Health Promotion Research Center. Palo Alto, Calif.: Stanford Center for Research in Disease Prevention. Rosenberg, M. 1979 Conceiving the Self. New York: Basic Books. Schaps, E., J. Moskowitz, J. Malvin, and G. Schaffer 1984 The Nap a Drug Abuse Prevention Project: Research Findings. DHHS Publica- tion No. ADM(84)1339. Rockville, Md.: National Institute on Drug Abuse. Schinke, S.P., L.D. Gilchrist, R.F. Schilling, W.H. Snow, and J.K. Bobo 1986 Skills methods to prevent smoking. Health Education Quarterly 13(1):23-28. Schinke, S.P., G.J. Botvin, J.E. Trimble, M.A. Orlandi, L.D. Gilchrist, and V.S. Locklear 1988 Preventing substance use among American-Indian adolescents: a bicultural com- petence skills approach. Journal of Counseling Psychology 35~87-90. Schinke, S.P., A.N. Gordon, and.R.E. Weston 1990 Self-instruction to prevent HIV infection among African-American and Hispanic- American adolescents. Journal of Consulting and Clinical Psychology 58(4):432- 436. Shoemaker, P.J., W. Wanta, and D. Leggett 1989 Drug coverage and public opinion, 1972-1986. Pp. 67-80 in P.J. Shoemaker, ea.,

OCR for page 76
EVALUATING PREVENTION PROGRAM EFFECTS 117 Communication Campaigns About Drugs: Government, Media, and the Public. Hillsdale, N.J.: Lawrence Erlbaum Associates. Solomon, D., M.S. Watson, K.E. Delucchi, E. Schaps, and V. Battistich 1988 Enhancing children's prosocial behavior in the classroom. American Educational Research Journal 25:527-554. Sorensen, J., and S. Jaffe 1975 An outreach program in drug education: teaching a rational approach to drug use. Journal of Drug Education 5(2):87-96. Swisher, J.D., C. Nesselroade, and C. Tatanish 1985 Here's Looking at You Two is looking good: an experimental analysis. Humanis- tic Education and Development (Mar):111-119. Tobler, N.S. 1986 Meta analysis of 143 adolescent drug prevention programs: quantitative outcome results of program participants compared to a control or comparison group. Jour- nal of Drug Issues 16(4):537-567. Tobler, N.S. 1989 Drug Prevention Programs Can Work: Research Findings. Unpublished manu- script, School of Social Welfare, State University of New York, Albany. U.S. Department of Health, Education and Welfare 1964 Report of the Advisory Committee to the Surgeon General on Smoking and Health. Public Health Service. Washington, D.C.: U.S. Department of Health, Education and Welfare. Vartiainen, E., U. Fallonen, A.L. McAlister, and P. Puska 1990 Eight-year follow-up results of an adolescent smoking prevention program: the North Karelia Project. American Journal of Public Health 80(1):78-79. Wachter, K.W., and M.L. Straf, eds. 1990 The Future of Meta-Analysis. New York: Russell Sage Foundation. Walter, H.J., R.D. Vaughan, and E.L. Wynder 1989 Primary prevention of cancer among children: changes in cigarette smoking and diet after six years of intervention. Journal of the National Cancer Institute 81(13):995-999. Warner K. 1989 Effects of an anti-smoking campaign: an update. American Journal of Public Health 79(February):144-151. Wunderlich, R., J. Lozes, and J. Lewis 1974 Recidivism rates of group therapy participants and other adolescents processed by a juvenile court. Psychotherapy: Theory, Research and Practice 2(3):243-245.

OCR for page 76