X:IT – evaluation of a school-based intervention to reduce smoking

ISRCTN ISRCTN77415416
DOI https://doi.org/10.1186/ISRCTN77415416
Secondary identifying numbers N/A
Submission date
16/01/2012
Registration date
18/04/2012
Last edited
19/09/2016
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Mental and Behavioural Disorders
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Background and study aims
Although the harmful effects of tobacco have been known for many years, we have not succeeded in preventing young people from taking up smoking. Many young people still start smoking, and the number of young smokers has only decreased slightly during the last 10 years. Starting smoking at age 15 increases your risk of becoming a daily smoker as an adult. Therefore, it is very important to prevent smoking among children and young adolescents. The aim of this study is to develop and test a school-based anti-smoking program to reduce the number of smokers by 25% over a three-year period.

Who can participate?
Students in grade 7 at the start of the study

What does the study involve?
Participating schools are randomly allocated to either the intervention group or the control group. Students at the intervention group schools receive the anti-smoking program, whereas students at the control group schools do not. The anti-smoking program has three main components: eight anti-smoking lessons a year; students sign a contract promising to stay smoke free for the next year; and no smoking is allowed on the school premises. Furthermore, the study includes workshops for the staff, newsletters for the schools, a website with guidelines for parents and information for schools, and presentation of the study at parent school meetings each year. The study runs for three years (grade 7-9), with an annual follow-up in the spring of each year to measure how many students smoke.

What are the possible benefits and risks of participating?
The schools receive free educational materials and free workshops introducing the study and later sharing experiences of the study. Furthermore, participating schools receive a report describing the health behaviours of the adolescents in their school. The students among other things increase their knowledge about the risks of smoking, the social factors influencing decisions to smoke or not, and the role of the media in adolescent smoking. All students who stay smoke-free for a year have the chance to win a prize. There are no known risks to participants.

Where is the study run from?
Centre for Intervention Research in Health Promotion and Disease Prevention at the National Institute of Public Health, University of Southern Denmark

When is the study starting and how long is it expected to run for?
January 2010 to June 2013

Who is funding the study?
1. The Danish Cancer Society (Denmark)
2. Centre for Intervention Research in Health Promotion and Disease Prevention (Denmark)

Who is the main contact?
Anette Andersen
anan@niph.dk

Study website

Contact information

Mrs Anette Andersen
Scientific

Øster Farimagsgade 5A
Copenhagen
1353
Denmark

Phone +45 (0)65 50 77 77
Email anan@niph.dk

Study information

Study designCluster randomized controlled design with three-year follow-up
Primary study designInterventional
Secondary study designCluster randomised trial
Study setting(s)School
Study typePrevention
Participant information sheet Patient information can be found at www.xit-web.dk/materialer/pjecer-og-foraeldreinformation (Danish)
Scientific titleX:IT - a three-year multi-component, school-based, cluster randomized trial to reduce smoking among 13-15 year olds in Denmark
Study acronymX:IT
Study objectivesTo reduce prevalence of smokers by 25% over a three-year period, at grade 9 in intervention schools compared to control schools.
Ethics approval(s)There is no formal institution for ethical assessment and approval of questionnaire-based population studies in Denmark. The study is registered at the Danish Data Protection Agency, 15/04/2010, ref: 2010-54-0930
Health condition(s) or problem(s) studiedSmoking
InterventionStudents in grade 7, 8 and 9 at 51 intervention schools receive the X:IT intervention program during the school years 2010/11, 2011/12 and 2012/13, whereas students at 43 control schools do not receive any intervention. The intervention lasts for three school years, e.g. from August 2010 till May 2013. Baseline data was collected August 2010, first follow-up survey May/June 2011, second follow-up survey May/June 2012 and third follow-up survey May/June 2013. The intervention focuses at three arenas/levels which influence adolescents’ lives:
1. Parent involvement
1.1. Students and parents sign a smoke-free contract each year for three years
1.2. Parents are encouraged to undertake a smoke-free dialogue with their child each year for three years
2. Smoke free curriculum, 8 lessons every year for three years with new teaching materials, for more information see www.op-i-roeg.dk
3. Smoke free schools throughout the intervention period. Information for municipalities, schools and parents are available on www.xitweb.dk
Intervention typeBehavioural
Primary outcome measure1. Frequency of smokers at grade seven, eight and nine measured at baseline, 1,2 and 3 follow-up by student self-reported questionnaires
1.1. Measures of smoking will be supplemented by analyses of number of cigarettes smoked and age at debut
1.2. Frequency of smoking will be analyzed at individual, class and school level
Secondary outcome measuresIntermediate outcomes of the intervention:
1. Individual outcomes:
1.1. Enhanced self-efficacy for smoking
1.2. Increased knowledge about smoking
1.3. Change in norms and attitudes towards smoking
1.4. Performed smoke-free dialogue with parents
2. Group level outcomes
2.1. Increase probability of smoke-free environments at home and at schools
2.2. Changed norms and attitudes against smoking at schools
2.3. Reduce availability of tobacco
2.4. Increase probability of not being exposed to smoking students, teachers and parents
Analyses in the project will have a special focus on subgroup analyses especially gender and socioeconomic position.
3. Sustainability
3.1. At second follow-up it will be measured whether participation in Project X:IT has initiated environmental changes and capacity building by questionnaires to project coordinators at schools and in municipalities. Furthermore, we will measure whether the project continues at intervention schools and is initiated at control schools.
4. Differences in frequency of drunkenness and marijuana use between intervention and control schools
5. Differences in students’ wellbeing between intervention and control schools
Overall study start date01/01/2010
Completion date30/06/2013

Eligibility

Participant type(s)Patient
Age groupChild
SexBoth
Target number of participants4.468 students (2538 in the intervention group, 1930 in the control group) at 51 intervention schools and 43 control schools from 17 municipalities cross nationally
Key inclusion criteriaAll students at participating schools enrolled in grade 7 at baseline (August 2010)
Key exclusion criteria1. Schools not run by municipalities
2. Schools for children with special needs
Date of first enrolment01/01/2010
Date of final enrolment30/06/2013

Locations

Countries of recruitment

  • Denmark

Study participating centre

Øster Farimagsgade 5A
Copenhagen
1353
Denmark

Sponsor information

Centre for Intervention Research in Health Promotion and Disease Prevention (Denmark)
Government

National Institute of Public Health
University of Southern Denmark
Øster Farimagsgade 5A
Copenhagen
1353
Denmark

Phone +45 (0)65 50 77 77
Email anan@niph.dk
Website http://www.interventionsforskning.dk/
ROR logo "ROR" https://ror.org/03yrrjy16

Funders

Funder type

Government

Kræftens Bekæmpelse
Government organisation / Associations and societies (private and public)
Alternative name(s)
Danish Cancer Society, The Danish Cancer Society, DCS
Location
Denmark
Center for Intervention Research in Health Promotion and Disease Prevention (Denmark)

No information available

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot provided at time of registration
Publication and dissemination planNot provided at time of registration
IPD sharing plan

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Protocol article protocol 28/05/2014 Yes No
Results article results 17/09/2016 Yes No

Editorial Notes

19/09/2016: Publication reference added.
11/08/2016: Plain English summary added.