The creation of evidence in ‘evidence-based’ drug prevention: a critique of the Strengthening Families Program Plus Life Skills Training evaluation

Homegrown: Parent and Sibling Substance Abuse Linked to Opioid Misuse Among Justice-Involved Children

Opioid misuse (OM) is a priority public health concern, especially for those in correctional settings. Understanding the etiology of OM among justice-involved children (JIC) is key to resolving this crisis. On average, 12% of all children and up to 50% of JIC in the United States have experienced household substance misuse (HSM). Theory and empirical research suggest that HSM may increase risk for OM, but these relationships have not been examined among JIC. The objective of this study was to examine the effects of sibling and parent substance misuse on OM among JIC. Cross-sectional data on 79,960 JIC from the Florida Department of Juvenile Justice (FLDJJ) were examined. Past 30-day opioid (P30D) OM was indicated by urine analysis. Bivariate and multivariate logistic regression analyses were employed. In the total sample, nearly 3% met FLDJJ criteria for P30D OM and nearly 25% lived with a parent/caregiver or sibling who misused substances. Among opioid misusers, one third lived with a parent/caregiver who misused substances and nearly half lived with a parent/caregiver or sibling who misused substances. Compared to JIC without HSM, JIC reporting sibling substance misuse had 1.95 times higher odds of OM (95% CI, 1.63-2.33), JIC with parent substance misuse had over twice the odds of OM (95% CI, 1.89-2.31), and those with both sibling and parent had more than three times higher odds of OM (95% CI, 2.75-3.87). Family-based approaches to OM intervention and prevention initiatives may be more effective than individual-focused approaches. Implications are discussed.

Evaluating a school-based science program that teaches the physiological effects of nicotine

School-based drug prevention programs represent a widely endorsed public health goal, with an important aspect of knowledge-based curricula being education about the physiological effects of drugs. Nicotine is one of the world's most addictive substances and in this program we have used nicotine-induced mammalian-like behaviors in flatworms called planarians to successfully teach students (4th-12th grade; n = 1,616 students) about the physiological and addictive effects of nicotine. An initial study tested the change in knowledge about addictive substances in 6th-12th grade students after they completed a lab examining the effects of two concentrations of nicotine on the number of stereotypies (C-shaped spasms) planarians demonstrate in a 5-minute period of time. Lab discussion focused on developing and testing hypotheses, measurement reliability, and mechanisms of nicotine action. Surveys given pre- and post-lab experience showed that 6th grade students have significantly lower knowledge about nicotine than 7th-12th grade students (6th grade: 40.65 ± 0.78% correct, 7th-12th grade: 59.29 ± 1.71%, p < 0.001) pre-lab, but that students in all grades showed a significant increase in knowledge post-lab (p < 0.001). In 6th grade the lab was effective in improving knowledge about nicotine in urban, suburban and rural schools, p < 0.001, with students in suburban schools showing significantly greater knowledge both pre-test (urban: 37.62 ± 1.45%; suburban: 48.78 ± 1.62%; rural: 37.33 ± 0.99%; p < 0.001) and post-test (urban:60.60 ± 1.85%; suburban: 67.54 ± 1.82%; urban: 61.66 ± 1.18%; p < 0.001). A second study, modifying the lab so that the time spent observing the planarians is reduced to a 1-minute period, showed that students in both 4th and 5th grades had a significant increase in knowledge about the physiological and addictive effects of nicotine post-lab (p < 0.001).

Políticas de prevenção ao abuso de drogas no Brasil e nos Estados Unidos

O objetivo deste estudo foi discutir as políticas públicas de prevenção ao abuso de drogas destinadas aos jovens no Brasil e nos Estados Unidos. A formulação dessa política no Brasil tem-se estabelecido a partir de programas que são questionados internacionalmente em termos epistemológicos, teóricos e metodológicos. Conclui-se que a construção de políticas sociais na América Latina permanece atravessada pela manutenção da dependência aos países centrais, uma vez que as tensões entre os modelos proibicionista e de redução de danos se mantêm entre o que preveem as políticas de prevenção ao abuso de drogas da Secretaria Nacional de Políticas sobre Drogas e do Ministério da Saúde e o que de fato é executado. Sugere-se buscar autonomia em relação aos modelos de ações preventivas impostos pelos países dominantes, por meio de um debate mais amplo entre pesquisadores, profissionais, usuários e movimentos sociais para o protagonismo de políticas mais adequadas ao Brasil.

Challenges Facing Evidence-Based Prevention: Incorporating an Abductive Theory of Method

Current systems used to determine whether prevention programs are "evidence-based" rely on the logic of deductive reasoning. This reliance has fostered implementation of strategies with explicitly stated evaluation criteria used to gauge program validity and suitability for dissemination. Frequently, investigators resort to the randomized controlled trial (RCT) combined with null hypothesis significance testing (NHST) as a means to rule out competing hypotheses and determine whether an intervention works. The RCT design has achieved success across numerous disciplines but is not without limitations. We outline several issues that question allegiance to the RCT, NHST, and the hypothetico-deductive method of scientific inquiry. We also discuss three challenges to the status of program evaluation including reproducibility, generalizability, and credibility of findings. As an alternative, we posit that extending current program evaluation criteria with principles drawn from an abductive theory of method (ATOM) can strengthen our ability to address these challenges and advance studies of drug prevention. Abductive reasoning involves working from observed phenomena to the generation of alternative explanations for the phenomena and comparing the alternatives to select the best possible explanation. We conclude that an ATOM can help increase the influence and impact of evidence-based prevention for population benefit.

School-based programmes that seem to work

H. Pape: School-based programmes that seem to work: Useful research on substance use prevention or suspicious stories of success?

School-based prevention programmes targeted at adolescent substance use rarely seem to have the desired effects on behaviour. It is true that some outcome studies do conclude that such programmes have been successful, but they are relatively few and far between. Even so, one may ask whether the body of published research in this field may originate from unrealistic optimism due to publication bias and underreporting of no or counterproductive effects. Thus, anecdotal evidence suggests that the literature is biased in favour of studies with positive findings. Moreover, nearly all these studies have been carried out by programme developers, and it is well known that researchers with vested interests are more likely to bring “good news” than independent researchers. Indeed, rather than approaching the field with critical reflection, some evaluators have intended to prove that school-based prevention works and have conducted their research accordingly. Examples of questionable analytical approaches and selective reporting of positive ifindings are consequently not hard to find. The external validity of evaluation studies with favourable outcomes is also often questionable because they almost exclusively have assessed the effects of programmes delivered under optimal rather than real-life conditions. In conclusion, the empirical “evidence” in favour of school-based substance use prevention programmes is generally weak and does not allow recommendation of widespread dissemination of any specific programme.

A systematic review of combined student- and parent-based programs to prevent alcohol and other drug use among adolescents

ISSUES

Alcohol and other drug use among adolescents is a serious concern, and effective prevention is critical. Research indicates that expanding school-based prevention programs to include parenting components could increase prevention outcomes. This paper aims to identify and describe existing combined student- and parent-based programs for the prevention of alcohol and other drug use to evaluate the efficacy of existing programs.

APPROACH

The PsycINFO, Medline, Central Register of Controlled trials and Cochrane databases were searched in April 2015 and additional articles were obtained from reference lists. Studies were included if they evaluated a combined universal intervention for students (aged 11-18 years old) and their parents designed to prevent alcohol and/or other drug use, and were delivered in a school-based setting. Risk of bias was assessed by two independent reviewers. Because of the heterogeneity of the included studies, it was not possible to conduct a meta-analysis and a qualitative description of the studies was provided.

KEY FINDINGS

From a total of 1654 screened papers, 22 research papers met inclusion criteria, which included 13 trials of 10 programs. Of these, nine programs demonstrated significant intervention effects in terms of delaying or reducing adolescent alcohol and/or other drug use in at least one trial.

CONCLUSION

This is the first review of combined student- and parent-based interventions to prevent and reduce alcohol and other drug use. Whilst existing combined student- and parent-based programs have shown promising results, key gaps in the literature have been identified and are discussed in the context of the development of future prevention programs. [Newton NC, Champion KE, Slade T, Chapman C, Stapinski L, Koning I, Tonks Z, Teesson M. A systematic review of combined student- and parent-based programs to prevent alcohol and other drug use among adolescents. Drug Alcohol Rev 2017;36:337-351].

Independent Evaluation of Middle School-Based Drug Prevention Curricula: A Systematic Review

IMPORTANCE

Lack of robust program evaluation has hindered the effectiveness of school-based drug abuse prevention curricula overall. Independently evaluated randomized controlled trials (RCTs) of universal, middle school-based drug abuse prevention curricula are the most useful indicators of whether such programs are effective or ineffective.

OBJECTIVE

To conduct a systematic review identifying independently evaluated RCTs of universal, middle school-based drug abuse prevention curricula; extract data on study quality and substance use outcomes; and assess evidence of program effectiveness.

EVIDENCE REVIEW

PsycInfo, Educational Resources Information Center, Science Citation Index, Social Science Citation Index, Cumulative Index to Nursing and Allied Health Literature, MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews were searched between January 1, 1984, and March 15, 2015. Search terms included variations of drug, alcohol, tobacco, and marijuana use, as well as school, prevention, and effectiveness. Studies included in the review were RCTs carried out by independent evaluators of universal school-based drug prevention curricula available for dissemination in the United States that reported alcohol, tobacco, marijuana, or other drug use outcomes. Two researchers extracted data on study quality and outcomes independently using a data extraction form and met to resolve disagreements.

FINDINGS

A total of 5071 publications were reviewed, with 13 articles meeting final inclusion criteria. Of the 13 articles, 6 RCTs of 4 distinct school-based curricula were identified for inclusion. Outcomes were reported for 42 single-drug measures in the independent RCTs, with just 3 presenting statistically significant (P < .05) differences between the intervention group and the control group. One program revealed statistically significant positive effects at final follow-up (Lions-Quest Skills for Adolescence).

CONCLUSIONS AND RELEVANCE

The results of our review demonstrate the dearth of independent research that appropriately evaluates the effectiveness of universal, middle school-based drug prevention curricula. Independent evaluations show little evidence of effectiveness for widely used programs. New methods may be necessary to approach school-based adolescent drug prevention.

Implementing and evaluating the German adaptation of the "Strengthening Families Program 10 - 14"- a randomized-controlled multicentre study

BACKGROUND

Substance use problems in childhood and adolescence can severely impact youth's physical and mental well-being. When substance use is initiated early, the risk for moving from hazardous substance use to substance use disorders (SUD) is particularly high to developmentally induced biological and psychological vulnerability towards chronic trajectories in youth. Thus, risk factors for developing SUD should be addressed early in life by adequate preventive measures reaching out to children, adolescents, and their families. The study described in this protocol will test the effectiveness of the German adaptation of the Strengthening Families Program for Parents and Youth 10-14 (SFP 10-14) aimed at ten to 14 year old adolescents and their caregivers.

METHODS/DESIGN

The study is conducted in four large German cities by counselling centres in the areas of youth welfare, social work and addiction aid. The effectiveness of the manualised group programme "Familien Stärken" consisting of seven sessions and four booster-sessions is tested among N = 288 children and participating parents in a multicentre randomised controlled trial with standardised assessment instruments. The control condition receives a minimal 2-hour intervention on parenting delivered in a school setting. Data are collected shortly before and after as well as six and 18 months after the intervention. We expect to replicate the favourable effects of the SFP 10-14 programme in the United States in the area of substance use initiation, family functioning and individual psychosocial adjustment.

DISCUSSION

The trial is expected to contribute to the growing literature on family-based preventive interventions, their effectiveness and feasibility. It is in line with several other current European efforts aimed at strengthening families against the detrimental effects of substance abuse in youth. The results of these trials will expand our knowledge on adapting evidence-based interventions and delivering them in diverse cultures and settings.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN90251787.

Preventing substance misuse: study protocol for a randomised controlled trial of the Strengthening Families Programme 10-14 UK (SFP 10-14 UK)

BACKGROUND

Prevention of alcohol, drug and tobacco misuse by young people is a key public health priority. There is a need to develop the evidence base through rigorous evaluations of innovative approaches to substance misuse prevention. The Strengthening Families Programme 10-14 is a universal family-based alcohol, drugs and tobacco prevention programme, which has achieved promising results in US trials, and which now requires cross-cultural assessment. This paper therefore describes the protocol for a randomised controlled trial of the UK version of the Strengthening Families Programme 10-14 (SFP 10-14 UK).

METHODS/DESIGN

The trial comprises a pragmatic cluster randomised controlled effectiveness trial with families as the unit of randomisation, with embedded process and economic evaluations. Participating families will be randomised to one of two treatment groups - usual care with full access to existing services (control group), or usual care plus SFP 10-14 UK (intervention group). The trial has two primary outcomes - the number of occasions that young people report having drunk alcohol in the last 30 days, and drunkenness during the last 30 days, both dichotomised as 'never' and '1-2 times or more'. The main follow-up is at 2 years past baseline, and short-term and intermediate outcomes are also measured at 9 and 15 months.

DISCUSSION

The results from this trial will provide evidence on the effectiveness and cost-effectiveness of an innovative universal family-based substance misuse prevention programme in a UK context.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN63550893.

Evaluation of the effectiveness of a smoking prevention program based on the 'Life Skills Training' approach

Our objective was to verify the effectiveness of a program based on the Life Skills Training approach with a greater extent than usual, not applied by teachers and a very high degree of reliability regarding the implementation of the expected content. Twenty-eight secondary schools in Granada (Spain) were randomly assigned to the intervention or control group. The students in the intervention group received 21 one-hour sessions in the first year and 12 one-hour sessions in the second year, whereas those in the control group received no health education or preventive sessions. Students completed questionnaires before and after the first year of sessions, before and after the second year, and at 1 year after the program. All five questionnaires were completed by 77% of the 1048 students initially enrolled in the study. The results suggest that the program had no preventive effects either immediately or at 1 year after its application. Application of the Life Skills Training approach does not appear to prevent the onset of smoking but may prove effective for avoiding escalation of the consumption levels of tobacco or other problematic drugs.

A cluster randomised trial of a school-based resilience intervention to decrease tobacco, alcohol and illicit drug use in secondary school students: study protocol

Background

Whilst schools provide a potentially appropriate setting for preventing substance use among young people, systematic review evidence suggests that past interventions in this setting have demonstrated limited effectiveness in preventing tobacco, alcohol and other drug use. Interventions that adopt a mental wellbeing approach to prevent substance use offer considerable promise and resilience theory provides one method to impact on adolescent mental well-being. The aim of the proposed study is to examine the efficacy of a resilience intervention in decreasing the tobacco, alcohol and illicit drug use of adolescents.

Methods

A cluster randomised controlled trial with schools as the unit of randomisation will be undertaken. Thirty two schools in disadvantaged areas will be allocated to either an intervention or a control group. A comprehensive resilience intervention will be implemented, inclusive of explicit program adoption strategies. Baseline surveys will be conducted with students in Grade 7 in both groups and again three years later when the student cohort is in Grade 10. The primary outcome measures will include self-reported tobacco, alcohol, marijuana and other illicit drug use. Comparisons will be made post-test between Grade 10 students in intervention and control schools to determine intervention effectiveness across all measures.

Discussion

To the authors’ knowledge this is the first randomised controlled trial to evaluate the effectiveness of a comprehensive school-based resilience intervention, inclusive of explicit adoption strategies, in decreasing tobacco, alcohol and illicit drug use of adolescents attending disadvantaged secondary schools.

Trial registration

ACTRN12611000606987

Assessment of generalizability, applicability and predictability (GAP) for evaluating external validity in studies of universal family-based prevention of alcohol misuse in young people: systematic methodological review of randomized controlled trials

AIMS

To assess external validity characteristics of studies from two Cochrane Systematic Reviews of the effectiveness of universal family-based prevention of alcohol misuse in young people.

METHODS

Two reviewers used an a priori developed external validity rating form and independently assessed three external validity dimensions of generalizability, applicability and predictability (GAP) in randomized controlled trials.

RESULTS

The majority (69%) of the included 29 studies were rated 'unclear' on the reporting of sufficient information for judging generalizability from sample to study population. Ten studies (35%) were rated 'unclear' on the reporting of sufficient information for judging applicability to other populations and settings. No study provided an assessment of the validity of the trial end-point measures for subsequent mortality, morbidity, quality of life or other economic or social outcomes. Similarly, no study reported on the validity of surrogate measures using established criteria for assessing surrogate end-points.

CONCLUSIONS

Studies evaluating the benefits of family-based prevention of alcohol misuse in young people are generally inadequate at reporting information relevant to generalizability of the findings or implications for health or social outcomes. Researchers, study authors, peer reviewers, journal editors and scientific societies should take steps to improve the reporting of information relevant to external validity in prevention trials.

The use of one- versus two-tailed tests to evaluate prevention programs

Investigators have used both one- and two-tailed tests to determine the significance of findings yielded by program evaluations. While the literature that addresses the appropriate use of each type of significance test should be used is historically inconsistent, almost all authorities now agree that one-tailed tests are rarely (if ever) appropriate. A review of 85 published evaluations of school-based drug prevention curricula specified on the National Registry of Effective Programs and Practices revealed that 20% employed one-tailed tests and, within this subgroup, an additional 4% also employed two-tailed tests. The majority of publications either did not specify the type of statistical test employed or used some other criterion such as effect sizes or confidence intervals. Evaluators reported that they used one-tailed tests either because they stipulated the direction of expected findings in advance, or because prior evaluations of similar programs had yielded no negative results. The authors conclude that one-tailed tests should never be used because they introduce greater potential for Type I errors and create an uneven playing field when outcomes are compared across programs. The authors also conclude that the traditional threshold of significance that places α at .05 is arbitrary and obsolete, and that evaluators should consistently report the exact p values they find.

Drug prevention programmes for young people: where have we been and where should we be going?

AIM

Substance use by young people has long been a concern of western society, but opinion is mixed as to which prevention approach offers the greatest benefit, and whether indeed there is any benefit at all. This paper reviews the nature of prevention programmes, the research evidence that underpins these programmes and the prevention objectives against which effectiveness is measured. The aim of this is to create better understanding of the elements that maximize programme effectiveness, what can be achieved by prevention programmes and how programmes can be improved.

FINDINGS

There is a range of prevention approaches for which there is evidence of effectiveness. Some are classroom-based; some focus upon parenting; some have substantial whole-of-school and community elements; and some target risk and protective factors in early childhood. All, however, are based substantially on the social influence model. In an attempt to improve practice lists of effective programmes have been developed, but there are concerns about the science behind selection. On balance, there is consistent evidence that social influence prevention programmes do have a small, positive effect on drug use, but this then raises the question as to whether harm, rather than use, would be the more worthwhile target for prevention. Prevention that seeks to reduce harm has been demonstrably effective, but has found little support in some jurisdictions.

CONCLUSION

Research has created a progressively better understanding of how to optimize programme effectiveness and what can be achieved realistically by even the most effective programmes. However, further research is required to identify which, if any, particular approach offers greater promise. The effectiveness of harm reduction should be compared with more traditional abstinence and the additional effects of whole of school, parent and community elements need to be measured more accurately. Contemporary social influence prevention programmes are flawed, but the approach is still the best way of influencing drug use behaviour in young people as a whole. Evidence-based refinement is the best option for greater benefit.

Project ALERT’s Effects on Adolescents’ Prodrug Beliefs: A Replication and Extension Study

This article represents a replication and extension of previous studies of the effects of Project ALERT, a school-based substance use prevention program, on the prodrug beliefs of adolescents. Specifically, the authors’ research examined Project ALERT’s effects on adolescents’ intentions to use substances in the future, beliefs about substance use consequences, normative beliefs, and resistance self-efficacy. In all, 34 schools with Grades 6 to 8 completed this randomized controlled trial and 71 Project ALERT instructors taught 11 core lessons to 6th graders and 3 booster lessons to 7th graders (one grade level earlier than in previous studies). Students were assessed in 6th grade prior to the onset of the intervention, in 7th grade after the completion of the 2-year curriculum, and again 1 year later in 8th grade. The authors found no evidence to suggest that Project ALERT had a positive impact on any alcohol, cigarette, or marijuana prodrug beliefs. Implications for school-based substance use prevention are discussed.

Prevention programs in the 21st century: what we do not discuss in public

Prevention research concerning alcohol, tobacco and other drugs faces a number of challenges as the scientific foundation is strengthened for the future. Seven issues which the prevention research field should address are discussed: lack of transparency in analyses of prevention program outcomes, lack of disclosure of copyright and potential for profit/income during publication, post-hoc outcome variable selection and reporting only outcomes which show positive and statistical significance at any follow-up point, tendency to evaluate statistical significance only rather than practical significance as well, problem of selection bias in terms of selecting subjects and limited generalizability, the need for confirmation of outcomes in which only self-report data are used and selection of appropriate statistical distributions in conducting significance testing. In order to establish a solid scientific base for alcohol, tobacco and drug prevention, this paper calls for discussions, disclosures and debates about the above issues (and others) as essential. In summary, the best approach is always transparency.

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.

Familienbasierte Prävention bei Kindern und Jugendlichen

Fragestellung: Wie evidenzbasiert sind familienbasierte Programme zur selektiven Suchtprävention? Lässt sich ein vorbildhaftes Programm identifizieren? Methodik: Überblick über entsprechende Ansätze und Programm-Merkmale als Ergebnis einer systematischen Literaturrecherche in verschiedenen Datenbanken. Ergebnisse: Das Strengthening Families Program 10–14 aus Iowa/USA (SFP 10–14) ist das wohl zurzeit best evaluierte familienbasierte universelle Präventionsprogramm; so ließen sich nachhaltige Effekte auch im 6-Jahres-Follow-up nachweisen. Schlussfolgerungen: Die kultursensitive Adaptation und Evaluation von SFP 10–14 für die Bundesrepublik kann die Prävention von Suchtstörungen wirkungsvoll ergänzen. Eine Adaptation für den deutschen Sprachraum hat verschiedene kultursensitive Aspekte zu berücksichtigen sowie den Umstand, dass SFP 10–14 aufwändig durchzuführen ist.

The Making of Evidence-based Practice: The Case of Project ALERT

Evidence-based practice has been enthusiastically embraced within the field of drug prevention during the past decade. Project ALERT, a school-based universal prevention program, is among the most widely advocated evidence-based interventions. We examined the results of three large-scale evaluations of Project ALERT, and concluded that assessment of data from the total samples shows that the program has little effect on drug use. Despite this, Project ALERT is included on evidence-based drug prevention lists because the criteria for inclusion are extremely weak. We discuss the implications of this for drug prevention evaluation research and the creation of evidence-based practice lists.

Artikel

H. Pape: School-based interventions that seem to work: Useful research on substance use prevention or suspicious stories of success?

School-based prevention programmes targeted at adolescent substance use rarely seem to have the desired effects on behaviour. It is true that some outcome studies do conclude that such programmes have been successful, but they are relatively few and far between. Even so, one may ask whether the body of published research in this field may originate from unrealistic optimism due to publication bias and underreporting of no or counterproductive effects. Thus, anecdotal evidence suggests that the literature is biased in favour of studies with positive findings. Moreover, nearly all these studies have been carried out by programme developers, and it is well known that researchers with vested interests are more likely to bring “good news” than independent researchers. Indeed, rather than approaching the field with critical refelction, some evaluators have intended to prove that school-based prevention works and have conducted their research accordingly. Examples of questionable analytical approaches and selective reporting of positive findings are consequently not hard to find. The external validity of evaluation studies with favourable outcomes is also often questionable because they almost exclusively have assessed the effects of programmes delivered under optimal rather than real-life conditions. In conclusion, the empirical “evidence” in favour of school-based substance use prevention programmes is generally weak and does not allow recommendation of widespread dissemination of any specific programme.

The social construction of "evidence-based'' drug prevention programs: a reanalysis of data from the Drug Abuse Resistance Education (DARE) program

This study explores the possibility that any drug prevention program might be considered ;;evidence-based'' given the use of data analysis procedures that optimize the chance of producing statistically significant results by reanalyzing data from a Drug Abuse Resistance Education (DARE) program evaluation. The analysis produced a number of statistically significant differences between the DARE and control conditions on alcohol and marijuana use measures. Many of these differences occurred at cutoff points on the assessment scales for which post hoc meaningful labels were created. Our results are compared to those from evaluations of programs that appear on evidence-based drug prevention lists.