The effectiveness of a school-based substance abuse prevention program: 18-month follow-up of the EU-Dap cluster randomized controlled trial.

AIM: To evaluate the effectiveness of a school-based substance abuse prevention program developed in the EU-Dap study (EUropean Drug Addiction Prevention trial). MATERIALS AND METHODS: Cluster Randomized Controlled Trial. Seven European countries participated in the study; 170 schools (7079 pupils 12-14 years of age) were randomly assigned to one of three experimental conditions or to a control condition during the school year 2004/2005. The program consisted of a 12-h curriculum based on a comprehensive social influence approach. A pre-test survey assessing past and current substance use was conducted before the implementation of the program, while a post-test survey was carried out about 18 months after the pre-test. The association between program condition and change in substance use at post-test was expressed as adjusted prevalence odds ratio (POR), estimated by multilevel regression models. RESULTS: Persisting beneficial program effects were found for episodes of drunkenness (any, POR=0.80; 0.67-0.97; frequent, POR=0.62; 0.47-0.81) and for frequent cannabis use in the past 30 days (POR=0.74; 0.53-1.00), whereas daily cigarette smoking was not affected by the program as it was at the short-term follow-up. Baseline non-smokers that participated in the program progressed in tobacco consumption to a lower extent than those in the control condition, but no difference was detected in the proportion of quitters or reducers among baseline daily smokers. CONCLUSION: The experimental evaluation of an innovative school curriculum based on a comprehensive social influence approach, indicated persistent positive effects over 18 months for alcohol abuse and for cannabis use, but not for cigarette smoking.

The effectiveness of a school-based substance abuse prevention program: EU-Dap cluster randomised controlled trial.

OBJECTIVE: To evaluate the effectiveness of the school-based drug abuse prevention program developed in the EU-Dap study (EUropean Drug Abuse Prevention trial) in preventing the use of tobacco, alcohol and drugs at the post-test. METHODS: Cluster Randomised Controlled Trial. Seven European countries participated in the study; 170 schools (7079 pupils 12-14 years of age) were randomly assigned to one of three experimental conditions or to a control condition during the school year 2004/2005. A pre-test survey assessing past and current substance use was conducted before the implementation of the program. The program consisted in 12-hour class-based curriculum based on a comprehensive social-influence approach. A post-test survey was carried out in all participating schools, 3 months after the end of the program. The association between program condition and change in substance use at post-test was expressed as adjusted Prevalence Odds Ratio (POR), estimated by multilevel regression model. RESULTS: Program effects were found for daily cigarette smoking (POR=0.70; 0.52-0.94) and episodes of drunkenness in the past 30 days (POR=0.72; 0.58-0.90 for at least one episode, POR=0.69; 0.48-0.99 for three or more episodes), while effects on Cannabis use in the past 30 days were of marginal statistical significance (POR=0.77; 0.60-1.00). The curriculum was successful in preventing baseline non-smokers or sporadic smokers from moving onto daily smoking, but it was not effective in helping baseline daily smokers to reduce or stop smoking. CONCLUSION: School curricula based on a comprehensive social-influence model may delay progression to daily smoking and episodes of drunkenness.

Testing anonymous link procedures for follow-up of adolescents in a school-based trial: the EU-DAP pilot study.

OBJECTIVE: To study the feasibility of an anonymous coding procedure linking longitudinal information in a multi-center trial of substance abuse prevention among adolescents. METHODS: A school-based survey with re-test procedure was conducted among 485 students (mean age 13.8 years) from three countries at four study centers in order to study accuracy and repeatability of a self-generated anonymous code. RESULTS: Errors affected 18% of codes and 3% of all digits required for the code generation, with highest figures for two of the seven generation items. Sixty-one percent of the codes generated at the test were repeated identically at the re-test. Seventy-six percent of the codes could be linked excluding the 2 digits with the highest error rate in code generation, while 92% were linked using the best combination of the remaining seven or six digits. There was substantial variation between the centers in the results. CONCLUSIONS: Self-generation of anonymous codes is a feasible, but not a very efficient procedure to link longitudinal data among adolescents. Easy derivation and iterative matching procedures are crucial for achieving high efficiency of this type of anonymous linkage.

VEdeTTE, a longitudinal study on effectiveness of treatments for heroin addiction in Italy: study protocol and characteristics of study population.

The aim of this study was to provide a methodological overview of the study design of the national evaluation large-scale study VEdeTTE and a description of the VEdeTTE study population and to compare enrollments with refusals and the study population with the overall clients at the National Health System (NHS) treatment centers. VEdeTTE is a longitudinal study of heroin addicts recruited in 115 NHS treatment centers in Italy, 1998-2001; 11,903 people were enrolled, 3876 refused to participate; data were analysed on 10,454. Information from refusals was compared to enrollments. The characteristics of the cohort were compared to those of all patients treated in 1999 in Italy. Refusals had a lower educational level and less regular occupational status than those enrolled. Fourteen percent of enrolled patients were women; heroin users in the VEdeTTE study were older than patients attending all NHS treatment centers in Italy; incident cases were less represented. The majority of participants had more than 8 years of education, 33.5% were regularly employed, and only 2% did not have a fixed address. Injectors were 72.3%; 40.6% had a previous overdose, and 14.3% had been imprisoned for life; 15.7% shared injection equipment during the previous 6 months. The proportion of participants reporting heroin use approximately halved from the beginning of the current treatment to the time of the interview. The VEdeTTE study is the biggest cohort of heroin addicts attending treatment centers in Europe. The Italian heroin-addicted population under treatment seems to have low level of education but good social integration. Compared with men, women show a higher severity. Participants show a beneficial effect of treatment.