Effects of a school-based prevention program on European adolescents' patterns of alcohol use

PURPOSE: School-based substance abuse prevention programs are widespread but are rarely evaluated in Europe. We aimed to evaluate the effect of a new school-based prevention program against substance use on the frequency of alcohol consumption and alcohol-related problem behaviors among European students. METHODS: During the school year 2004-2005, a total of 7,079 students aged 12-14 years from 143 schools in seven European countries participated in this cluster randomized controlled trial. Schools were randomly assigned to either control (65 schools, 3,532 students) or to a 12-session standardized program based on the comprehensive social influence model (78 schools, 3,547 students). Alcohol use and frequency of alcohol-related problem behaviors were investigated through a self-completed anonymous questionnaire at baseline and 18 months thereafter. The association between intervention and changes in alcohol-related outcomes was expressed as odds ratio (OR), estimated by multilevel regression model. RESULTS: The preventive program was associated with a decreased risk of reporting alcohol-related problems (OR = .78, 95% confidence intervals [CI] = .63-.98), although this reduction was not statistically significant in the subgroup of 743 current drinkers at baseline. The risk for alcohol consumption was not modified by exposure to the program (OR = .93, 95% CI = .79-1.09). In the intervention group, nondrinkers and occasional drinkers at baseline progressed toward frequent drinking less often than in the control group. CONCLUSIONS: School curricula based on the comprehensive social-influence model can delay progression to frequent drinking and reduce occurrence of alcohol-related behavioral problems in European students. These results, albeit moderate, have potentially useful implications at the population level.