Condition category
Mental and Behavioural Disorders
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
To reduce tobacco-related disease it is crucial to prevent adolescents from starting smoking. Web-based interventions are suitable for health education and their effectiveness has been demonstrated across a wide range of conditions. They provide tailored feedback based on an individual’s answers to a questionnaire. These messages are more likely to influence the person’s behaviour. The aim of this study is to test a new web-based program called Smoke Alert at schools and to assess its effectiveness for the prevention of smoking uptake among adolescents.

Who can participate?
Students from high schools in the Netherlands, aged between 12 and 30.

What does the study involve?
Schools are randomly allocated into either the experimental group or the control group. The experimental group complete an online questionnaire and receive tailored advice. The control group complete a short questionnaire that measures smoking behaviour and intention to start smoking. Age, gender and educational level are also assessed. The students in the control group do not receive any advice. Assessments are made at the start of the study and after six months.

What are the possible benefits and risks of participating?
Students participating in this study have the opportunity to obtain free personal tailored advice with information on how to refuse a cigarette or how to stop smoking. Students in the control group were offered the chance to take part in the Smoke Alert intervention six months later. This way, all students who are participating are offered the Smoke Alert intervention. There are no risks of participating in this study.

Where is the study run from?
University Maastricht (Netherlands).

When is the study starting and how long is it expected to run for?
April to December 2011.

Who is funding the study?
Dutch Ministry of Health, Welfare and Sport (Netherlands).

Who is the main contact?
Sanne de Josselin de Jong (
Hein de Vries (

Trial website

Contact information



Primary contact

Prof Hein de Vries


Contact details

University Maastricht
P.O. Box 616
6200 MD



Additional contact

Dr Sanne de Josselin de Jong


Contact details

University Maastricht
Department of Health Promotion and Health Education
6200 MD

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Effects of a randomized web-based computer-tailored smoking prevention trial for Dutch adolescents: a cluster randomized controlled trial


Study hypothesis

The personalized feedback messages that adolescents receive on their computer screen in the tailored condition result in lower uptake of smoking after six months compared to no feedback messages.

Ethics approval

Based on the guidelines of the local Ethics Committee (no treatment is involved and filling out the questionnaire do not cause mental load), medical ethical approval is not sought. The students, their parents and teachers receive written information on methods. The students voluntary take part in the intervention and they are guaranteed anonymity.

Study design

Cluster randomized controlled trial

Primary study design


Secondary study design

Cluster randomised trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Smoking initiation


The study compares the effect of a web-based tailored smoking prevention intervention with a control condition.

Participants in the experimental condition receive a web-based tailored intervention called 'Smoke Alert', consisting of a questionnaire followed by a tailored advice. The intervention incorporates concepts from several cognitive models. Smoke Alert measures attitude towards smoking and quitting, perceived social influence -consisting of social pressure, social modeling and social norms- and self-efficacy not to smoke. Smoke Alert also tailors to intention to start or quit smoking and actions plans to quit smoking or refuse a cigarette. Other factors that are assessed in the Smoke Alert-questionnaire are age, gender, educational level and level of physical activity.

After filling out the questionnaire, respondents receive personal, automatized feedback. This feedback is provided on each specific determinant and the students' response to specific items is used for this (e.g. a chapter for feedback on action plans with a short advice for each specific action plan).

Participants in the control condition do not receive a tailored advice.

Intervention type



Drug names

Primary outcome measures

Smoking behaviour - Respondents are asked to select a statement that best described their behaviour. They are categorised as non-smokers if they indicate to have never smoked a puff; to have tried smoking but not anymore or to have stopped smoking.

Baseline assessment and follow-up measurement at six months

Secondary outcome measures

Intention to start smoking. The students are asked to select a statement that best described their situation with options ranging from 'I think I will start smoking within 1 month' (7) to 'I know for sure I won't ever start smoking' (1).

Baseline assessment and follow-up measurement at six months

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

Participants in this study were students from high schools in the Netherlands, aged between 12 and 30.

Participant type


Age group




Target number of participants

1940 students

Participant exclusion criteria

Self-reported smoking and previous exposure to the intervention

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

University Maastricht
6200 MD

Sponsor information


University Maastricht (Netherlands)

Sponsor details

P.O. Box 616
6200 MD

Sponsor type




Funder type


Funder name

Dutch Ministry of Health, Welfare and Sport (Netherlands)

Alternative name(s)

Dutch Ministry of Health, Welfare and Sport, VWS

Funding Body Type

government organisation

Funding Body Subtype




Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

2014 results in:

Publication citations

  1. Results

    de Josselin de Jong S, Candel M, Segaar D, Cremers HP, de Vries H, Efficacy of a Web-based computer-tailored smoking prevention intervention for Dutch adolescents: randomized controlled trial., J. Med. Internet Res., 2014, 16, 3, e82, doi: 10.2196/jmir.2469.

Additional files

Editorial Notes