Accuracy and Potential Benefit of Ultraselective Invasive Coronary Angiography Guided by Computed Tomographic Coronary Angiography.

OBJECTIVES: It is unknown whether computed tomographic coronary angiography (CTCA) can be used to perform ultraselective invasive coronary angiography (ICA) by only visualizing the abnormal coronary artery on CTCA and defer visualization of the normal contralateral coronary artery. This study assessed the accuracy of CTCA in patients with coronary artery disease (CAD) on CTCA limited to either the left (LCA) or right coronary artery (RCA) in predicting a contralateral coronary artery without abnormalities on CTCA determined to be normal by ICA. METHODS: This retrospective analysis included patients with CAD limited to the LCA or RCA on CTCA. Primary endpoint was the accuracy of CTCA to predict a contralateral coronary artery without abnormalities on CTCA to be normal by ICA. Secondary endpoints were potential reductions in procedure time and radiation exposure if an ultraselective ICA approach would be used compared to standard ICA. RESULTS: In total, 202 patients were included. CTCA was correct in predicting a normal contralateral coronary artery in 201 of the 202 patients (99.5%). Deferring ICA of the normal contralateral coronary artery on CTCA resulted in a potential reduction in procedure time and dose area product of 4.22 ± 2.67 minutes (61 ± 16% reduction) and 1501 ± 1304 mGy•cm² (29 ± 13% reduction). CONCLUSIONS: In this retrospective study, CTCA was extremely accurate in predicting a normal contralateral coronary artery in patients with LCA- or RCA-limited CAD on CTCA. A potential CTCA-guided ultraselective ICA approach was feasible and would have led to a considerable decrease in procedure time and radiation exposure.

Take it personal! Development and modelling study of an indicated prevention programme for substance use in adolescents and young adults with mild intellectual disabilities and borderline intellectual functioning.

BACKGROUND: This paper describes the theory and development of Take it personal! an indicated prevention programme aimed at reducing substance use in individuals with mild intellectual disabilities and borderline intellectual functioning. METHOD: The process of the development of Take it personal! followed the steps of the Intervention Mapping protocol. Take it personal! is based on the theory that personality traits are an important construct to understand substance use (14-30 years old). A small modelling study was conducted with six adolescents to examine the feasibility, user-friendliness and potential effectiveness of the intervention. RESULTS: The results showed that the intervention has good feasibility and user-friendliness. Post-intervention evaluation of frequency, binge drinking and problematic use indicated that use was lower than at pre-intervention. CONCLUSIONS: Take it Personal! can be a promising preventive intervention designed to reduce substance use in individuals in this target group. A larger scale study is needed to draw further conclusions.

The effectiveness of an indicated prevention programme for substance use in individuals with mild intellectual disabilities and borderline intellectual functioning: results of a quasi-experimental study.

AIMS: To assess the effectiveness of Take it personal!, a prevention programme for individuals with mild intellectual disabilities and borderline intellectual functioning (MID-BIF) and substance use (SU). The prevention programme aims to reduce SU (alcohol, cannabis and illicit drugs) among experimental to problematic substance users. DESIGN: A quasi-experimental design with two arms and a 3-month follow-up. SETTING: Adolescents were recruited from 14 treatment centres in the Netherlands specialized in offering intra- and extramural care for people with MID-BIF and behavioural problems. PARTICIPANTS: Data were collected from 66 individuals with MID-BIF assigned either to the intervention condition (n = 34) or to the control condition (n = 32). INTERVENTIONS: Take it personal! was designed to target four personality traits: sensation-seeking, impulsive behaviour, anxiety sensitivity and negative thinking. For each of these profiles, interventions were developed that were structurally the same but contained different personality-specific materials, games and exercises. The control group received care as usual. MEASUREMENTS: Primary outcomes at 3-month follow-up were frequency of SU, severity of SU and binge drinking. RESULTS: Results showed intervention effects for SU frequency (F(1, 50.43)  = 9.27, P = 0.004) and binge drinking (F(1, 48.02)  = 8.63, P = 0.005), but not for severity of SU (F(1, 42.09)  = 2.20, P = 0.145). CONCLUSIONS: A prevention programme to reduce substance use among experimental to problematic users with mild intellectual disabilities and borderline intellectual functioning helped participants to decrease substance use frequency and binge drinking.

Round-the-clock performance of coronary CT angiography for suspected acute coronary syndrome: Results from the BEACON trial.

OBJECTIVE: To assess the image quality of coronary CT angiography (CCTA) for suspected acute coronary syndrome (ACS) outside office hours. METHODS: Patients with symptoms suggestive of an ACS underwent CCTA at the emergency department 24 hours, 7 days a week. A total of 118 patients, of whom 89 (75 %) presented during office hours (weekdays between 07:00 and 17:00) and 29 (25 %) outside office hours (weekdays between 17:00 and 07:00, weekends and holidays) underwent CCTA. Image quality was evaluated per coronary segment by two experienced readers and graded on an ordinal scale ranging from 1 to 3. RESULTS: There were no significant differences in acquisition parameters, beta-blocker administration or heart rate between patients presenting during office hours and outside office hours. The median quality score per patient was 30.5 [interquartile range 26.0-33.5] for patients presenting during office hours in comparison to 27.5 [19.75-32.0] for patients presenting outside office hours (p=0.043). The number of non-evaluable segments was lower for patients presenting during office hours (0 [0-1.0] vs. 1.0 [0-4.0], p=0.009). CONCLUSION: Image quality of CCTA outside office hours in the diagnosis of suspected ACS is diminished. KEY POINTS: • Quality scores were higher for coronary-CTA during office hours. • There were no differences in acquisition parameters. • There was a non-significant trend towards higher heart rates outside office hours. • Coronary-CTA on the ED requires state-of-the-art scanner technology and sufficiently trained staff. • Coronary-CTA on the ED needs preparation time and optimisation of the procedure.

The effectiveness of narrative versus informational smoking education on smoking beliefs, attitudes and intentions of low-educated adolescents.

OBJECTIVE: This study tests the effectiveness of narrative versus informational smoking education on smoking beliefs, attitudes and intentions of low-educated adolescents. DESIGN: A field experiment with three waves of data collection was conducted. Participants (N = 256) were students who attend lower secondary education. At the first and third waves, they completed a questionnaire. At the second wave, 50.8% of the participants read a smoking education booklet in narrative form and 49.2% read a booklet in informational form. After reading, all participants also completed a questionnaire at wave 2. MAIN OUTCOME MEASURES: Beliefs about negative consequences of smoking, attitudes towards smoking and intentions to smoke were measured. RESULTS: Repeated measures analyses with time as a within-subjects factor and condition as a between-subjects factor showed that beliefs about smoking were more negative at Wave 2 compared to Wave 1, irrespective of condition. However, attitudes towards smoking were more positive at Wave 3 compared to Wave 1 when participants had read the narrative version. CONCLUSION: These results show that narrative smoking education is not more effective than informational smoking education for low-educated adolescents and can even have an unintended effect for this target group by making attitudes towards smoking more positive.

Effectiveness of a selective alcohol prevention program targeting personality risk factors: Results of interaction analyses.

AIM: To explore whether specific groups of adolescents (i.e., scoring high on personality risk traits, having a lower education level, or being male) benefit more from the Preventure intervention with regard to curbing their drinking behaviour. DESIGN: A clustered randomized controlled trial, with participants randomly assigned to a 2-session coping skills intervention or a control no-intervention condition. SETTING: Fifteen secondary schools throughout The Netherlands; 7 schools in the intervention and 8 schools in the control condition. PARTICIPANTS: 699 adolescents aged 13-15; 343 allocated to the intervention and 356 to the control condition; with drinking experience and elevated scores in either negative thinking, anxiety sensitivity, impulsivity or sensation seeking. MEASUREMENTS: Differential effectiveness of the Preventure program was examined for the personality traits group, education level and gender on past-month binge drinking (main outcome), binge frequency, alcohol use, alcohol frequency and problem drinking, at 12months post-intervention. INTERVENTION AND COMPARATOR: Preventure is a selective school-based alcohol prevention programme targeting personality risk factors. The comparator was a no-intervention control. FINDINGS: Intervention effects were moderated by the personality traits group and by education level. More specifically, significant intervention effects were found on reducing alcohol use within the anxiety sensitivity group (OR=2.14, CI=1.40, 3.29) and reducing binge drinking (OR=1.76, CI=1.38, 2.24) and binge drinking frequency (ß=0.24, p=0.04) within the sensation seeking group at 12months post-intervention. Also, lower educated young adolescents reduced binge drinking (OR=1.47, CI=1.14, 1.88), binge drinking frequency (ß=0.25, p=0.04), alcohol use (OR=1.32, CI=1.06, 1.65) and alcohol use frequency (ß=0.47, p=0.01), but not those in the higher education group. Post hoc latent-growth analyses revealed significant effects on the development of binge drinking (ß=-0.19, p=0.02) and binge drinking frequency (ß=-0.10, p=0.03) within the SS personality trait. CONCLUSIONS: The alcohol selective prevention program Preventure appears to have effect on the prevalence of binge drinking and alcohol use among specific groups in young adolescents in the Netherlands, particularly the SS personality trait and lower educated adolescents.

Smoking Education for Low-Educated Adolescents: Comparing Print and Audiovisual Messages.

This study aims to provide insight into which modality is most effective for educating low-educated adolescents about smoking. It compares the persuasive effects of print and audiovisual smoking education materials. We conducted a field experiment with two conditions (print vs. video) and three measurement times (Time 1, Time 2, and Time 3). A total of 221 high school students in the second year of the lowest levels of education in the Netherlands participated at all three time points of the study. Results showed that participants in both conditions had more negative beliefs about smoking after being exposed to the smoking education than before, but there were no differences between the print and video version in this effect. However, the video version did make the attitude toward smoking more negative at Time 3 compared to baseline, whereas the text version did not, which suggests that the video version was more effective for educating low-educated adolescents about smoking.

Absolute coronary blood flow measurement and microvascular resistance in ST-elevation myocardial infarction in the acute and subacute phase.

BACKGROUND/PURPOSE: In a number of patients with acute myocardial infarction (AMI), myocardial hypoperfusion, known as the no-reflow phenomenon, persists after primary percutaneous intervention (PPCI). The aim of this study was to evaluate the feasibility and safety of a new quantitative method of measuring absolute blood flow and resistance within the perfusion bed of an infarct-related artery. Furthermore, we sought to study no-reflow by correlating these measurements to the index of microvascular resistance (IMR) and the area at risk (AR) as determined by cardiac magnetic resonance imaging (CMR). METHODS: Measurements of absolute flow and myocardial resistance were performed in 20 patients with ST-segment elevation myocardial infarction (STEMI), first immediately following PPCI and then again after 3-5days. These measurements used the technique of thermodilution during a continuous infusion of saline. Flow was expressed in ml/min per gram of tissue within the area at risk. RESULTS: The average time needed for measurement of absolute flow, resistance and IMR was 20min, and all measurements could be performed without complication. A higher flow supplying the AR correlated with a lower IMR in the acute phase. Absolute flow increased from 3.14 to 3.68ml/min/g (p=0.25) and absolute resistance decreased from 1317 to 1099 dyne.sec.cm-5/g (p=0.40) between the first day and fifth day after STEMI. CONCLUSIONS: Measurement of absolute flow and microvascular resistance is safe and feasible in STEMI patients and may allow for a better understanding of microvascular (dys)function in the early phase of AMI.

School-based programmes to reduce and prevent substance use in different age groups: What works for whom? Systematic review and meta-regression analysis.

BACKGROUND: Findings from systematic reviews and meta-analyses about the effectiveness of school-based programmes to prevent or reduce substance abuse are inconclusive. We hypothesise that in order to be effective, programmes have to be aligned with the developmental stages of the intended target group (childhood, early, middle, or late adolescence). The present study provides an overview of universal and targeted programmes, while distinguishing four age groups and examining which intervention characteristics are the effective components for the respective groups. METHODS: Databases were searched for controlled studies of school-based programmes, evaluating their effectiveness on either smoking, alcohol or drug use. Multivariate meta-regression analysis was used to analyse the associations between effects and programme characteristics. RESULTS: Our meta-analysis evaluates 288 programmes with a total of 436,180 participants. The findings support our hypothesis that specific aspects of the school-based programmes are effective in some developmental stages, but not for other age groups. The differences in effectiveness are systematically related to psychological and cognitive needs and capacities. DISCUSSION: Our findings highlight the importance of considering a developmental perspective when designing and offering school-based prevention programmes. The various developmental stages offer different possibilities and opportunities for the reduction and prevention of substance use.

The effects of narrative versus non-narrative information in school health education about alcohol drinking for low educated adolescents.

BACKGROUND: Traditionally most health education materials are written in an expository non-narrative format. Scholars have argued that the effectiveness of materials may increase when these texts are replaced by narrative texts, and that the non-narrative texts should be replaced by narrative texts. However, no previous studies have tested these claims in the context of school health education for low educated adolescents. This study aims to do so for an existing preventive health education intervention about alcohol for low educated adolescents. Based on the empirical findings of previous studies, it is expected that the claims about narratives being more effective than non-narrative texts are not true for effects on knowledge. Instead non-narrative texts are expected to have a stronger impact on this outcome variable. For attitude towards alcohol and intention to drink alcohol the claims are expected to be true, because participants are expected to be less aware of the persuasive intent of the narrative texts, which would make them less resistant. As a result, narrative texts are expected to have a stronger effect on attitude and intention. METHODS: This study compares the effects on knowledge, attitude towards alcohol, and intention to drink alcohol of both information formats in a two-condition (non-narrative vs. narrative information) experiment with repeated measures (pre-measurement, immediate post-measurement, and delayed post-measurement). The experiment was conducted amongst 296 students of the two lowest levels of the Dutch secondary education system. RESULTS: The results showed immediate effects on knowledge and attitude towards alcohol, which did not differ between conditions and school levels. These effects did not persist over time. There were no effects on intention to drink alcohol. CONCLUSION: It is concluded non-narrative and narrative information are equally effective in the context of school health education, suggesting the claims that scholars have made about the superior effects of narrative texts are not true. Given the fact that narrative texts are more expensive to develop, policy makers may not be advised to prefer these types of texts over the traditionally used non-narrative texts.

Effectiveness of a selective intervention program targeting personality risk factors for alcohol misuse among young adolescents: results of a cluster randomized controlled trial.

AIM: The effectiveness of Preventure was tested on drinking behaviour of young adolescents in secondary education in the Netherlands. DESIGN: A cluster randomized controlled trial was carried out, with participants assigned randomly to a two-session coping skills intervention or a control no-intervention condition. SETTING: Fifteen secondary schools throughout the Netherlands; seven schools in the intervention and eight schools in the control condition. PARTICIPANTS: A total of 699 adolescents aged 13-15 years participated, 343 allocated to the intervention and 356 to the control condition, with drinking experience and elevated scores in either negative thinking, anxiety sensitivity, impulsivity or sensation-seeking. INTERVENTION AND COMPARATOR: Preventure is a selective school-based alcohol prevention programme targeting personality risk factors. The comparator was a no-intervention control. MEASUREMENTS: The effects of the intervention on the primary outcome past-month binge drinking, and the secondary outcomes binge drinking frequency, alcohol use, alcohol frequency and problem drinking, were examined. The primary analyses of interest were intervention main effects at 12 months post-intervention. In addition, intervention effects on the linear development of binge drinking using a latent-growth curve approach were examined. FINDINGS: Binge drinking rates were not significantly different between the intervention (42.9%) and control group (49.2%) at 12 months follow-up [odds ratio (OR) = 1.05, confidence interval (CI) = 0.99, 1.11]. Intention-to-treat analyses revealed no significant intervention effects on alcohol use (53.9 versus 61.5%; OR = 0.99, CI = 0.86, 1.14) and problem drinking (37.0 versus 44.7%; OR = 1.03, CI = 0.92, 1.10) at 12 months follow-up. The post-hoc latent-growth analyses revealed significant effects on the development of binge drinking (ß = -0.16, P = 0.05), and binge drinking frequency (ß = -0.14, P = 0.05). CONCLUSION: The alcohol prevention programme, Preventure, appears to have little or no effect on overall prevalence of binge drinking in adolescents in the Netherlands but may reduce the development of binge drinking over time.

Substance use outcomes in the Healthy School and Drugs program: results from a latent growth curve approach.

AIM: To assess the effectiveness of the Healthy School and Drugs (HSD) program for secondary schools on the development of substance use among Dutch early adolescents and to explore whether boys, adolescents of lower educational backgrounds, or adolescents high on personality risk traits, would benefit more from the HSD program than others. DESIGN: Randomized clustered trial with two intervention conditions (i.e., lessons and integral) among a general population of adolescents in the Netherlands. PARTICIPANTS: A total of 3784 students of 23 Dutch secondary schools. MEASUREMENTS: Structured digital questionnaires were administered pre-intervention and at 8, 20, and 32months follow-ups. The outcome measure was the rate of change in substance use across follow-ups. Differential effectiveness of the HSD program was examined for sex, educational level, and personality traits. FINDINGS: Our results show no HSD intervention effects on the development of substance use. Sex, education level, and personality characteristics of the participants did not moderate the intervention effects. CONCLUSION: The absence of effects of the Healthy School and Drugs program on the development of substance use indicates that the program should be renewed and redeveloped.

Effectiveness of the 'Healthy School and Drugs' prevention programme on adolescents' substance use: a randomized clustered trial.

AIM: To evaluate the effectiveness of the Healthy School and Drugs programme on alcohol, tobacco and marijuana use among Dutch early adolescents. DESIGN: Randomized clustered trial with two intervention conditions (i.e. e-learning and integral). SETTING: General population of 11-15-year-old adolescents in the Netherlands. PARTICIPANTS: A total of 3784 students of 23 Dutch secondary schools. MEASUREMENTS: Structured digital questionnaires were administered pre-intervention and at 32 months follow-up. The primary outcome measures were new incidences of alcohol (life-time and 1-month prevalence), tobacco (life-time and 1-month prevalence) and marijuana use (life-time prevalence). FINDINGS: Main effect analyses showed no programme effects on incidences of alcohol consumption (life-time prevalence: e-learning condition: B = 0.102, P = 0.549; integral condition: B = -0.157, P = 0.351; 1-month prevalence: e-learning condition: B = 0.191, P = 0.288; integral condition: B = -0.140, P = 0.445), tobacco consumption (life-time prevalence: e-learning condition: B = 0.164, P = 0.444; integral condition: B = 0.160, P = 0.119; 1-month prevalence: e-learning condition: B = 0.088, P = 0.746; integral condition: B = 0.261, P = 0.093), or marijuana consumption (life-time prevalence: e-learning condition: B = 0.070, P = 0.732; integral condition: B = 0.186, P = 0.214). CONCLUSION: The non-significant impact of the Healthy School and Drugs programme (a Dutch school-based prevention programme for early adolescents) on incidences of alcohol, tobacco and marijuana use indicates that the programme is either ineffective or implemented inadequately.

Mediational relations of substance use risk profiles, alcohol-related outcomes, and drinking motives among young adolescents in the Netherlands.

AIM: To examine the mediation by drinking motives of the association between personality traits (negative thinking, anxiety sensitivity, impulsivity, and sensation seeking) and alcohol frequency, binge drinking, and alcohol-related problems using a sample of students (n=3053) aged between 13 and 15, who reported lifetime use of alcohol. METHOD: Structural equation modeling was used to examine the relationship between personality traits and alcohol-related outcomes. The Model Indirect approach was used to examine the hypothesized mediation by drinking motives of the association between personality traits and alcohol-related outcomes. RESULTS: In this study among young adolescents, coping motives, social motives and enhancement motives played a prominent mediating role between personality and the alcohol outcomes. Multi-group analyses revealed that the role of drinking motives in the relation between personality and alcohol outcomes were largely similar between the sexes, though there were some differences found for binge drinking. More specifically, for young males, enhancement motives seems to play a more prominent mediation role between personality and binge drinking, while for young females, coping motives play a more mediating role between personality and binge drinking. Few mediation associations were found for conformity motives, and no relationships were found between anxiety sensitivity and drinking motives. DISCUSSION: Already in early adolescence, personality traits are found to be associated with drinking motives, which in turn are related to alcohol use. This study provides indications that it is important to intervene in early adolescence with interventions focusing on personality traits in combination with drinking motives.

Are there reciprocal relationships between substance use risk personality profiles and alcohol or tobacco use in early adolescence?

AIM: We examined whether reciprocal relationships were present between the SURPS personality profiles and substance use in early adolescence. METHODS: Longitudinal data of four-waves of a broader effectiveness study were used from 1068 early adolescents. RESULTS: Our cross-lagged models indicated that sensation seeking and impulsivity show strongest reciprocal associations with substance use during early adolescence. In contrast, no reciprocity was present between substance use and anxiety sensitivity and only one reciprocal relationship was present between substance use and hopelessness. CONCLUSIONS: In trying to prevent early adolescents from alcohol and tobacco use, it might be of key importance to acknowledge the mutual influence between certain personality profiles and substance use. Specifically, sensation seeking and impulsivity are relevant during early adolescence and awareness of early adolescents' vulnerability for these personality predispositions is warranted.

Do substance use risk personality dimensions predict the onset of substance use in early adolescence? A variable- and person-centered approach.

Various studies found personality to be related to substance use, but little attention is paid to the role of personality risk dimensions with regard to an early onset of alcohol, tobacco, and marijuana use. Therefore, the current study used a variable-centered approach to examine whether anxiety sensitivity, hopelessness, sensation seeking, and impulsivity predict the onset of alcohol, tobacco, and marijuana use in early adolescence. Additionally, we adopted a person-centered approach to examine whether different personality subgroups could be identified, and whether these subgroups would be predictive of substance use. For that purpose, longitudinal data of a broader effectiveness study were used from 758 early adolescents (53 % female) aged 11-14 years. Structural equation models showed that hopelessness and sensation seeking were predictive of having ever used alcohol and tobacco. Also, sensation seeking was predictive of marijuana use. Latent profile analyses on the first wave data revealed a three-profile solution for boys (i.e., resilients, internalizers, and externalizers) and a two-profile solution for girls (i.e., resilients and internalizers). In contrast to our expectation, further analyses revealed no significant differences in substance use between the different subprofiles for both boys and girls. The separate personality dimensions thus seem more relevant in predicting the onset of substance use compared to the personality profiles. However, the personality profiles might be informative in explaining more excessive substance use behaviors.

Evaluating a selective prevention programme for binge drinking among young adolescents: study protocol of a randomized controlled trial.

BACKGROUND: In comparison to other Europe countries, Dutch adolescents are at the top in drinking frequency and binge drinking. A total of 75% of the Dutch 12 to 16 year olds who drink alcohol also engage in binge drinking. A prevention programme called Preventure was developed in Canada to prevent adolescents from binge drinking. This article describes a study that aims to assess the effects of this selective school-based prevention programme in The Netherlands. METHODS: A randomized controlled trial is being conducted among 13 to 15-year-old adolescents in secondary schools. Schools were randomly assigned to the intervention and control conditions. The intervention condition consisted of two 90 minute group sessions, carried out at the participants' schools and provided by a qualified counsellor and a co-facilitator. The intervention targeted young adolescents who demonstrated personality risk for alcohol abuse. The group sessions were adapted to four personality profiles. The control condition received no further intervention above the standard substance use education sessions provided in the Dutch national curriculum. The primary outcomes will be the percentage reduction in binge drinking, weekly drinking and drinking-related problems after three specified time periods. A screening survey collected data by means of an Internet questionnaire. Students have completed, or will complete, a post-treatment survey after 2, 6, and 12 months, also by means of an online questionnaire. DISCUSSION: This study protocol presents the design and current implementation of a randomized controlled trial to evaluate the effectiveness of a selective alcohol prevention programme. We expect that a significantly lower number of adolescents will binge drink, drink weekly, and have drinking-related problems in the intervention condition compared to the control condition, as a result of this intervention. TRIAL REGISTRATION: This trial is registered in the Dutch Trial Register (Cochrane Collaboration) as NTR1920.

Effectiveness of the universal prevention program 'Healthy School and Drugs': study protocol of a randomized clustered trial.

BACKGROUND: Substance use is highly prevalent among Dutch adolescents. The Healthy School and Drugs program is a nationally implemented school-based prevention program aimed at reducing early and excessive substance use among adolescents. Although the program's effectiveness was tested in a quasi-experimental design before, many program changes were made afterwards. The present study, therefore, aims to test the effects of this widely used, renewed universal prevention program. METHODS/DESIGN: A randomized clustered trial will be conducted among 3,784 adolescents of 23 secondary schools in The Netherlands. The trial has three conditions; two intervention conditions (i.e., e-learning and integral) and a control condition. The e-learning condition consists of three digital learning modules (i.e., about alcohol, tobacco, and marijuana) that are sequentially offered over the course of three school years (i.e., grade 1, grade 2, and grade 3). The integral condition consists of parental participation in a parental meeting on substance use, regulation of substance use, and monitoring and counseling of students' substance use at school, over and above the three digital modules. The control condition is characterized as business as usual. Participating schools were randomly assigned to either an intervention or control condition.Participants filled out a digital questionnaire at baseline and will fill out the same questionnaire three more times at follow-up measurements (8, 20, and 32 months after baseline). Outcome variables included in the questionnaire are the percentage of binge drinking (more than five drinks per occasion), the average weekly number of drinks, and the percentage of adolescents who ever drunk a glass of alcohol and the percentage of adolescents who ever smoked a cigarette or a joint respectively for tobacco and marijuana. DISCUSSION: This study protocol describes the design of a randomized clustered trial that evaluates the effectiveness of a school-based prevention program. We expect that significantly fewer adolescents will engage in early or excessive substance use behaviors in the intervention conditions compared to the control condition as a direct result of the intervention. We expect that the integral condition will yield most positive results, compared with the e-learning condition and control condition. TRIAL REGISTRATION: The protocol for this study is registered with the Nederlands Trial Register NTR1516.