Evaluation of the effectiveness of a school-based cannabis prevention program

Feasibility and acceptability of a web-intervention to prevent alcohol and cannabis-impaired driving among adolescents in driver education

Background

Adolescents increasingly view cannabis as a substance with limited harm. Their propensity to engage in risky driving, combined with their relative driving inexperience, places adolescents at heightened risk for harm resulting from impaired driving. Driver education provides an opportunity to help prevent and reduce these risks, yet few interventions address cannabis-impaired driving, especially impairment from simultaneous use of both cannabis and alcohol.

Methods

We adapted a single-session primary care brief intervention (CHAT) for driver education programs. First, we conducted two focus groups with adolescents aged 15-17 years (n = 6; n = 5) enrolled in driver education programs. Their feedback was integrated into a prototype of an online intervention called webCHAT that focuses on preventing alcohol and cannabis-impaired driving. Next, we recruited a new sample of adolescents who user tested webCHAT (n = 8) and provided qualitative and survey feedback. We analyzed qualitative data using classic content analysis and grouped themes according to the feasibility and acceptability of webCHAT.

Results

Participants suggested that webCHAT should have adolescent narrators in short, informal, and interactive videos. In satisfaction surveys (n = 8), 88% of participants would recommend webCHAT to a friend and 88% reported that they learned helpful skills regarding impaired driving. General acceptability was also reflected in interviews (n = 6; 100% would recommend the intervention to a friend, 100% indicated overall positive impressions, and 67% stated it was easy to use). Participants reported that it was helpful to learn about the negative effects of both cannabis and alcohol on driving behavior, voicing that webCHAT would help adolescents make more informed decisions.

Conclusions

Soliciting adolescent perspectives is critical when developing interventions targeting cannabis use because of increasingly permissive attitudes and perceptions of minimal risk associated with use. The current study highlights how feedback can help increase both the feasibility and acceptability of interventions.

Bullying as a Risk Factor for Eating Disorder Behaviors Among Students: Secondary Analysis for a Cluster Randomized Controlled Trial

This study aimed to examine whether being a victim of bullying predicted body dissatisfaction and eating disorder behavior (EDB). In this study, we performed secondary analysis from a cluster randomized controlled trial among 5208 eight grade students from 73 public schools in three Brazilian cities. Data were collected in 2019 through an anonymous self-report questionnaire on bullying, body dissatisfaction, and EDB. We used factor analysis, multivariate linear regression, and multinomial logistic regression to verify whether being a victim of bullying during the baseline results in body dissatisfaction and EDB at the nine months follow-up for the control and intervention groups. Our results showed that being female (OR 1.41, 95% CI 1.22-1.63) is a risk factor for dissatisfaction by overweight. Bullying was not a predictor of body dissatisfaction; however, being a victim of bullying (β 0.40, 95% CI 0.35-0.46) is a predictor of having more EDB, independent of the exposure to the program. Therefore, bullying deserves attention in the school environment.

Study design to evaluate a web-intervention to prevent alcohol and cannabis-impaired driving and use among adolescents in driver education

BACKGROUND

Alcohol and cannabis are the most commonly used substances among adolescents in the U.S. The consequences related to using both substances together are significantly higher relative to use of either substance alone. Teens' propensity to engage in risky driving behaviors (e.g., speeding, rapid lane changes, and texting) and their relative inexperience with the timing and duration of cannabis' effects puts them at heightened risk for experiencing harms related to driving under the influence. Use of alcohol and cannabis peak at age 16, the legal age teens may apply for a provisional driver's license in some states. Targeting novice teen drivers prior to licensure is thus an ideal time for prevention efforts focused on reducing alcohol and/or cannabis initiation, use, and impaired driving.

METHODS

The current study proposes to evaluate the efficacy of webCHAT among 15.5 to 17-year-old adolescents (n = 150) recruited at driver education programs. WebCHAT is a single session online intervention that aims to prevent alcohol and cannabis use and risky driving behaviors. We will recruit adolescents enrolled in driver education programs, and stratify based on whether they used cannabis and/or alcohol in the past 3 months (60% screening negative and 40% screening positive). All participants will receive usual driver education and half will also receive webCHAT. We will test whether webCHAT in addition to usual driver education reduces alcohol and/or cannabis initiation or use and reduces risky driving attitudes and behaviors (intent to drive after drinking/using, riding as a passenger with someone who drank/used) compared to teens in usual driver education over a 6-month period. We will also explore whether variables such as beliefs and perceived norms serve as explanatory mechanisms for our outcomes.

DISCUSSION

The study has the potential to promote public welfare by decreasing adolescent initiation and use of cannabis and alcohol and reducing risky driving behaviors that can have substantial monetary, personal, and social costs. The study recruits adolescents who are at risk for substance use as well as those who are not and it is delivered remotely during a teachable moment when adolescents receive driver education. Trial registration This study was registered with ClinicalTrials.gov on July 13, 2021 (NCT04959461). https://clinicaltrials.gov/ct2/show/NCT04959461.

Effectiveness of D.A.R.E/Keepin' it REAL bullying prevention program among Brazilian students

INTRODUCTION

Given the growing scientific evidence on the detrimental effects of bullying, several prevention programs have been implemented internationally to prevent this behavior among students. Brazil's Educational Program for Drug and Violence Resistance (PROERD) is an adaptation of US' DARE/Keepin' it REAL program, being the most widespread school-based prevention program in the country. However, it has been offered without any effectiveness evaluation. As such, this study evaluates the effectiveness of PROERD in reducing bullying perpetration and victimization among students.

METHODS

Two cluster randomized controlled trials were carried out with 4030 students (1727 5th graders and 2303 7th graders) in 30 public schools in São Paulo, Brazil. The intervention group attended 10 PROERD classes taught by trained police officers whereas the control group underwent no intervention. Data were collected by self-administered questionnaires using smartphones at two moments (baseline preintervention and 9-month follow-up). Multilevel analysis included two paradigms, complete cases (CC) and intention-to-treat (ITT), using Full Information Maximum Likelihood (FIML) and Multiple Imputation (MI). RESULTS AND CONCLUSION: Results show no statistical difference between groups, indicating lack of evidence on PROERD's effectiveness in preventing bullying behaviors. The insufficient number of classes on bullying prevention and the lack of cultural adaptation may explain these unexpected results. New in-depth evaluation studies concerning the program's components and process are needed.

Effectiveness of a school-based substance use prevention program taught by police officers in Brazil: Two cluster randomized controlled trials of the PROERD

BACKGROUND

The Drug and Violence Resistance Educational Program (PROERD) is widely disseminated and implemented as a public policy in Brazil. PROERD's current curricula are the translation of the North American program DARE-Keepin'it REAL, based on the theories of socio-emotional learning and resistance training. The present study aims to evaluate the effectiveness of PROERD in the prevention of drug use.

METHOD

Two PROERD curricula were analyzed through two cluster randomized controlled trials conducted with 4030 students (1727 5th graders and 2303 7th graders) in 30 public schools in São Paulo. The intervention group received ten PROERD classes delivered by trained police officers, and the control group received no intervention. Data collection was performed using self-administered questionnaires on smartphones at two points in time (baseline pre-intervention and nine months follow-up). The outcomes evaluated were initiation and recent drug use. Two different paradigms were used in a multilevel analysis: an analysis of complete cases (CC) and an intention to treat missing data through full information maximum likelihood and selection model.

RESULTS

We found no evidence of the effectiveness of PROERD as an intervention for the prevention of drug use. For the conditional transition analysis, we found that 7th graders in the PROERD group who were already binge drinking at baseline had a significantly higher chance of maintaining this consumption pattern when compared to the control group.

CONCLUSION

The lack of preventive effects found here suggests that a process evaluation may address concrete implementation and cultural adaptation issues.

[Universal prevention of substance use in school settings: the need for continuous monitoring]

This paper documents the management of two programs for the universal prevention of substance use offered in secondary schools by the public health services of the city of Barcelona, reviewing the period from 1989-1990 to 2016-2017. Both programs had proven effectiveness in evaluations with a comparison group, they are promoted by the public health agency free of cost, and are taught by teachers, using standardized manuals with support materials and training. The coverage achieved over recent years declined from 40% to 25%. Changes observed in the acceptance and implementation of these programs could be related with logistics and follow-up by the public health services, changes in substance availability, and with budget cuts in education. The monitoring of effective programs by public health services is essential to preserve their actual implementation.

Effects of a School-Based Drug Prevention Program on Sexual Risk Behavior Among Adolescents in Brazilian Schools

Sexual risk behaviors are closely related to the use of alcohol, tobacco, and other illicit drugs as well as teen dating violence. School-based drug prevention programs that teach social and personal skills could potentially also reduce sexual risk behaviors. We examined the effects of the #Tamojunto program on youth sexual risk behaviors. A randomized controlled trial was conducted with 6391 7th and 8th grade students in 72 public schools in six Brazilian cities. Baseline data were collected prior to program implementation. Two waves of follow-up assessments occurred after 9 and 21 months. Analyses were performed taking into account the multilevel structure of the data. We used intention-to-treat to evaluate changes in the prevalence of sexual risk behaviors over time and between groups. Adolescent age ranged from 11 to 15 years, with a mean of 12.6 ± 0.8 years, and 51.0% were female. Among all participants, receipt of #Tamojunto was associated with higher risk of lifetime sex at 21 months follow-up (OR 1.27, 95% CI [1.03, 1.56]). Among girls, at 9 months follow-up, the program was associated with higher likelihood of having engaged in sex in the last month (OR 1.76, 95% CI [1.13, 2.74]). At 21 months follow-up, girls receiving the program were more likely to report engaging in condomless sex in the last month (OR 1.64, 95% CI [1.07, 2.50]). #Tamojunto may be ineffective and possibly harmful for preventing sexual risk behaviors, especially among girls. We suggest further investigation of the possible mediating role of life skills intervention components on girl's sexual behaviors.

Effectiveness of the Elos 2.0 prevention programme for the reduction of problem behaviours and promotion of social skills in schoolchildren: study protocol for a cluster-randomized controlled trial

BACKGROUND

Early interventions benefit the mental health, academic performance and productivity of children and adolescents throughout their life. The present study protocol will evaluate the effectiveness of the Elos 2.0 Programme, which is a version adapted for Brazil by the Ministry of Health, in reducing problem behaviours (e.g., disruptiveness, aggressivity and shyness) and promoting social skills in the school context in children 6 to 10 years of age. The Elos Programme is based on the Good Behaviour Game, which is widely used and prevents and/or reduces students' disruptive behaviours by establishing cooperation contingencies.

METHOD

A cluster-randomized controlled trial will be performed in 30 schools in three cities (15 controls and 15 in the experimental group), with a total of 3800 children participating in the test (1900 in the control group and 1900 in the intervention group). Data will be collected by having teachers in the control and experimental classes complete the Teacher Observation of Classroom Adaptation (TOCA) questionnaire, which is an instrument used to observe children's behaviour in the classroom. We will collect data before and after the intervention period in the same year. Due to the hierarchical structure of the data, multilevel analysis will be performed to detect simultaneous differences in prevalence over time and across groups to control for sociodemographic variables.

DISCUSSION

The current study will examine the effectiveness of the Elos 2.0 Programme in reducing problem behaviours (e.g., disruptiveness, aggressivity and shyness) and promoting social skills in the school context. The findings of this school-based prevention programme for children will influence the development and implementation of similar programmes for schools and educational policymakers by identifying mechanisms that are central to achieving positive outcomes for participants.

TRIAL REGISTRATION

Registry of Clinical Trials of the Ministry of Health RBR-86c6jp . Registered February 2, 2019.

A cluster randomized controlled trial evaluating the effectiveness of the school-based drug prevention program #Tamojunto2.0

AIMS

The study aimed to evaluate the effectiveness of the government school-based program #Tamojunto2.0, the third Brazilian version of the European drug prevention program, Unplugged, in preventing the use of alcohol and other drugs.

DESIGN

A parallel, two-arm cluster randomized controlled trial was conducted in 205 classes in 73 public schools (37 intervention and 36 control) with a baseline assessment and follow-up after 9 months.

SETTING

Schools in the cities of São Paulo, Fortaleza and Eusebio in Brazil.

PARTICIPANTS

A total of 5208 students in the 8th grade with a mean age of 13.2 years (standard deviation = 0.8 years) and an equal gender ratio.

INTERVENTION

In 2019, the intervention group attended 12 classes of the program #Tamojunto2.0, under the supervision of a team from the Ministry of Health. The control group did not receive any intervention to prevent alcohol and drug use.

MEASUREMENTS

The primary outcome measured was prevalence of binge drinking (five or more doses of alcohol in an occasion) within the past month. Secondary outcomes were prevalence of initiation and use of alcohol, tobacco, inhalants, marijuana and cocaine within the past month.

FINDINGS

A statistically significant difference was not found in the prevalence of binge drinking within the past month between intervention and control groups [odds ratio (OR) = 0.934; 95% confidence interval (CI) = 0.761-1.146]. However, students who were exposed to the program were less likely to initiate alcohol use than those in the control group (OR = 0.782; 95% CI = 0.636-0.961). The Bayes factor for reduction in binge drinking was 0.01, providing evidence in favor of the null hypothesis for this variable.

CONCLUSIONS

The drug prevention program #Tamojunto 2.0 reduced alcohol initiation, but appeared not to reduce past-month binge drinking among 8th grade students in Brazil.

Three-Year Follow-Up of the POIBA Intervention on Childhood Obesity: A Quasi-Experimental Study

Childhood obesity has increased worldwide over the past four decades. This quasi-experimental study aimed to assess the effectiveness of a multicomponent and multilevel school-based intervention (POIBA) at 3 years of follow-up. The nutrition intervention focused on food groups, food pyramid, nutrients, portions, and balanced menus. In total, 3624 children participated in the study. Anthropometric measurements and information on food frequency and behavior, physical activity, and daily screen use were collected in the intervention (IG) and comparison group (CG). Positive unadjusted changes toward adherence to recommendations were found for water, meat, sweets, and fried potato consumption, proper breakfast, not having dinner in front of the TV, out-of-school physical activity, and daily screen use. Three scores were used to calculate the proportion of children making more than one change to improve healthy habits regarding physical activity (global Activity score), nutrition (global Nutrition score), and both (global score). Students exposed to the intervention had a significantly better global Activity score (16.2% IG vs. 11.9% CG; p = 0.012) and Global score (63.9% IG vs. 58.5% CG; p = 0.025). Intervention effects on obesity incidence at 3-year follow-up lost significance but maintained the positive trend. In conclusion, school-based interventions including a family component could be useful to address the childhood obesity problem.

Evaluating the effects of parenting styles dimensions on adolescent drug use: secondary analysis of #Tamojunto randomized controlled trial

The present study examined parenting style dimensions (demandingness and responsiveness) as predictors of adolescent drug use and also evaluated whether parenting styles dimensions moderate the effects of the implemented prevention program. 6.391 students in the 7th and 8th grades at 72 Brazilian public schools participated in a three-wave randomized controlled trial to evaluate a school drug-use prevention program. We used structural equation modeling to test if baseline parenting style dimensions (demandingness and responsiveness) would predict the use of drugs (alcohol, binge drinking, cannabis, inhalants, and tobacco) after 21 months. Additionally, we evaluated an interaction version of the above-described model to test if the effect of the prevention program would be moderated by either or both parenting style dimensions. Higher levels of parent demandingness predicted lower chances of adolescent drug use (e.g., Cigarette use OR 0.76, 95% CI 0.64-0.89); responsiveness on the five outcomes showed p value superior to 0.01. The effect of the #Tamojunto intervention is unlikely to be conditioned to either parenting style dimensions on the assessed outcomes.Clinical trial registration Brazilian Register of Clinical Trials (REBEC): #RBR-4mnv5g ( https://www.ensaiosclinicos.gov.br/rg/?q=tamojunto ).

Transition from nonuse to use of alcohol or binge drinking among adolescents: Secondary analysis of a randomized controlled trial

OBJECTIVE

The objective of this study was to evaluate the predictors of the transition from nonuse of alcohol to the first use of alcohol and the first episode of binge drinking.

METHODS

Data were drawn from a randomized controlled trial conducted with seventh- and eighth-grade students from 72 public schools over a 21-month period in six cities in Brazil. A total of 3298 students who reported that they had never consumed alcoholic beverages and had never engaged in binge drinking at baseline were included in this study. The two binary outcomes were tested concomitantly via structural equation modeling. Maximum likelihood estimates for logistic regression models were performed to evaluate how baseline data regarding risk factors, such as sociodemographic characteristics (socioeconomic status, gender, and age), school experiences (violence and perception of academic performance), and social variables (family and friends), affected the initiation of alcohol use and binge drinking at 9- and 21-month follow-up assessments.

RESULTS

Older age, the perpetration of violent behaviors at baseline and the absence of the father living with the adolescent were predictors of both alcohol use initiation and binge drinking initiation. The #Tamojunto program showed iatrogenic effect for first alcohol use.

CONCLUSIONS

The results indicate the need to develop and implement effective alcohol prevention programs that consider the main characteristics in the prediction model for alcohol consumption and binge drinking, including early intervention for aggressive behaviors at school and parental alcohol use.

Decision-making skills as a mediator of the #Tamojunto school-based prevention program: Indirect effects for drug use and school violence of a cluster-randomized trial

BACKGROUND

The aim of the present study was to evaluate a formal mediation analysis effect of the #Tamojunto program on adolescents' drug use and violent behavior in schools through decision-making skills using a potential outcomes approach.

METHODS

An in-cluster randomized controlled trial was conducted in 2014-2015 with 6691 7th- and 8th-grade students in 72 public schools in 6 Brazilian cities to evaluate the effects of the European drug prevention program Unplugged, called #Tamojunto in Brazil. Baseline data were collected prior to program implementation, and follow-up data were collected 9 and 21 months later. Mediation analysis using a potential outcomes approach, in which counterfactuals are modeled if positivity is met, was used to evaluate the indirect effects of the program #Tamojunto on the third-wave of drug use (alcohol, tobacco, marijuana, inhalants, and binge drinking) and school violence (bullying or physical, verbal and sexual aggression) assessment through decision-making skills.

RESULTS

When controlling for all covariates, the Total Natural Indirect Effect (TNIE) was significant only for past-year drug use (TNIE = 0.003, 95%CI = 0.001; 0.007). In the adjusted models, 37.5% of the effect of the intervention on drug use was mediated by decision-making skills.

CONCLUSIONS

The #Tamojunto program increased drug use through decreasing decision-making skills. The findings demonstrate that this program changes decision-making skills but in the opposite direction proposed by the theoretical model of the program, suggesting that modifications are needed to produce the intended effect of the program.

Does liberalisation of cannabis policy influence levels of use in adolescents and young adults? A systematic review and meta-analysis

OBJECTIVES

To examine the effect of cannabis policy liberalisation (decriminalisation and legalisation) levels of use in adolescents and young adults.

DESIGN

Systematic review and meta-analysis.

INCLUSION CRITERIA

Included studies were conducted among individuals younger than 25 years and quantitatively assessing consequences of cannabis policy change. We excluded articles: (A) exclusively based on participants older than 25 years; (B) only reporting changes in perceptions of cannabis use; (C) not including at least two measures of cannabis use; (D) not including quantitative data; and (E) reviews, letters, opinions and policy papers. PubMed, PsycINFO, Embase and Web of Science were searched through 1 March 2018.

DATA EXTRACTION AND SYNTHESIS

Two independent readers reviewed the eligibility of titles and abstracts and read eligible articles, and four authors assessed the risk of bias (Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies). Extracted data were meta-analysed. The protocol was registered with PROSPERO.

RESULTS

3438 records were identified via search terms and four via citation lists; 2312 were retained after removal of duplicates, 99 were assessed for eligibility and 41 were included in our systematic review. 13 articles examined cannabis decriminalisation, 20 examined legalisation for medical purposes and 8 examined legalisation for recreational purposes. Findings regarding the consequences of cannabis decriminalisation or legalisation for medical purposes were too heterogeneous to be meta-analysed. Our systematic review and meta-analysis suggest a small increase in cannabis use among adolescents and young adults following legalisation of cannabis for recreational purposes (standardised mean difference of 0.03, 95% CI -0.01 to -0.07). Nevertheless, studies characterised by a very low/low risk of bias showed no evidence of changes in cannabis use following policy modifications.

CONCLUSIONS

Cannabis policy liberalisation does not appear to result in significant changes in youths' use, with the possible exception of legalisation for recreational purposes that requires monitoring.

TRIAL REGISTRATION NUMBER

CRD42018083950.

Effectiveness evaluation of the school-based drug prevention program #Tamojunto2.0: protocol of a cluster randomized controlled trial

Background

The European school-based drug addiction prevention program Unplugged was adapted to the Brazilian context by the Ministry of Health and renamed #Tamojunto. Its first implementations, in the form of a public policy in Brazil, showed contradictory and different effects from those observed in Europe. Adaptations were made to #Tamojunto in 2018 to reintroduce the essential content of the original program.

Methods

A parallel, two-arm, randomized controlled trial (RCT) will be conducted to evaluate the effectiveness of the new version of the school-based government program #Tamojunto2.0 for the prevention of drug use among 8th grade middle school students from 70 public schools in three Brazilian cities, totaling approximately 6.300 participating students distributed in 210 classes. For intervention, the experimental group will receive the 12 lessons of the #Tamojunto2.0 program under the supervision of a Brazilian Ministry of Health team. The control group will not receive any intervention. Information will be collected from the students at three time points: preintervention and 9 and 18 months postintervention. Multilevel analyses will be performed using the Gllamm Stata program to assess simultaneous differences in prevalence, in time and among groups for the outcomes of interest. Structural equation modeling will be used to evaluate the effectiveness of the intervention in changing the behavioral patterns of the adolescents through latent transition analysis. The effect of the mediators involved in the program effectiveness outcomes will also be analyzed. The program doses applied in all classes of the intervention group will be collected using a form completed by the teacher at the end of each lesson, indicating the activities taught and not taught in each lesson.

Discussion

This study will show whether the #Tamojunto2.0 program can be expanded as a public policy for all schools with the aim of preventing drug use among Brazilian students.

Trial registration

Brazilian Clinical Trials Registry (RBR-8cnkwq) under the name “Avaliação do Efeito do Programa de Prevenção Escolar ao Uso de Drogas #Tamojunto2.0, Versão 2018”, on August 30th, 2018 (http://www.ensaiosclinicos.gov.br/rg/RBR-8cnkwq/).

Predicting latent classes of drug use among adolescents through parental alcohol use and parental style: a longitudinal study

PURPOSE

The present study examined the roles of parental alcohol use and parental style as predictors of adolescent patterns of drug use.

METHODS

6391 students in the 7th and 8th grades at 72 Brazilian public schools participated in a three-wave randomized controlled trial to evaluate a school drug-use prevention program. Patterns of drug use were identified through two latent class analyses using measures of the adolescents' past-year drug use. Multinomial logistic regression analyses examined whether parental alcohol use and parenting style at baseline predicted patterns of drug use in waves 2 and 3 of the study after controlling for sociodemographic covariates.

RESULTS

In each of the two waves, three latent classes of drug use were identified among the students, defining three different groups of individuals: (1) abstainers/low users, (2) alcohol users/binge drinkers, and (3) polydrug users. First, parenting style (especially monitoring) was the strongest predictor for the prevention of polydrug use among adolescents. Second, occasional alcohol use by parents can act as a central predictor for adolescent alcohol use and binge drinking. Above all, maternal episodes of drunkenness were involved in the predictive models for both drug use classes in both waves.

CONCLUSION

Parental alcohol use and parenting style seem to be important predictors of adolescent's likelihood of belonging to different latent classes of drug use. This conclusion may point to the importance of considering the inclusion of parenting skills and parental alcohol use within the scope of adolescents' preventive interventions.

Effectiveness evaluation of the school-based drug prevention program #Tamojunto in Brazil: 21-month follow-up of a randomized controlled trial

INTRODUCTION

A school-based randomized controlled trial was conducted in 2014/2015 with students in 7^th and 8^th grades in 72 public schools in 6 Brazilian cities. A total of 5028 students were linked (75, 7%) in at least one of the two waves of follow-up (9 months and 21 months later). The principal research question was whether this 12-lesson program delays the initiation of alcohol, tobacco, inhalants and binge drinking among early adolescents when compared to usual care, that is, no prevention program in Brazilian schools, after 21 months of follow up.

METHODS

Cox regression models were adjusted to evaluate the incidence of drug use. Generalized linear latent mixed models (GLLAMM) were used to evaluate changes in the prevalence of each drug over time and between groups. Findings The incidence analysis showed a negative effect of the program for alcohol initiation (aHR = 1.13, 95%CI 1.01; 127) but an opposite protective effect for the initiation of inhalant use (aHR = 0.79, 95%CI 0.66; 0.95). After 21 months, the prevalence of past-year use of alcohol changed from 30.1% to 49.8% in the intervention group and from 29.9% to 45.8% in the control group. Adolescents in the intervention group were 30% more likely to have reported past-year use of alcohol than students in the control group at 21 months (aOR = 1.30, 95%CI 1.02; 1.65). No effects of the program on past-month drug use were found. The Brazilian version of the Unplugged program may be misinterpreted by public school students, perhaps arousing their curiosity regarding alcohol use.

Cost-Effectiveness of School-Based Prevention of Cannabis Use

BACKGROUND

Cannabis is the most frequently used illicit drug globally. Despite increasing evidence that cannabis use is associated with adverse health effects, the knowledge on preventative strategies is still limited. This study stemmed from a systematic review of effective prevention in which school-based programmes were identified as promising. The primary objective was to evaluate the cost effectiveness of Project ALERT (Adolescent, Learning, Experiences, Resistance, and Training), compared with ordinary ATOD (Alcohol, Tobacco, and Other Drug) education, among Swedish students in the eighth grade of compulsory school.

METHODS

The cost-effectiveness analysis was performed from the societal perspective with quality-adjusted life-years (QALYs) as an outcome (willingness-to-pay threshold €50,000) and follow-up periods from 1 year to a lifetime, considering a discounting rate of 3%, and with costs inflated to 2013 levels. A Markov model was constructed on the basis of the 'states' of single use, regular use, daily use and use of other illicit drugs, which were associated with 'complications' of psychosis, schizophrenia, traffic accidents, depression and amotivational syndrome. Health and cost consequences were linked to both states and complications.

RESULTS

The programme was cost saving on the basis of evidence from the USA (ratio 1:1.1), and was cost effective (incremental cost-effectiveness ratio €22,384 per QALY) after reasonable adjustment for the Swedish context and with 20 years of follow-up. When the target group was restricted to boys who were neither studying nor working/doing work experience, the programme was cost effective after 9 years and cost saving (ratio 1:3.2) after 20 years.

CONCLUSION

School-based prevention such as Project ALERT has the potential to be cost effective and to be cost saving if implemented in deprived areas. In the light of the shifting landscape regarding legalization of cannabis, it seems rational to continue the health economic analysis of prevention initiated here.