摘要：Objectives. To evaluate effects of 2 alcohol prevention interventions—Communities Mobilizing for Change on Alcohol (CMCA), a community organizing intervention designed to reduce youth alcohol access, and CONNECT, an individual-level screening and brief intervention approach—on other drug use outcomes. Methods. We conducted a community intervention trial with quarterly surveys over 3 years (2012–2015) of high school students living within the jurisdictional service area of the Cherokee Nation in Oklahoma. We used generalized estimating equations and linear probability models to examine intervention spillover effects on other drug use. Results. We found significant reductions in drug use other than alcohol attributable to CMCA and CONNECT. CMCA was associated with a 35% reduction in chewing tobacco use, a 39% reduction in marijuana use, and a 48% reduction in prescription drug misuse. CONNECT was associated with a 26% reduction in marijuana use and a 31% reduction in prescription drug misuse. Conclusions. Nonalcohol drug use was consistently reduced as a result of 2 theoretically and operationally distinct alcohol prevention strategies. Evaluations of alcohol prevention efforts should continue to include other drug use to understand the broader effects of such interventions. Alcohol is the most used drug by adolescents, followed by marijuana and tobacco. Polysubstance use is common, with more than a third of adolescents reporting recent use of both alcohol and marijuana or use of alcohol, marijuana, and cigarettes. 1 Among users of both substances, alcohol and marijuana are more likely to be used concurrently than alone. 2 Concurrent use of tobacco, alcohol, or other drugs is a concern because use of one influences consumption of the other and leads to negative health outcomes and reduced rates of cessation. 3 Polysubstance use among adolescents is strongly associated with substance use problems, including substance use disorder diagnoses, 1 particularly among American Indian youths (with 21% prevalence of polysubstance use). 4 In addition to epidemiological data showing co-occurrence of alcohol and other drug use, both the intervention and the economic literature point to the possibility of spillover effects of alcohol prevention on other drugs. A previous alcohol prevention trial of White rural adolescents found that the intervention reduced alcohol, cigarette, and marijuana use among youths who had not initiated alcohol use by age 12. 5 However, 2 recent meta-analyses found no evidence that alcohol-specific screening and brief interventions affect other drug use. 6 The economic literature reflects some disagreement on whether alcohol and other drugs act as complements or substitutes, although our read of the epidemiological and economic literature suggests a preponderance of evidence for complementarity. 7–9 We previously presented results from a randomized trial of 2 alcohol prevention strategies among youths in the Cherokee Nation. 10 Both Communities Mobilizing for Change on Alcohol (CMCA), a community organizing intervention designed to reduce youth alcohol access, and CONNECT, an individual screening and brief intervention strategy, were effective in reducing adolescent alcohol use and related consequences. Given the prevalence of early-onset polysubstance use, simultaneous use patterns, and important health sequelae of polysubstance use, we evaluated possible spillover effects of CMCA and CONNECT on other drug use.
