Plain English Summary
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
Trial website
Contact information
Type
Scientific
Primary contact
Mrs Anette Andersen
ORCID ID
Contact details
Øster Farimagsgade 5A
Copenhagen
1353
Denmark
+45 (0)65 50 77 77
anan@niph.dk
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
N/A
Study information
Scientific title
X:IT - a three-year multi-component, school-based, cluster randomized trial to reduce smoking among 13-15 year olds in Denmark
Acronym
X:IT
Study hypothesis
To reduce prevalence of smokers by 25% over a three-year period, at grade 9 in intervention schools compared to control schools.
Ethics approval
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
Study design
Cluster randomized controlled design with three-year follow-up
Primary study design
Interventional
Secondary study design
Cluster randomised trial
Trial setting
Schools
Trial type
Prevention
Patient information sheet
Patient information can be found at www.xit-web.dk/materialer/pjecer-og-foraeldreinformation (Danish)
Condition
Smoking
Intervention
Students 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 type
Behavioural
Phase
Drug names
Primary outcome measures
1. 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 measures
Intermediate 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 trial start date
01/01/2010
Overall trial end date
30/06/2013
Reason abandoned
Eligibility
Participant inclusion criteria
All students at participating schools enrolled in grade 7 at baseline (August 2010)
Participant type
Patient
Age group
Child
Gender
Both
Target number of participants
4.468 students (2538 in the intervention group, 1930 in the control group) at 51 intervention schools and 43 control schools from 17 municipalities cross nationally
Participant exclusion criteria
1. Schools not run by municipalities
2. Schools for children with special needs
Recruitment start date
01/01/2010
Recruitment end date
30/06/2013
Locations
Countries of recruitment
Denmark
Trial participating centre
Øster Farimagsgade 5A
Copenhagen
1353
Denmark
Sponsor information
Organisation
Centre for Intervention Research in Health Promotion and Disease Prevention (Denmark)
Sponsor details
National Institute of Public Health
University of Southern Denmark
Øster Farimagsgade 5A
Copenhagen
1353
Denmark
+45 (0)65 50 77 77
anan@niph.dk
Sponsor type
Government
Website
Funders
Funder type
Government
Funder name
Kræftens Bekæmpelse
Alternative name(s)
Danish Cancer Society
Funding Body Type
private sector organisation
Funding Body Subtype
other non-profit
Location
Denmark
Funder name
Center for Intervention Research in Health Promotion and Disease Prevention (Denmark)
Alternative name(s)
Funding Body Type
Funding Body Subtype
Location
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 protocol in: http://www.ncbi.nlm.nih.gov/pubmed/24886206
2016 results in: http://www.ncbi.nlm.nih.gov/pubmed/27640187
Publication citations
-
Protocol
Andersen A, Bast LS, Ringgaard LW, Wohllebe L, Jensen PD, Svendsen M, Dalum P, Due P, Design of a school-based randomized trial to reduce smoking among 13 to 15-year olds, the X:IT study., BMC Public Health, 2014, 14, 518, doi: 10.1186/1471-2458-14-518.