Addictive Behaviors, Vol. 15, pp. 4743. Printed in the USA. All rights reserved.

1990

A COGNITIVE-BEHAVIORAL PREVENTION: GILBERT

Copyright

0306-4603/90 $3.00 + .OO 0 1990 Pergamon Press plc

APPROACH TO SUBSTANCE ONE-YEAR FOLLOW-UP

J. BOTVIN, ELI BAKER, ANNE D. FILAZZOLA, ELIZABETH M. BOTVIN Cornell University Medical College

ABUSE

and

Abstract - This study presents one-year follow-up data from an evaluation study testing the effectiveness of a cognitive-behavioral substance abuse prevention approach which emphasizes the teaching of social resistance skills within the larger context of an intervention designed to enhance general social and personal competence. The follow-up study involved 998 eighth graders from 10 suburban New York junior high schools. Two schools were assigned to each of the following conditions (a) peer-led intervention, (b) peer-led intervention with booster sessions, (c) teacher-led intervention, (d) teacher-led intervention with booster sessions, and (e) control. The original intervention was implemented in the seventh grade; the booster intervention was implemented during the eighth grade. Results indicate that this type of prevention strategy, when implemented by peer leaders in the seventh grade and when additional booster sessions are provided during the eighth grade, can reduce tobacco, alcohol, and marijuana use. Similar effects are evident for females when the prevention program is implemented with fidelity by classroom teachers. Moreover, the prevention program is also capable of producing a significant impact on several hypothesized mediating variables.

The existing empirical evidence concerning the effectiveness of traditional cognitive and affective education approaches to tobacco, alcohol, and drug abuse prevention have consistently indicated that these approaches are nof effective (Berberian, Lovejoy, & Paparella, 1976; Braucht, Follingstad, Barkarsh, & Berry, 1973; Dorn & Thompson, 1976; Goodstadt, 1974; Richards, 1969; Schaps, Bartolo, Moskowitz, Palley, & Churgin, 1981; Swisher & Hoffman, 1975). There is even some evidence that approaches which attempt to dissuade adolescents from becoming involved with drugs by providing them with factual information concerning the consequences of drug use may actually lead to increased usage, possibly because they may serve to stimulate curiosity (Swisher, Crawford, Goldstein, & Yura, 1971). Toward the end of the 197Os, research conducted by Evans and his colleagues (Evans, 1976; Evans et al., 1978) triggered a major departure from traditional approaches to tobacco, alcohol and drug abuse prevention. Unlike traditional approaches which focus on information dissemination, fear arousal, or moral suasion, the strategy developed initially by Evans and his colleagues was designed to target the social influences believed to promote the initiation of cigarette smoking. The focus of this approach was on increasing students’ awareness of the kind of social pressures to smoke that they would be likely to encounter in an effort to “inoculate’ ’ them against these pressures. It also included demonstrations of specific techniques which could be used to effectively resist these influences, and the periodic monitoring and reporting of actual smoking rates among participating students in an effort to correct normative expectations concerning the prevalence of smoking. Several variations on this prevention model have also been tested. A distinctive feature of these approaches is that they have placed more emphasis on teaching students specific skills This research was supported by a grant to the senior author from the National Institute on Drug Abuse (DA 02835). Requests for reprints should be sent to Gilbert J. Botvin, New York Hospital, Cornell Medical Center, 1300 York Ave., New York, NY 10021. 47

48

GILBERT J. BOTVIN

et al

for effectively resisting both peer and media pressures to smoke, drink, or use drugs. Another distinctive feature of these programs is the use of peer leaders as program providers. Considerable research has been conducted and published documenting the effectiveness of these prevention strategies (e.g., Arkin, Roemhild, Johnson, Luepker, & Murray, 1981; Hurd, et al., 1980; Luepker, Johnson, Murray, & Pechacek, 1983; McAlister, Perry, & Maccoby, 1979; Murray, Johnson, Luepker, Pechacek, & Jacobs, 1980; Perry, Killen, Slinkard, & McAlister, 1980; Telch, Killen, McAlister, Perry, & Maccoby, 1982). Follow-up studies indicate that the positive behavioral effects of these prevention approaches are evident for up to two years after the conclusion of these programs for cigarette smoking (e.g., Luepker et al., 1983; McAlister, Perry, Killen, Slinkard, & Maccoby, 1980; Telch et al., 1982). However, these effects do seem to decay over time, suggesting the need for continued intervention throughout junior and senior high school. Research has also been conducted to test the efficacy of generic cognitive-behavioral skills training approaches to substance abuse prevention (Botvin, Baker, Botvin, Filazzola, & Millman, 1984; Botvin, Baker, Renick, Filazzola, & Botvin, 1984; Botvin & Eng, 1980; Botvin, Eng, & Williams, 1984; Botvin, Renick, & Baker, 1983; Pentz, 1983; Schinke, 1984; Schinke & Blythe, 1981, Schinke & Gilchrist, 1983). In addition to including many of the components of the social resistance skills training approaches, these programs emphasize the acquisition of generic personal and social skills. The findings of studies assessing the efficacy of generic cognitive-behavioral substance abuse prevention approaches indicate that they also significantly reduce cigarette smoking, and that these intervention effects can be produced regardless of whether the primary providers are project staff, social workers, graduate interns, peer leaders, or classroom teachers. Moreover, these approaches have been found to be effective with rural, suburban, and urban students. Evidence also exists indicating that booster sessions may help maintain and even enhance intervention effects. Although both the social influence approaches and the broader cognitive-behavioral approaches have demonstrated rather consistent intervention effects for cigarette smoking, there is only limited evidence that these approaches generalize to other forms of substance use (e.g., Botvin, Baker, Botvin et al., 1984; Botvin, Baker, Renick et al., 1984; McAlister et al., 1980; Pentz, 1983). Moreover, since the studies testing the application of these prevention strategies to substances such as alcohol and marijuana have only recently been conducted, data concerning longer term effectiveness are not yet available. The present paper reports one-year follow-up data from a study designed to test the efficacy of a cognitive-behavioral skills training approach to substance abuse prevention among adolescents (Botvin, Baker, Renick et al., 1984). This study was designed to extend our previous research with cigarette smoking by determining the potential generalizability of this prevention approach to other forms of substance use/abuse. A second objective of this study was to test the relative efficacy of peer leaders and classroom teachers as program providers. Finally, this study was designed to determine the effectiveness of this intervention approach both with and without booster sessions. METHODS

Subjects

Eighth grade students from 10 suburban New York junior high schools were included in the present study. The students in these schools were predominantly white and were from middle class families. Pretest data were collected from 1311 students; pretest and posttest data were collected from 1185 students. Of the original sample of 13 11 7th graders, 1185 (90%) were available for the initial

Substanceabuse prevention

49

posttest and 998 (76%) were available for the one-year follow-up. The students involved in the one-year follow-up were approximately half male (49%) and half female (5 1%). In terms of race/ethnicity, the sample was 13% black, 80% white, 2% hispanic, 2% oriental, and 4% other. The mothers of the students in this sample were well-educated with 65% having attended college or graduate school. Similarly, 70% of the fathers had attended college or graduate school. Most (83%) of the students in this sample came from intact families in which they lived with both their mother and father. Research design The 10 schools participating

in the study had previously been randomly assigned to the following conditions during the first year of the study: (a) prevention program implemented by older peer leaders, (b) prevention program implemented by regular classroom teachers, (c) prevention program with booster sessions implemented by older peer leaders, (d) prevention program with booster sessions implemented by regular classroom teachers, and (e) pretest/multiple posttest control. Two schools were assigned to each experimental condition and two schools were assigned to the control condition. Procedure

Students in the four treatment conditions had previously participated in the 20-session substance abuse prevention program during the seventh grade. Students in conditions 3 and 4 participated in a lo-session booster program during the eighth grade. The booster program was conducted by older (10th) 11th, and 12th grade) peer leaders for the students in condition 3; the booster program was implemented by regular classroom teachers in condition 4. No intervention activities were conducted for students in conditions 1, 2, and 5. All students were assessed by questionnaire at the end of the eighth grade (one year after the initial posttest) for self-reported smoking, alcohol, and marijuana use. The questionnaire also contained items assessing several cognitive, attitudinal, and personality variables presumed to be related to the initiation of substance use/abuse and hypothesized to mediate the effects of the prevention program. Saliva samples were also collected using a variant of the “bogus pipeline” procedure in order to increase the validity of behavioral self-report data (Evans, Hansen, & Mittlemark, 1977). Prevention program

The intervention strategy tested in this study is a multi-component substance abuse prevention curriculum designed to focus on the major social, psychological, cognitive, and attitudinal factors which appear to promote the use of tobacco, alcohol, and marijuana. The main thrust of the prevention curriculum is to facilitate the development of basic life skills and the improvement of personal competence, with particular emphasis being placed on coping with social influences to engage in substance use. The prevention curriculum has been described in detail elsewhere (e.g., Botvin & Dusenbury, 1987; Botvin & Tortu, 1988). The curriculum includes material concerning the consequences of substance use and its social acceptability, decision-making, resisting social influences to engage in substance use, self-directed behavior change, cognitive-behavioral techniques for coping with anxiety, communication skills, general interpersonal skills, and assertiveness. The booster curriculum was designed to reinforce the material contained in the 20-session substance abuse prevention program previously implemented with these students during the seventh grade. As was the case for the seventh grade curriculum, the main thrust of the eighth grade booster curriculum was to facilitate the development of general personal and social competence as well as skills for coping with direct social pressure to smoke, drink, or use

50

GILBERT J. BOTVIN et al.

Table 1. Eighth grade booster sessions Description

Session Cigarette effects

smoking:

Review of the social reasons teenagers smoke; demonstration of the immediate physiological effects of smoking using biofeedback apparatus (pulse meter, tremor testor)

Causes and

Decision making and independent thinking

Review of decision-making skills; behavioral rehearsal with teacher feedback; review of group pressure and persuasive tactics as they relate to decision-making

Advertising

Review and practice of skills

for resisting advertising appeals including the recognition of common ad appeals and formulation of counter-arguments Coping with anxiety

Review and practice of techniques for coping with anxiety (relaxation training, mental rehearsal, deep breathing, identifying and overcoming irrational/negative thought patterns)

Communication

Review and practice of skills for verbal and nonverbal communication (sending and receiving skills, active listening, the use of paraphrasing to avoid misunderstandings)

skills

Review and practice of skills for overcoming shyness, greetings, brief social exchanges; review and practice of basic conversational skills

Social skills

Assertiveness

A

Review of situations calling for an assertive response, practice of verbal and nonverbal skills

Assertiveness

B

Review and practice of refusal skills for resisting peer pressures to smoke, drink, or use marijuana; identifying and avoiding high-risk situations

Review/General

marijuana.

Review of the basic principles and techniques of the LST Booster Sessions

problem solving

A brief description

of the eighth

grade booster

curriculum

is provided

in Table

1.

Provider selection and training The peer leaders and teachers who implemented the booster intervention were selected and trained using the same procedures that were used in the first year of this study. Training for

Substance

abuse prevention

51

both the peer leaders and teachers consisted of a four-hour training workshop conducted by members of the project staff. The workshop was modeled on that provided for the first year of the prevention program (Botvin, Baker, Renick et al., 1984). Included was a brief summary of the background and rationale for the intervention approach, a general overview of the curriculum, implementation guidelines, and demonstrations of selected classroom exercises. In addition, peer leaders participated in a series of briefing sessions which provided them with more specific preparation for each upcoming session. Teachers and peer leaders were provided with a curriculum containing detailed lesson plans for each of the booster sessions in order to facilitate standardized program implementation. Measures

The primary dependent variables used to evaluate the effectiveness of the prevention program were self-reported smoking, drinking, and marijuana use behaviors. Additionally, several cognitive, attitudinal, and personality variables hypothesized to be related to the initiation of substance use were also examined. The measures used to assess these variables are described below. Smoking status. Smoking status was determined by means of three dichotomous self-report measures: a monthly recall measure, a 7-day (weekly) recall measure, and a 24-hour (daily) recall measure. The monthly recall measure provides a means of detecting even relatively infrequent smoking, whereas the weekly and daily measures provide a means of detecting more regular smoking. In addition, smoking frequency was assessed by means of a five-point scale with response levels ranging from “never” to “everyday.” Because previous research has raised questions concerning the validity of self-reported smoking status in junior high school students (Evans et al., 1977; Hurd et al., 1980), steps were taken to ensure the collection of high quality self-report data. First, student ID codes were utilized rather than names to facilitate following each student throughout the course of the study while at the same time emphasizing the confidential nature of the questionnaire. Second, saliva samples were collected immediately prior to the section of the questionnaire dealing with self-reported smoking status. Such a procedure has been found to increase the accuracy of self-reports (Evans et al., 1977). Alcohol use. Several measures were used to assess the drinking of alcoholic beverages. Two dichotomous (yes/no) items were used to assess whether respondents drank alcohol, in the past month or week. In addition, three continuous measures were used to assess drinking frequency, amount consumed per occasion, and episodes of drunkenness. Drinking frequency was assessed on a five-point scale ranging from never (1) to every day (5). The amount of alcohol consumed per occasion was assessed using a five-point scale which included the following choices: 1 drink, 2 drinks, 3 to 6 drinks, more than 6 drinks, or until getting high or drunk. The frequency of drunkenness was measured by a six-point scale which included the following choices: never, once or twice a year, once or twice a month, once or twice a week, several times a week, or almost every day. Marijuana use. Marijuana use status was determined by means of four dichotomous (yes/no) self-report measures which assess whether respondents had ever tried marijuana or had used it in the past month, past week, and past day. The first two recall measures provide a means of detecting even relatively infrequent marijuana use, whereas the measure of use in the past week and past day provide a means of detecting more regular marijuana use. In addition, marijuana use status was assessed using a five-point scale with response categories ranging from never to everyday. Cognirive measures. In order to measure changes in knowledge resulting from the prevention program, 30 true-false items were included in the questionnaire. These items were

52

GILBERT J. BOTVIN et al.

designed to measure changes in knowledge relating to the prevalence of tobacco, alcohol, and marijuana use among both adults and teenagers as well as knowledge concerning the potential negative health and social consequences of using these substances. Attitudinal measures. Students’ attitudes about tobacco, alcohol, and marijuana use, the characteristics of users, and the social benefits of using these substances were assessed by means of an 33-item scale. The 12 smoking attitude items have been used previously in our smoking prevention research and were derived from The Teenagers Self-test: Cigarette Smoking (U.S. Public Health Service, 1974). Parallel items were used to assess attitudes toward alcohol use (10 items) and marijuana use (11 items). The items contained in the attitude scale used in this study were selected from a longer list of items based on their age-appropriateness and their ability to discriminate between users and nonusers of these substances. Personality measures. A number of personality variables were assessed using several different scales. Assertiveness was measured using a shortened (20-item) version of the Assertion Inventory (Gambrill & Richey, 1975). Locus of control was measured by means of the 24-item Norwicki-Strickland Locus of Control Scale for Children (1973). Social anxiety was measured by means of seven situation-specific items relating to common social situations which might produce anxiety (e.g., giving and receiving compliments, expressing feelings, initiating a conversation). Self-esteem was measured using self-ratings in response to 10 descriptive adjectives (e.g., smart, popular, good-looking) in a manner typical of most measures of self-esteem (Wells & Marwell, 1976). Self-confidence and self-satisfaction were measured using three descriptive statements each (e.g., “I am able to handle difficult situations,” “I am generally satisfied with myself”). Smoking influenceability was measured using three items concerning the respondent’s probability of yielding to social pressure to smoke. General influenceability was measured using five items concerned with the extent to which the respondent is typically influenced by others when making an important decision. With the exception of locus of control, all of the personality variables were measured using five-point Likert-type scales. Furthermore, all these items have been used in our previous research and have test-retest reliabilities ranging from .66 to .78 (Botvin & Eng, 1982). Data analysis Data from this follow-up were analyzed according to the following plan using SAS (1985). First, data were analyzed to test for any potential bias in this follow-up sample resulting from differential attrition using a series of 2 X 5 ANOVAs (pretest use status X condition). Both main effects and interaction effects were computed. Second, the experimental and control conditions were compared for the entire follow-up sample with respect to substance use behavior and mediating variables using the general linear models (GLM) procedure described by Overall (1980). A series of 2 x 5 GLM analyses (sex x condition) were computed with pretest values being used as covariates. Planned comparisons (t tests) of covariate adjusted means were used to determine significant pairwise contrasts. Third, a restricted sample of students whose teachers were judged by field staff to have implemented the intevention with a reasonably high degree of fidelity were compared with control students in terms of substance use behavior and mediating variables. To compare the students in the restricted high implementation teacher group with control students, a series of 2 X 2 GLM analyses (sex x condition) were computed with pretest values being used as covariates. RESULTS

Attrition analysis Previous studies have indicated

that higher attrition

may occur among substance

users,

Substance

Table 2. Covariate

adjusted one-year

53

abuse prevention

follow-up response proportions marijuana use

Variables

Peer

Peer booster

Smoking Month Week Day Index

.31 .22 .I7 .98

.12** .05** .03** .40**

Teacher

for tobacco,

alcohol,

Teacher booster

and

Control

.26 .16 .ll .75

.34 .21 .16 1.08

.23 .16 .13 .74

Alcohol Month Week Frequency index Amount index Drunkenness index

.40 .19 2.05 2.21 1.76

.39 .18 2.04 1.80* 1.57

.39 .18 2.11 2.19 1.69

.5.5 .33 2.32 2.14 1.83

.38 .20 2.03 2.19 1.78

Marijuana bver Month Week Day Index

.25 .09 .06 .02 1.25

.14 .05* .02 .02 1.12*

.21 .I1 .08 .04 1.32

.29 .16 .09 .05 1.42

.21 .13 .07 .04 1.31

*p i .05. **p < .Ol.

(e.g., Hansen, Collins, Malotte, Johnson, & Fielding, 1985). In view of the observed attrition in this sample, a 2 x 5 ANOVA (pretest use status x conditions) was conducted for each dependent variable (using the monthly recall measures) to determine the extent to which differential attrition might be present. Analyses of pretest use status indicated that there was no differential attrition between smokers and nonsmokers, F (1, 1296) = 2.96, ns. However, significantly greater attrition was found among students who reported drinking on the pretest than and among those who did not, F (1,1304) = 5.76, p < 0.02 among students who reported using marijuana on the pretest, F (1, 1022) = 7.85, p-C 0.005. No significant condition X pretest use status interaction were found for smoking, drinking, or marijuana use. Thus, although some attrition was evident in this follow-up sample, it was not judged to have threatened the internal validity of this study. Substance

use behavior

Table 2 contains the covariate adjusted one-year follow-up proportions for tobacco, alcohol, and marijuana. These data were analyzed using the general linear models (GLM) approach described by Overall (1980). One-year follow-up response frequencies were compared for each of the five conditions, with pretest response frequencies being used as covariates. Both sex and condition were included as factors in the analysis. Smoking behavior. Significant main effect were found for the monthly recall measure of cigarette smoking, F (4, 968) = 6.32, p < 0.0001; for the weekly measure of cigarette smoking, F (4, 956) = 5.23, p -=c0.0004; for the daily measure of cigarette smoking, F (4, 950) = 4.45, p < 0.002; and the index measure of smoking frequency, F (4, 950) = 8.99, p < 0.0001. Planned comparisons using t tests indicated that there was a significantly lower proportion of smokers in the peer-led booster condition when compared to the control condition for the monthly measure @ < 0.02), the weekly measure @ < O.OOS), the daily measure (p < O.OOS), and the smoking index (p < 0.005). There were also significantly fewer students in the peer booster condition reporting

54

GILBERT J. BOTVIN et al

cigarette smoking than in the teacher booster condition on the monthly measure (p < O.OOOl), the weekly measure (p < O.OOOl), the daily measure (p < O.OOOS), and the smoking index (p < 0.0001); significantly fewer students in the peer booster condition reporting smoking than in the peer non-booster condition for the monthly smoking measure 0, < 0.0002), the weekly measure (p < O.OOOl), the daily measure (p < 0.0002), and the smoking index @ < 0.0001); and significantly fewer students in the peer booster condition reporting smoking than in the teacher non-booster condition using the monthly measure (p < 0.002), the weekly measure (p < 0.002), the daily measure @ < 0.02), and the smoking index @ < 0.002). In general, these analyses revealed that the teacher booster condition had the highest proportion of cigarette smokers. In addition to the peer booster condition, both the teacher non-booster condition (p < 0.03) and the control condition @ < 0.01) had fewer smokers based on the monthly measure than the teacher booster condition; and the teacher non-booster condition (p < 0.0006) and the control condition (p < 0.001) were significantly lower than the teacher booster condition in terms of the smoking index. Murijuana use. Significant main effects were also found for the monthly recall measure of marijuana use, F (4, 948) = 2.49, p < 0.05 and for the marijuana use index, F (4, 929) = 3.09, p < 0.02. Planned comparisons indicated that there was a significantly lower proportion of students in the peer-led booster condition reporting marijuana use than in the control condition on the monthly recall measure (p < 0.03) and on the index measure of marijuana use (p < 0.03). The peer-led booster condition also had significantly fewer students reporting marijuana use than the teacher booster condition for the monthly recall measure (p < 0.003), the weekly recall measure (p < 0.03), and the marijuana index (p < 0.0007). Finally, there were significantly fewer students in the peer non-booster condition reporting marijuana used based on the marijuana use index than in the teacher booster condition @ < 0.05). Alcohol use. There were significant main effects for drinking behavior using the monthly measure, F (4, 975) = 4.98, p < 0.001; the weekly measure, F (4, 949) = 5.04, p < 0.0005; and the drinking frequency index, F (4, 941) = 4.36, p < 0.002. For all three measures the teacher booster condition produced the worst results. The peer booster condition had significantly fewer drinkers than the teacher booster condition using the monthly measure @ < .002), the weekly measure (p < .002), and had lower scores on the drinking frequency index (p < .002). The peer non-booster condition also had significantly fewer drinkers than the teacher booster condition using the monthly measure (p < O.OOS), the weekly measure (p < 0.002), and had a lower score on the drinking frequency index (p -C 0.003). The teacher non-booster condition had significantly fewer drinkers using the monthly measure (p < O.OOOl), the weekly measure (p < O.OOOl), and had lower scores on the drinking frequency index @ < 0.004). Even the control group had significantly fewer drinkers than the teacher booster group based on the monthly measure (p < O.OOOl), the weekly measure 0, < O.OOl), and had a lower score on the drinking frequency index (p < 0.0002). Although no main effects were evident, the peer booster condition reported consuming less alcohol per occasion than the students in the control group (p < O.OS), the teacher non-booster group (p < 0.03), and the teacher booster group (p < 0.06). Summary of behavioral effects. It is, therefore, clear from this data that the peer booster condition produced significantly better results in terms of tobacco, alcohol, and marijuana use than the control condition, and in most cases was superior to the other three intervention conditions. On the other hand, it is also clear that the teacher booster condition produced results which were as bad and, in some instances even worse, than the control condition.

Substance

Table 3. Covariate

adjusted one-year follow-up

Variable Knowledge Tobacco Alcohol Marijuana

55

abuse prevention

means for knowledge,

attitude, and personality

Peer

Peer booster

Teacher

Teacher booster

1.95**** 7.47** 6.46

8.50**** 7.10**** 6.11

7.36*** 1.15 5.14

8.55**** 7.16 6.36

variables

Control

6.74 1.04 6.30

Attitudes Tobacco Alcohol Marijuana

31.84 40.42 45.81

38.95** 40.54 46.38

38.29* 40.03 45.03

37.19 38.36 43.39

37.29 39.60 45.20

Personality Asserttveness Locus of control Social anxiety Self-esteem Smoking influenceability General influenceability

68.43 1.53 20.22 31.82 7.66 13.01

69.62 6.68** 19.41 31.62 7.41 13.23

69.11 1.69 19.90 38.40 7.56 13.22

67.68 8.19 20.21 37.21 7.68 13.31

68.71 7.11 20.01 31.98 1.66 12.68

*p < .05. **p < .Ol. ***p < ,001. ****p < .OOOl.

Mediating variables Table 3 presents the covariate adjusted means for the cognitive, attitudinal, and personality variables broken down by condition. In order to present a coherent and logical description of these results, all of the main effects are presented first, followed by the results of planned comparisons between each treatment condition and the control condition. The last section presents planned comparisons between each of the treatment conditions to examine their relative effectiveness. Main effects. Significant main effects were found for smoking knowledge, F (4, 954) = 27.91, p < 0.0001; drinking knowledge, F (4, 970) = 5.35, p < 0.0003; marijuana knowledge, F (4, 918) = 9.53, p < 0.0001; smoking attitudes, F (4, 959) = 3.87, p < 0.004; drinking attitudes, F (4, 970) = 3.23, p < 0.01; marijuana attitudes, F (4, 877) = 3.04, p < 0.02, and locus of control, F (4, 866) = 3.99, p < 0.003. Experimental and control comparisons. Planned comparisons of the experimental conditions against the control condition indicated that all four experimental conditions had significantly higher smoking knowledge scores than the control condition @ < 0.0001); the peer-led booster condition @ < 0.0001) and the peer-led non-booster condition (p < 0.01) had significantly higher drinking knowledge scores than the control condition; the peer-led booster condition @ < O.OOOl), the peer-led non-booster condition (p < 0.001) and the teacher-led booster condition 0, < 0.0001) had significantly higher scores on marijuana knowledge than the control condition. Both the peer-led booster condition (p < 0.001) and the teacher-led non-booster condition (p < 0.01) had significantly higher smoking attitude scores than the control condition. However, two unexpected effects were found for both drinking and marijuana attitudes. The teacher-led booster condition had significantly lower (more positive) drinking attitudes (_D< 0.04) and marijuana use attitudes @ < 0.02) than the control condition. Finally, the peer-led booster condition had significantly lower (more internal) locus of control scores than the control condition @ < 0.01). Comparisons within experimental conditions. The relative effectiveness of the four

56

GILBERT J. BOTVIN et al.

treatment conditions was also compared for each of the cognitive, attitudinal, and personality mediating variables. Planned comparisons indicated that the peer-led booster condition had significantly higher smoking knowledge follow-up scores than either the peer-led nonbooster condition (p =C 0.04) or the teacher-led non-booster condition (p < 0.0001). The teacher-led booster condition had significantly higher smoking knowledge follow-up scores than either the teacher-led non-booster condition (p < 0.0001) or the peer-led non-booster condition (p < 0.01). Finally, the peer-led non-booster condition had significantly higher smoking knowledge scores than the teacher-led non-booster condition (JJ < 0.01). Planned comparisons for drinking knowledge indicated that the peer-led booster condition had significantly higher follow-up scores than either the teacher-led booster condition (p < 0.002) or the teacher-led non-booster condition @ =C0.0006); and the peer-led non-booster condition had significantly higher scores than the teacher-led non-booster condition @ < 0.04). Planned comparisons for marijuana knowledge indicated that the peer-led booster condition @ < O.OOOl), the teacher-led booster condition (p -C 0.006), and the peer-led non-booster condition 0, < 0.01) had significantly higher follow-up scores than the teacher-led non-booster condition. Planned comparisons for smoking attitudes indicated that the peer-led booster condition had significantly higher follow-up scores than the teacher-led booster condition @ < 0.004) which had significantly higher scores than the teacher-led non-booster condition @ < 0.02). Planned comparisons for drinking attitudes indicated that the teacher-led booster condition had significantly lower (more positive) drinking attitudes than the peer-led booster condition (p < 0.002). Planned comparisons for marijuana attitudes indicated that the teacher-led booster condition had significantly lower (more positive) marijuana attitudes than the peer-led booster condition 0, -C 0 .OOl), the peer-led non-booster condition (p -=c0.004)) and the teacher-led non-booster condition (p < 0.02). Finally, planned comparisons indicated that the peer-led booster condition had significantly lower (more internal) locus of control scores than the teacher-led booster condition (p < O.OOOl), the peer-led non-booster condition 01 < 0.04), and the teacher-led non-booster condition 0, < 0.004). Substance use behavior: Restricted sample Since observations by field staff indicated that the intervention was implemented with a low degree of fidelity by many teachers, additional analyses were conducted to determine the effectiveness of the intervention when implemented by teachers with a reasonable degree of fidelity. All teachers were rated by a member of the field staff who had observed implementation of the intervention. Teachers were rated on a scale from one to five in terms of the extent to which they had implemented the prevention program with fidelity to the intervention protocol. A restricted sample was then formed consisting of only those students whose teacher received a rating of either four or five. The resulting restricted sample consisted of 145 eighth graders at the one-year follow-up. The retention rates were identical for the restricted teacher-led group (80%) and the control group which had 227 (80%) at the one-year follow-up. Tables 4 and 5 present data derived from this restricted sample. The student group (n = 372) in the data set used for the one-year follow-up with this restricted sample consisted of half males and half females. In addition, the sample was 29% black, 69% white, 4% hispanic, 2% oriental and 4% other. The students in this sample came from intact families (80%), and had mothers (69%) and fathers (72%) who attended college or graduate school. Significant main effects were found for sex using the monthly smoking measure, F (1,

Substance

Table 4. Covariate

abuse prevention

adjusted one-year follow-up Restricted sample

response proportions:

Teacher Smoking Month Week

.23 12*8 .08*a .62*&

Control

.24 .17 .13 .76

Day Index Alcohol Month Week Frequency index Amount index Drunkenness index

.31 .11* 1.94 1.92 1.50*

.36 .20 1.95 2.25 1.82

Marijuana Ever Month Week Day Index

. 19*a .09 .Ol .05 1.28

.21 .13 .07 .04 1.31

“Sex x condition *p < .05.

interaction.

363) = 14.04, p < 0.0002 and the weekly smoking measure, F (1, 357) = 10.10, p < 0.002. Moreover, there was a sex x condition interaction for the weekly smoking measure which approached significance, F (1, 357) = 3.59, p < 0.06. Preplanned comparisons indicated that there was a significantly higher proportion of smokers among the females in the control group than among the females in the teacher-led group @ < 0.02), the males in the teacher-led group @ < 0.002), or the males in the control group (p < 0.0001). Significant main effects were also found for sex using the daily recall measure of smoking,

Table 5. Covariate adjusted one-year follow-up means for knowledge, attitude and personality variables: Restricted sample Teacher Knowledge Tobacco Alcohol Marijuana

1.76**** 7.04 5.62

Control

6.76 7.05 6.29

Attitudes Tobacco Alcohol Marijuana

38.56** 40.49 46.11

37.08 39.54 45.01

Personality Asserttveness Locus of control Social anxiety Self-esteem Smoking influenceability General influenceability

69.91 8.06 19.89 39.08 1.54 13.51

68.06 1.96 19.99 38.37 7.66 12.70

**p < .Ol. ****p < .OOOl

58

GILBERT J. BOTVIN et al.

F (1, 357) = 8.29, p < 0.005; a nearly significant main effect for condition, F (1, 357) = 2.95, p < 0.09; and a nearly significant sex x condition interaction, F (1, 357) = 3.01, p < 0.08. Preplanned comparisons indicated that there were significantly more females in the control group who reported smoking using the daily measure than females in the teacher-led prevention condition (p < O.Ol), males in the teacher-led prevention condition @ < 0.002), and males in the control condition (p < 0.0003). Significant main effects were also found for sex using the smoking index, F (1, 350) = 17.85, p < 0.0001; and sex X condition interaction effects, F (1, 350) = 4.18, p < 0.04. Once again, there was significantly more smoking among the females in the control group than among females in the teacher-led prevention condition (p < 0.02), the males in the teacher-led prevention condition (p < 0.0002), and the males in the control condition @ < 0.0001). Significantly fewer students in the teacher-led condition than in the control condition reported drinking based on the weekly recall measure, F (1, 353) = 4.92, p < 0.03. Preplanned comparisons indicated that there were significantly fewer girls in the teacher-led condition (p < 0.04) who reported drinking during the past week than in the control group. Students in the teacher-led condition also reported significantly fewer episodes of drunkenness than the students in the control condition, F (1, 140) = 4.82, p < 0.03. Preplanned comparisons indicated that the females in the teacher-led group had significantly fewer episodes of drunkenness than the males in the control group (p < 0.03). No significant main effects were found for sex or condition with respect to whether or not students had ever tried marijuana. However, a significant sex x condition interaction was found, F (1, 351) = 5.89, p < 0.02. Planned comparisons indicated that there were significantly fewer females in the teacher-led condition than in the control condition (p < 0.03) who had ever tried marijuana. Mediating variables: Restricted sample At the time of the one-year follow-up, students in the restricted teacher-led condition had significantly higher smoking knowledge scores than the control students, F (1, 357) = 20.45, p < 0.0001, and significantly lower general influenceability scores, F (1, 334) = 4.85, p < 0.03. The students in the teacher-led group also had more anti-smoking attitudes than the students in the control condition, F (1, 352) = 6.37, p < 0.01. DISCUSSION

The results of this follow-up study provide additional support for the efficacy of this type of substance abuse prevention approach. The one-year follow-up results are similar to those obtained at the initial posttest (Botvin, Baker, Renick et al., 1984). The peer-led conditions continued to be more effective than the teacher-led conditions both in terms of substance use behavior and in terms of impacting on the cognitive, attitudinal, and personality mediating variables. Moreover, where prevention effects were found, the booster condition was superior to the non-booster condition. In fact, the peer-led booster condition was not only the most effective condition with respect to the mediating variables, but was the only condition to produce significant behavioral results. Furthermore, the magnitude of these effects was substantial. The peer-led booster condition had a 79% lower proportion of smokers when compared with the control condition using the weekly recall measure and a 82% lower proportion of smokers using the daily recall measure. Similar results were obtained with respect to marijuana use, with the peer-led condition having a 69% lower proportion of marijuana users based on the monthly measure,

Substance abuse prevention

and a 78% lower proportion

of marijuana

59

users based on the weekly measure.

Teacher and peer effects It has generally been assumed that peer-leaders have higher source credibility with adolescents than adults and, thus, it has been hypothesized by some investigators that peer-leaders would be the most effective prevention program providers. Indeed, the use of same-age or older peer leaders is a feature that has been evident in many of the newer social influence approaches to substance abuse prevention. While there is evidence supporting the efficacy of peer leaders for prevention strategies teaching social resistance skills (e.g., Arkin et al., 1981; Perry, Telch, Killen, Dass, & Maccoby, 1983), it is important to recognize that they generally have been used in an ancillary fashion rather than as primary program providers. In most to these studies, the primary providers have been either members of the research project staff or teachers. In our research with the life skills training approach, previous studies have indicated that reductions in cigarette smoking can be achieved when it is implemented by outside health professionals (Botvin et al., 1980), peer leaders (Botvin & Eng, 1982), and classroom teachers (Botvin et al., 1983); and that reductions in alcohol use can be achieved when it is implemented by regular classroom teachers (Botvin et al., 1983). Since our previous research had demonstrated that this type of intervention is effective when implemented by peer leaders and classroom teachers, one of the purposes of this study was to determine which type of program provider was more effective. However, in light of reports from field staff that many teachers failed to implement the prevention program according to the protocol and that some teachers simply failed to implement substantial portions of the intervention altogether, the failure of the teacher-led conditions to produce prevention effects was not entirely unexpected. What was unexpected was the finding that the teacher-led booster condition actually produced negative effects on some of the drinking measures. The results of the analyses conducted with the restricted sample of students whose teachers were judged to have implemented the intervention with fidelity and completeness were somewhat reassuring since the negative alcohol effects disappeared and positive effects emerged for tobacco, alcohol, and marijuana use. However, these effects were primarily evident only for female. There were 44% fewer female smokers in the teacher-led prevention condition than in the control group using the weekly recall measure and 50% fewer using the daily recall measure. Similarly, there were 51% fewer females reporting alcohol use in the past week in the teacher-led condition compared with the controls, and less problem drinking (i.e., fewer episodes of drunkenness) for both males and females among the students in the teacher-led group when compared with students in the control group. Finally, experimentation with marijuana was 47% lower among the females in the teacher-led prevention condition when compared with the females in the control condition. Intervention effects were evident for two of the presumed mediating variables (smoking knowledge and smoking attitudes). In view of the results obtained with the restricted teacher-led sample in this study and the results of previous research with this prevention strategy, it seems reasonable to conclude that this type of prevention program can be effective when implemented by regular classroom teachers. Implementation issues In this study, the positive effects of the intervention appear to have been masked in the initial analyses conducted with the full teacher-led sample because a majority of the teachers did not implement the intervention according to the protocol. The failure of such a large

60

GILBERT J. BOTVIN et al.

number of the teachers to adequately implement the prevention program raises several important questions. The first question concerns which portions of the intervention were implemented and which were not. The pattern of effects for the mediating variables suggests that most of the teachers did at least implement the cognitive portion of the curriculum, since students in the teacher-led conditions had scores that were roughly comparable to those found in the peer-led conditions and significantly higher than those obtained by the students in the control condition. On the other hand, the pattern of effects for the mediating variables and the limited information from field staff suggest that many teachers did not implement the skills training portion of the intervention. A second question concerns why the intervention was inadequately implemented by participating teachers. There are several possible reasons. The teachers in this study may not have been convinced that the approach being tested was as effective as teaching factual information about drugs and the adverse consequences of use, or they may have simply felt more comfortable using such an approach since few teachers have any training or experience in teaching cognitive-behavioral life skills. More extensive provider training may be necessary both to convince teachers of the merits of a cognitive-behavioral prevention strategy emphasizing psychosocial development and to provide them with the requisite skills and confidence for teaching this type of prevention curriculum. Another factor which may have undermined the effective implementation of the intervention was the fact that, unlike in past studies, we did not participate in the selection of the teachers nor establish any selection criteria for including teachers in the study. Instead, schools were permitted to select teachers using their own criteria. This resulted in many teachers simply being mandated to teach the prevention program after the school administration made the basic decisions concerning where the prevention program would be scheduled and who would teach it. In order to have this or any other intervention implemented effectively, it is obviously necessary to have enthusiastic, confident and adequately trained program providers. Implications for interventions targeted at alcohol use The unexpected finding of negative effects on some of the alcohol measures for the initial analyses of the teacher-led conditions deserves additional discussion. These negative effects were present both for some of the behavioral self-report measures and the measure of attitudes toward alcohol use. As was indicated elsewhere, these effects not only disappeared but were replaced by positive effects once the students whose teachers were not judged to have implemented the intervention with fidelity and completeness were eliminated from the analyses. While these findings and the findings of a previous study (Botvin et al., 1983) provide support for the efficacy of this approach for reducing alcohol use, questions remain concerning why negative effects emerged when the students in the low implementation teacher-led conditions were included in the analyses. A recent comprehensive review of the alcohol prevention literature by Moskowitz (in press) indicates that most prevention approaches are not effective and some may actually be counterproductive. For example, several studies evaluating approaches which emphasize “responsible use” have produced negative effects (presumably because they may communicate to students the message that is acceptable to drink as long as it is done in a responsible way). Other factors identified by Moskowitz in his review of the alcohol prevention literature which may inadvertently stimulate experimentation with alcohol include inadequate motivation and training on the part of program providers, inadequate implementation, ambiguous program goals, lack of an explicit anti-alcohol use message, and delivery to an inappropriate

Substance abuse prevention

61

target group. Furthermore, it seems logical to expect that provider attitudes which are either too permissive or too moralistic might have the potential for undermining even the most effective prevention program and producing undesired effects. While it is not possible to determine with any degree of certitude why negative effects were evident for the analysis conducted with the full sample, it is clear that particular care needs to be exercised in selecting providers to implement prevention approaches targeted at alcohol use. Equally clear is the need to develop effective quality control procedures to insure a high degree of implementation fidelity. Limitations This study has several limitations which should be noted. First, the unit of assignment to experimental condition was the school, while the unit of analysis was the individual student. Failure to maintain the unit of assignment/unit of analysis set, while common in school-based prevention research, has been criticized (e.g., Flay, 1985) because it permits the possible confounding of treatment effects with school effects. Unfortunately, as Cook (1985) has noted, there is no easy solution to this problem. Another limitation of this study concerns the generalizability of these findings from this sample to other populations. The results of this study are limited to those students who were present for the follow-up data collection. Thus, this study suffers from the same weakness of all school-based studies in that these results are only generalizable to other school populations. Moreover, it involved predominantly white, middle class students attending suburban schools and therefore cannot be generalized to other populations who may be at high risk for becoming tobacco, alcohol or drug users. Conclusions and future directions In summary, these one-year follow-up data indicate that this type of prevention strategy, when implemented by peer leaders in the seventh grade and when additional booster session are provided during the eighth grade, can reduce tobacco, alcohol, and marijuana use. Similar effects are evident for females when the prevention program is implemented with fidelity by classroom teachers. Moreover, the prevention program is also capable of producing a significant impact on several cognitive, attitudinal, and personality variables at the one-year follow-up. Additional follow-up is needed to determine the durability of these findings. Although the results of this study are promising with respect to the substances assessed, they do not address the larger question of the impact of this prevention approach to other forms of substance abuse. Additional research is necessary to determine the efficacy of this and other promising prevention approaches with other populations, particularly high risk populations, and with other drugs.

REFERENCES Arkin, R.M., Roemhild, H.J., Johnson, C.A., Luepker, R.V., & Murray, D.M. (1981). The Minnesota smoking prevention program: A seventh grade health curriculum supplement. Journal of School Healrh, 51 (19). 616-661. Berberian, R.M., Lovejoy, J., & Paparella, S. (1976). The effectiveness of drug education programs: A critical review. Health Education Monographs, 4, 377-398. Botvin, G.J., Baker, E., Botvin, E.M., Filazzola, A.D., & Millman, R.B. (1984). Alcohol abuse prevention through the development of personal and social competence: A pilot study. Journal of&dies on Alcohol, 45, 550-552. Botvin, G.J., Baker, E., Renick, N.L., Filazzola, A.D., & Botvin, E.M. (1984) A cognitive-behavioral approach to substance abuse prevention. Addictive Behaviors, 9, 137-147.

62

GILBERT .I. BOTVIN et al

Botvin. G.J., & Dusenbury, L. (1987). Life skills training: A psychoeducational approach to substance abuse prevention. In CA. Maher & J.E. Zins (Eds.), Psychoeducational interventions in schools: Methods and procedures for enhancing student competence. Elmsford, NY: Pergamon Press. Botvin, G.J., & Eng. A. (1980). A comprehensive school-based smoking prevention program. Journal of School Health, 50, 209-213. Botvin, G.J., Eng, A. (1982). The efficacy of a multicomponent approach to prevention of cigarette smoking, Preventive Medicine, 11, 199-211. Botvin, G.J., Eng, A., & Williams, C.L. (1980). Preventing the onset of cigarette smoking through life skills training. Preventive Medicine, 9, 135-143. Botvin, G.J., Renick, N.L., & Baker, E. (1983). The effects of scheduling format and booster sessions on a broad-spectrum psychosocial smoking prevention program. Journal of Behavioral Medicine, 6(4), 359-379. Botvin, G.J., & Tortu, S. (1988). Peer relationships, social competence, and substance abuse prevention: Implications for the family. Journal of Social Work and Human Sexual@, 6(2), 105-l 19. Braucht, G.N., Follingstad, D., Barkarsh, D., & Berry, K.L. (1973). Drug education: A review of goals, approaches, and effectiveness, and a paradigm for evaluation. Quarterly Journal of Studies on Alcohol, 34, 1279-1292. Cook, T. (1985). Priorities in research in smoking prevention. In C. Bell and R. Battjes (Eds.), Prevenrion research: Deterring drug abuse among children and adolescents (DHHS Publication No. ADM 85-1334) (pp. 196-220). Dom, N., & Thompson, A. (1976). Evaluation of drug education in the longer term is not an optional extra. Community Health, 7, 154-161. Evans, R.I. (1976). Smoking in children: Developing a social psychological strategy of deterrence. Preventive Medicine, 5, 122-127. Evans, R.I., Hansen, W.B., & Mittlemark, M.B. (1977). Increasing the validity of self-reports of behavior in a smoking in children investigation. Journal of Applied Psychology, 62, 521423. Evans, R.I., Rozelle, R.M., Mittlemark, M.B., Hansen. W.B., Bane, A.L., & Havis, J. (1978). Deterring the onset of smoking in children: Knowledge of immediate physiological effects and coping with peer pressure, media pressure, and parent modeling. Journal of Applied Social Psychology, 8, 126-135. Flay, B. (1985). Psychological approaches to smoking prevention: A review of findings, Health Psychology, 4, 449-488. Gambrill, E.D., & Richey, C.A. (1975). An assertion inventory for use in assessment and research. Behavior Therapy, 6, 550-561. Goodstadt, M.S. (1974). Myths and methodology in drug education: A critical review of the research evidence. In M.S. Goodstadt (Ed.), Research on methods and programs of drug education. Toronto: Addiction Research Foundation. Hansen, W.B., Collins, L.M., Malotte, C.K., Johnson, C.A., & Fielding, J.E. Attrition in prevention research. Journal of Behavioral Medicine, 8(3), 261-275. Luepker, R.V., Johnson, C.A., Murray, D.M., & Pechacek, T.F. (1983). Prevention of cigarette smoking: Three year follow-up of educational programs for youth. Journal of Behavioral Medicine, 6(l), 53-61, McAlister, A., Perry, C., & Maccoby, N. (1979). Adolescent smoking: Onset and prevention. Pediatrics, 63, 650-658. McAlister, A., Perry. C.L., Killen, J.. Slinkard, L.A., & Maccoby, N. (1980). Pilot study of smoking, alcohol, and drug abuse prevention. American Journal of Public Health, 70, 719-721. Moskowitz, J.M. (in press). The primary prevention of alcohol problems: A critical review of the research literature. Journal of Studies on Alcohol. Murray, D.M.. Johnson, C.A., Luepker, R.V., Pechacek. T.F., & Jacobs, D.R. (1980, September). Issues in smoking prevention research. Presented at American Psychological Association, Montreal. Norwicki, S., & Strickland, B.R. (1973). A locus of control scale for children. Journal of Consulting and Clinical Psyhology, 40, 148-154. Overall, J.E. (1980). Calculation of adjusted response frequencies using least squares regression methods. Applied Psychological Measurement, 4, 65-78. Pentz, M.A. (1983). Prevention of adolescent substance abuse through social skill development. In T.J. Glynn, C.G. Leukefeld, & J.P. Ludford (Eds.), Preventing adolescent drug abuse: Intervention strategies. Washington, DC: NIDA Research Monograph No. 47 (pp. 195-232). Perry, C.L., Telch, M.J.. Killen, J., Dass, R.. & Maccoby, N. (1983). High school smoking prevention: The relative efficacy of varied treatments and instructors. Adolescence, 18, 561-566. Perry, C.L., Killen, J., Slinkard, L.A., & McAlister, A. (1980). Peer teaching and smoking prevention among junior high students. Adolescence, 9, 277-281. Richards. L.G. (1969). Government programs and psychological principals in drug abuse education. Paper presented at Annual Convention of American Psychological Association, Washington, DC. SAS Institute, Inc. (1985). SAS for personal computers (6th ed.). Gary, NC: Author. Schaps, E., Bartolo, R.D., Moskowitz, J., Palley, C.S., & Churgin, S.A. (1981. winter). Review of 127 drug abuse prevention program evaluations. Journal of Drug Issues, Inc., 17113. Schinke, S.P. (1984). Preventing teenage pregnancy. In M. Hersen, R.M. Eisler, & P.M. Miller (Eds.). Progress in behavior modijicarion (Vo1.16. 31-63. New York: Academic.

Substance

abuse prevention

63

Schinke, S.P., & Blythe, B.J. (1981). Cognitive-behavioral prevention of children’s smoking. Child Behavior Therapy, 3, 25-42. Schinke, S.P., Gilchrist, L.D. (19830. Survey and evaluation methods: Smoking prevention among children and adolescents. In J. Grabowski & C.S. Bell (Eds.), Measurement in the analysis and treatment of smoking behavior (pp. 96-104). Washington, DC: U.S. Government Printing Office. Schinke, S.P., & Gilchrist, L.D. (19840). Life skills counseling wifh adolescenrs. Baltimore: University Park Press. Swisher, J.D., & Hoffman, A. (1975). Information: The irrelevant variable in drug education. In B.W. Corder, R.A. Smith, IQ J.D. Swisher, (Bds.), Drug abuse prevenrion: Perspectives and approaches for educators (pp. 49-62). Dubque, IA: William C. Brown. Swisher, J.D., Crawford, J.L., Goldstein, R., & Yura, M. (1971). Drug Education: Pushing or preventing? Peabody General of Education, 49, 68-75. Telch, M.J., Killen, J.D., McAlister, A.L., Perry, C.L., & Maccoby, N. (1982). Long-term follow-up of a pilot project on smoking prevention with adolescents. Journal of Behavioral Medicine, 5, 1-8. U.S. Public Health Service. (1974). Teenager’s self-test: Cigarette smoking. Bureau of Health Education, Center for Disease Control. US Department of Health, Education, and Welfare. Washington, DC, 1974. Wells, L., & Marwell, G. (1976). Selfesreem: Its conceptualizafion and measurement. Beverly Hills, CA: Sage Publication.