Alcohol and Tobacco Use Prevention

Preventing Alcohol Use
by National Institute of Health

(Page 4 of 6)

Several studies have tested the effect of the LST approach on alcohol use frequency, episodes of drunkenness, and heavy drinking. The first of these studies was conducted with 239 seventh graders from two comparable New York City public schools that were randomly assigned to experimental and control conditions. The intervention was modified to include material concerning the potential consequences of alcohol use, and where appropriate, skills were taught in relation to situations that might promote alcohol use. Although no effects were evident at the initial posttest, they emerged at the 6-month followup. Compared with students in the control group, significantly fewer students in the experimental group reported drinking in the past month, 73 percent fewer reported heavy drinking, and 79 percent fewer reported getting drunk at least once per month.

Preventing Alcohol and Marijuana Use

A larger study was subsequently conducted to replicate the first study's findings, to evaluate the LST approach as a strategy for preventing marijuana use in addition to tobacco and alcohol use, and to compare the effectiveness of LST when implemented by older (10th- and 11th-grade) peer leaders as opposed to classroom teachers. More than 1,300 seventh-grade students from 10 suburban New York junior high schools participated in the study. The schools were randomly assigned to the following: 1. a teacher-led prevention curriculum, 2. a peer-led prevention curriculum, 3. a teacher-led prevention curriculum and booster sessions, 4. peer-led prevention curriculum and booster sessions, or 5. no prevention curriculum.

At the end of the first year, students who participated in the LST program drank significantly less alcohol per drinking occasion and were drunk less often, with the students in the peer-led condition reporting less alcohol use than the students in both the teacher-led and control conditions. In addition, the program reduced experimental marijuana use by 71 percent for students in the peer-led condition and regular marijuana use by 83 percent. The LST program also affected several cognitive, attitudinal, and personality variables consistent with decreased risk of ATOD use.

Followup data collected 1 year after the end of the regular intervention showed that depending on the measure used, researchers found 79 to 82 percent fewer smokers in the peer-led booster group compared with the control group and 69 to 78 percent fewer marijuana users in the peer-led booster group compared with the control group. Although no effects were observed overall for the teacherled group, for students in teacher-led groups in which the teacher taught at least 60 percent of the program (high implementation fidelity group), there were 44 to 50 percent fewer smokers, 47 percent fewer experimenters with marijuana, and 51 percent fewer drinkers than in the control group.

Long-Term Effectiveness

Most studies that have demonstrated prevention effects have focused on short-term results. To determine the durability of ATOD abuse prevention in general, and the LST approach in particular, we conducted a 6-year randomized trial involving nearly 6,000 students from 56 public schools in New York State. Schools were randomly assigned to prevention and control conditions. Students in the prevention condition received the LST program in the seventh grade, with booster sessions in the eighth and ninth grades. Specially trained classroom teachers taught the prevention program. Prevention effects for tobacco and alcohol use were observed at the end of the intervention as well as at the end of the 12th grade. Followup results at the end of the 12th grade indicated that significantly fewer LST students reported smoking cigarettes during the past month and the past week and that significantly fewer students reported heavy smoking (one pack or more per day). Although researchers found no effects for drinking frequency, significantly fewer prevention students reported getting drunk one or more times per month, compared with students in the control group.

Even stronger prevention effects were found for students in the high implementation fidelity group. Significant prevention effects were found for monthly, weekly, and heavy cigarette smoking as well as for weekly marijuana use. Significant prevention effects were also found for several measures of alcohol use including monthly, weekly, and heavy drinking (consuming three or more drinks per drinking occasion) as well as for getting drunk one or more times per month.

To assess the effect of the program on more serious levels of ATOD involvement, researchers compared multiple drug use of intervention and control group students. At the end of 12th grade, the researchers found 44 percent fewer LST students than control students who had used tobacco, alcohol, and marijuana one or more times per month and 66 percent fewer LST students who reported using all three substances one or more times per week. The strongest prevention effects were found for the students who received the most complete implementation of the program, including booster sessions.

Finally, although the results showed prevention effects regardless of whether providers were trained at a formal training workshop with periodic feedback and consultation from project staff or through a training videotape, the strongest effects were produced by the teachers who attended annual training workshops and received ongoing support. Both the individual and the school showed prevention effects when used as the unit of analysis.

The results of long-term followup studies can be confounded by differential attrition. For example, when a greater proportion of ATOD users or people at risk for becoming ATOD users in one group cannot be followed up, unbalanced experimental and control groups occur with respect to ATOD use or risk. This phenomenon can undermine the initial (pretest) equivalence of the treatment and control groups and make it impossible to determine whether any observed followup effects result from intervention or from differential attrition. In this study, attrition rates were equivalent for treatment and control conditions, as were pretest levels of ATOD use for the final analysis sample, supporting the conclusion that the prevention effects resulted from the intervention and not from differential attrition or pretest nonequivalence.

About the Author

NIH is the nation's medical research agency - making important medical discoveries that improve health and save lives. The National Institutes of Health (NIH), a part of the U.S. Department of Health and Human Services, is the primary Federal agency for conducting and supporting medical research.