Ennett and colleagues (1994) used a quasi-experimental research design to evaluate the effect of Drug Abuse Resistance Education (DARE) on initiation of drug use. The data used in this study comes from the Illinois DARE study, which was a convenience sample of 18 pairs of elementary schools in northern and central Illinois. These schools were matched closely on racial composition; number of English as a second language (or ESL) students; percentage of students from low-income families; and metropolitan status (i.e., urban, suburban, and rural). Six pairs of schools, 12 schools total, in urban and suburban areas were randomly assigned to DARE or the control condition. In the rural settings, six pairs of schools were assigned to DARE or the control condition using a nonrandom procedure to minimize travel time and accommodate DARE officers’ busy schedules in the more urban locations. DARE schools were selected out of schools already planning to implement the program. Comparison schools were drawn from nearby counties.
This resulted in 1,803 students participating in the pretest or baseline data collection. The first round of data collection, Wave One, occurred just before the implementation of DARE when students were in either the fifth or sixth grade. Wave Two happened right at the end of DARE programming. Waves Three and Four occurred one year after the pretest and two years after the pretest, respectively. By the end of data collection, students were in seventh or eighth grade. Analyses were conducted on students that were present and provided information for all four waves of data collection, reducing the sample size to 1,334 students.
The sample consisted of roughly one-third fifth graders and two-thirds sixth graders, 33 percent and 67 percent respectively, and was almost equally divided by gender, with 51 percent male. The majority of the sample (54 percent) was white, followed by African American (22 percent), and Hispanic (9 percent). Percentages for Native American, Asian, and “other” were not reported. Most children (67 percent) had both parents at home, and the sample was fairly evenly divided amongst the three different community types: 35 percent urban, 38 percent suburban, and 27 percent rural.
The data collected measured drug use behaviors as well as social and psychological variables believed to be related to drug use. Smoking cigarettes and drinking alcohol were the two behaviors focused on in this evaluation, as they are the two substances most commonly used by adolescents. Attitude toward general and specific (i.e., cigarettes, alcohol, marijuana) drug use, perceived benefits and costs of drug use, self-esteem, assertiveness, and peer-resistance skills comprise the social and psychological variables measured. Also collected and used in later analyses were sociodemographic variables, such as gender, race/ethnicity, community structure, and family type.
The researchers used a nested cohort strategy to analyze the collected data. The nested strategy takes into account that schools were randomly assigned to receive DARE, not individuals. Students within schools were followed over time as a cohort to assess the effects of DARE at each posttest wave of data collection. Ordinary least squares (OLS) and logistic regression were both used, depending on whether the dependant variable was continuous or categorical, respectively. In the logistic regression models, the effect of DARE is in adjusted odds ratios, and for the OLS models, the coefficients are reported.
Clayton, Cattarello, and Johnstone (1996) used a quasi-experimental design to determine the effectiveness of DARE on adolescent drug use. Of 31 elementary schools in Lexington, Ky., 23 were randomly assigned to receive DARE, and the remaining eight schools were selected as comparison groups. These eight comparison schools received drug education lessons, but they were not part of the DARE curriculum. Since these schools could not be classified as “no treatment,” the evaluation looked at the DARE program versus another drug education program.
Pretests/baseline measures were obtained before DARE lessons or the comparison drug program was given in the sixth grade. The first posttest was taken four months after the completion of DARE. Follow-up data collections occurred every year for five years, with most students in the tenth grade at the final wave.
The final sample was 2,071 students who completed all five waves of testing. This sample was 51 percent male, 75 percent white, 22 percent African American, and two percent of another race/ethnicity. Most students were 11 to 12 years of age at baseline, making them 16 to 17 years of age at the end of the study period. A total of 1,550 students were in the treatment (DARE) group, and 551 students were in the comparison group.
Drug use was measured as the frequency of use of cigarettes, alcohol, and marijuana in the past year. Students were asked how many cigarettes they had smoked, how many glasses of alcohol, and the number of times they had smoked marijuana in the past year. Drug-specific attitudes were measured, using a five-item scale to assess how negatively adolescents viewed drugs. General drug attitudes were measured, using a seven-item scale, with no specific drug mentioned in any of those questions. Peer pressure was measured with a nine-item scale that focused on the respondent’s ability to resist peer pressure. In addition, students were asked how many of their friends they believe use cigarettes, alcohol, and marijuana. This perceptional measure was included as an additional peer pressure measure.
Mixed effects regression models were used to determine the short-term and long-term effectiveness of DARE. This method accounts for the clustered or hierarchical nature of the data, which are students clustered within schools and sequential measurements clustered within an individual. Individual trajectories of drug use are modeled first, then variation in status and change between persons within schools, and lastly, variation between schools.