Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.
UNKNOWN
NA
400 participants
INTERVENTIONAL
2018-09-18
2022-06-01
Brief Summary
Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.
In detail, it is aimed for to examine changes in (daily) moderate to vigorous physical activity in adolescents' friendship dyads following (a) an individual planning intervention, (b) a collaborative planning intervention or (c) one of the two no-planning control conditions. Changes in (daily) physical activity will be examined over a period of 6-months. By investigating the intervention effect systematically by means of daily diaries, long-term follow-ups and objective measurements this project will provide a novel knowledge about individual self-regulating mechanism and social exchange processes as the mediating mechanism of the effectiveness of individual and collaborative planning for health behavior change in adolescents. DESIGN: Single-blind four-arm parallel-group cluster-randomized controlled trial with longitudinal design. The assessment of the main and secondary outcomes is conducted at the baseline, at 1 week after the first intervention session, and at 1-, and 6-month follow-ups. The intervention consists of one planning session and one booster session after 1-month. PARTICIPANTS: The sample will consist of 400 friendship dyads between 14 and 18 years of age. A cluster-randomization will assign participants to one of the two planning groups (collaborative or individual) or one of the two control groups. Both partners of the friendship dyad will complete all questionnaires. OUTCOMES: Physical activity constitutes the main outcome, whereas self-regulatory strategies like planning, self-efficacy, as well as social exchange processes like social support are secondary outcomes.
Detailed Description
Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.
Research question 1: Is planning an effective strategy to promote PA in adolescents when using daily based measures of PA and long-term follow-ups?
Hypothesis 1.1. Adolescents, who take part in one of the two planning interventions, will show higher levels of (self-reported/objectively measured) PA compared to the control groups when comparing PA on a daily basis, one week (directly after the intervention), one month (after the booster session) and six months after the intervention.
Hypothesis 1.2. Adolescents in the individual and collaborative planning intervention will report higher PA one month and six months after the intervention compared to the control groups.
Research question 2: Do collaborative and individual planning differ regarding their effectiveness to promote PA in adolescents?
Hypothesis 2.1. Adolescents, who take part in the collaborative planning intervention, will show higher levels of (self-reported/objectively measured) PA compared to the individual planning intervention when comparing PA on a daily basis, one week (directly after the intervention), one month (after the booster session) and six months after the intervention.
Hypothesis 2.2. Adolescents in the collaborative planning intervention will report higher PA one month and six months after the intervention compared to the individual planning intervention and the control groups.
Research question 3: Does the planning intervention increase individual self-regulatory processes over time?
Hypothesis 3.1. Adolescents in the individual and collaborative planning intervention will report higher daily self-efficacy one week (directly after the intervention), one month (after the booster session) and six months after the intervention compared to the control groups.
Hypothesis 3.2. Adolescents in the individual and collaborative planning intervention will report higher self-efficacy one month and six months after the intervention compared to the control groups.
Hypothesis 3.3. Adolescents in the individual and collaborative planning intervention will report higher daily (self-reported) planning one week (directly after the intervention), one month (after the booster session) and six months after the intervention compared to the control groups.
Hypothesis 3.4. Adolescents in the individual and collaborative planning intervention will report higher (self-reported) planning one month and six months after the intervention compared to the control groups.
Research question 4: Does the collaborative planning intervention increase social exchange processes over time?
Hypothesis 4.1. Adolescents in the collaborative planning intervention will report higher daily levels of social support one week (directly after the intervention), one month (after the booster session) and six months after the intervention compared to the individual planning condition and the control groups.
Hypothesis 4.2. Adolescents in the collaborative planning intervention will report higher levels of social support one month and six months after the intervention compared to the individual planning condition and the control groups.
Research question 5: What are the underlying mechanisms of the planning interventions in adolescents regarding PA?
Hypothesis 5.1. The effect of the individual planning intervention on daily (self-reported/objectively measured) PA, one week (directly after the intervention), one month (after the booster session) and six months later is mediated by changes in daily individual self-regulatory strategies like self-efficacy, and self-reported planning.
Hypothesis 5.2. The effect of the individual planning intervention on (self-reported) PA, one month and six months later is mediated by changes in individual self-regulatory strategies like self-efficacy, and self-reported planning.
Hypothesis 5.3. The effect of the collaborative planning intervention on daily (self-reported/objectively measured) PA, one week (directly after the intervention), one month (after the booster session) and six months later is mediated by changes in daily levels of social support, as well as by changes in daily individual self-regulatory strategies like self-efficacy, and self-reported planning.
Hypothesis 5.4. The effect of the collaborative planning intervention on (self-reported) PA, one month and six months later is mediated by changes in levels of social support and changes in individual self-regulatory strategies like self-efficacy, and self-reported planning.
Design: This study is designed as a single-blind four-arm parallel-group cluster randomized controlled trial with longitudinal design. The design will comprise a baseline assessment, the intervention and two follow-ups one and six months after baseline. The sample will consist of 400 friendship dyads between 14 and 18 years of age. Recruitment will take place at schools. Therefore, a cluster randomization based upon the schools of all dyads to the four intervention arms is used. In addition, a blocked randomization is used to ensure an equal allocation ration of all a school types (level A; secondary school; vocational school) to the study conditions. All participants being interested in the study, fill in a pre-screening online questionnaire (runin) with the inclusion and exclusion criteria. Afterwards, the friendship dyad will be contacted to make an appointment for the first baseline measurement (T1). Subsequently, adolescents fill in the end-of day diaries and wear the accelerometers for eight days. After this week, the dyads will be invited for the intervention session (T2). All participants will receive an education and general motivational treatment to enhance daily physical activity and are then blocked randomly assigned to one of four intervention conditions: (a) a collaborative planning intervention, in which both adolescents form action and coping plans together to increase daily physical activity together, or (b) an individual planning intervention, in which both adolescents form such action and coping plans individually, or (c) a no-planning control condition, in which both adolescents perform a distraction task together, or (d) a no-planning control condition, in which both adolescents perform a distraction task alone, separately from each other. After the intervention session all adolescents fill in the end-of day diaries and wear the accelerometers for the following seven days. Adolescents of the two planning conditions will receive weekly messages to rethink and adapt their plans with the request to send them to the experimenters. One month (T3) after the intervention all participants are invited for the booster session. Adolescents of the two planning conditions will work on their plans again to adapt or improve them. After this session all participants fill in the end-of day diaries and wear the accelerometers for the following seven days. On a monthly basis all participants of the planning conditions will receive messages to rethink and adapt their plans with the request to send them to the experimenters. Six month after the intervention the participants will be invited to the six-month follow-up (T4). Again, all participants subsequently fill in the end-of day diaries and wear the accelerometers for the following seven days. During all sessions and the daily diaries both partners of the friendship dyad will complete all questionnaires. Self-reports of PA and sedentary behavior, as well as objectively measured PA as the main constructs will be assessed at all time points. Self-regulation constructs (e.g., self-efficacy) will be assessed at time point 1, 3, and 4, whereas social support will be assessed at time T2-T4. In addition, the body weight, height, and body fat tissue will be measured objectively at T1, T3, and T4. The Ethics Committee of the Faculty of Arts and Social Sciences of the University of Zurich, ref: 2017.10.3 approved the study.
Results of this project aims at closing the empirical gap of the question whether planning interventions of PA in adolescents are successful and which planning intervention is the most effective one. By investigating this systematically by means of daily diaries, long-term follow-ups and objective measurements this study will provide novel knowledge about social exchange processes as the mediating mechanism of the effectiveness of collaborative planning for health behavior change in adolescents. Consequently, effective theory-based and evidence-based interventions to promote PA in adolescents can be developed.
Conditions
See the medical conditions and disease areas that this research is targeting or investigating.
Study Design
Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.
RANDOMIZED
PARALLEL
PREVENTION
SINGLE
Study Groups
Review each arm or cohort in the study, along with the interventions and objectives associated with them.
Individual planning
An education and general motivational treatment is provided to each participant. Afterwards, participants are filling in the planning forms, referring to their individual physical activity. Both members of the dyad form up to three own individual plans. They are not allowed to speak to each other. The following behavior change techniques (BCT) are included in the planning intervention protocol: action planning, barrier identification, problem solving (coping planning). Interventions: Behavioral: Individual planning. Behavioral: Education and motivation. Active Comparator: No planning intervention, individual distraction task.
Individual planning
Each participant forms up to three action and up to three coping plans individually, without consulting the participating friend, but discussing the plans with the experimenter. CONTENT: The planning materials and forms have the following sections: (a) information on the importance of planning (b) instructions of what should be included in a good plan (the when, where, and how components), (c) formulating action and coping plans based on the if-then structure. Action plans (referring to when, when, and how the individual will act) as well as coping plans (referring to how to overcome potential difficulties, risky situations or temptations to not engage in physical activity).
Education and motivation treatment
Adolescents will watch a movie from the Federal Office of Public Health Switzerland including the guidelines of physical activity (PA) for adolescents. All adolescents respond to a quiz afterwards. After the quiz, the experimenter repeats the guidelines for PA based on a brochure that all adolescents can take home with them. In addition, the experimenter asks for barriers and benefits of PA the adolescents perceive. Next to it, the experimenter explains that a weight gain might be possible due to PA in the beginning. Furthermore, the experimenter presents how the data of the accelerometer should look like if one is sufficiently physical active. As a last part self-efficacy as an important aspect of goal success is mentioned. The materials exclude any planning statements.
Collaborative planning
An education and general motivational treatment is provided to each participant. Afterwards, participants are filling in the planning forms together, referring to their joint physical activity. The friendship dyad forms up to three joint plans about engaging in PA together. The following behavior change techniques (BCT) are included in the planning intervention protocol: action planning, barrier identification, problem solving (coping planning). Interventions: Behavioral: Collaborative planning. Behavioral: Education and motivation. Active Comparator: No planning intervention, collaborative distraction task.
Collaborative planning
Both friends together create up to three if-then plans on when, where, and how both will implement PA together. In addition, up to three coping plans will be formed together. This jointly developed plan is discussed with the experimenter. CONTENT: The planning materials and forms have the following sections: (a) information on the importance of planning (b) instructions of what should be included in a good plan (the when, where, and how components), (c) formulating action and coping plans based on the if-then structure. Action plans refers to when, when, and how the individual will act) as well as coping plans (referring to how to overcome potential difficulties, risky situations or temptations to not engage in PA). All materials are formulated using the plural.
Education and motivation treatment
Adolescents will watch a movie from the Federal Office of Public Health Switzerland including the guidelines of physical activity (PA) for adolescents. All adolescents respond to a quiz afterwards. After the quiz, the experimenter repeats the guidelines for PA based on a brochure that all adolescents can take home with them. In addition, the experimenter asks for barriers and benefits of PA the adolescents perceive. Next to it, the experimenter explains that a weight gain might be possible due to PA in the beginning. Furthermore, the experimenter presents how the data of the accelerometer should look like if one is sufficiently physical active. As a last part self-efficacy as an important aspect of goal success is mentioned. The materials exclude any planning statements.
Individual distraction task
An education and general motivational treatment is provided to each participant. Afterwards, participants have to interpret a short video showing scenes of two different superhero movies. Several questions will be asked about characteristics of the two super heroes in the movie and whether these heroes are comparable. Each participant watches the movie alone and answers all questions by him/herself. Both members of the dyad are not allowed to speak to each other.
Education and motivation treatment
Adolescents will watch a movie from the Federal Office of Public Health Switzerland including the guidelines of physical activity (PA) for adolescents. All adolescents respond to a quiz afterwards. After the quiz, the experimenter repeats the guidelines for PA based on a brochure that all adolescents can take home with them. In addition, the experimenter asks for barriers and benefits of PA the adolescents perceive. Next to it, the experimenter explains that a weight gain might be possible due to PA in the beginning. Furthermore, the experimenter presents how the data of the accelerometer should look like if one is sufficiently physical active. As a last part self-efficacy as an important aspect of goal success is mentioned. The materials exclude any planning statements.
Collaborative distraction task
An education and general motivational treatment is provided to each participant. Afterwards, participants have to interpret a short video showing scenes of two different superhero movies together. Several questions ask about the characteristics of the two super heroes in the movie and whether these heroes are comparable. Both members of the dyad watch the movie together and answer the questions conjointly.
Education and motivation treatment
Adolescents will watch a movie from the Federal Office of Public Health Switzerland including the guidelines of physical activity (PA) for adolescents. All adolescents respond to a quiz afterwards. After the quiz, the experimenter repeats the guidelines for PA based on a brochure that all adolescents can take home with them. In addition, the experimenter asks for barriers and benefits of PA the adolescents perceive. Next to it, the experimenter explains that a weight gain might be possible due to PA in the beginning. Furthermore, the experimenter presents how the data of the accelerometer should look like if one is sufficiently physical active. As a last part self-efficacy as an important aspect of goal success is mentioned. The materials exclude any planning statements.
Interventions
Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.
Individual planning
Each participant forms up to three action and up to three coping plans individually, without consulting the participating friend, but discussing the plans with the experimenter. CONTENT: The planning materials and forms have the following sections: (a) information on the importance of planning (b) instructions of what should be included in a good plan (the when, where, and how components), (c) formulating action and coping plans based on the if-then structure. Action plans (referring to when, when, and how the individual will act) as well as coping plans (referring to how to overcome potential difficulties, risky situations or temptations to not engage in physical activity).
Collaborative planning
Both friends together create up to three if-then plans on when, where, and how both will implement PA together. In addition, up to three coping plans will be formed together. This jointly developed plan is discussed with the experimenter. CONTENT: The planning materials and forms have the following sections: (a) information on the importance of planning (b) instructions of what should be included in a good plan (the when, where, and how components), (c) formulating action and coping plans based on the if-then structure. Action plans refers to when, when, and how the individual will act) as well as coping plans (referring to how to overcome potential difficulties, risky situations or temptations to not engage in PA). All materials are formulated using the plural.
Education and motivation treatment
Adolescents will watch a movie from the Federal Office of Public Health Switzerland including the guidelines of physical activity (PA) for adolescents. All adolescents respond to a quiz afterwards. After the quiz, the experimenter repeats the guidelines for PA based on a brochure that all adolescents can take home with them. In addition, the experimenter asks for barriers and benefits of PA the adolescents perceive. Next to it, the experimenter explains that a weight gain might be possible due to PA in the beginning. Furthermore, the experimenter presents how the data of the accelerometer should look like if one is sufficiently physical active. As a last part self-efficacy as an important aspect of goal success is mentioned. The materials exclude any planning statements.
Eligibility Criteria
Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.
Inclusion Criteria
* Same sex of the adolescents of each friendship dyad
* Access to internet (smartphone or at home)
* Adolescents less active than 1 hour of moderate to vigorous physically active per day
* Adolescents with the intention to be more physically active
* Parental consent at the baseline for adolescents under the age of 16
* Adolescents consent at the baseline
Exclusion Criteria
* Romantic relationship with participating friend
* A BMI below 17
* Insufficient comprehension of the German language
* Pregnancy
* Participating in other intervention programmes targeting physical activity
14 Years
18 Years
ALL
Yes
Sponsors
Meet the organizations funding or collaborating on the study and learn about their roles.
Swiss National Science Foundation
OTHER
SWPS University of Social Sciences and Humanities
OTHER
University of Southern Queensland
OTHER
University of Zurich
OTHER
Responsible Party
Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.
Principal Investigators
Learn about the lead researchers overseeing the trial and their institutional affiliations.
Theda Radtke, PhD
Role: PRINCIPAL_INVESTIGATOR
University of Zurich
Locations
Explore where the study is taking place and check the recruitment status at each participating site.
University of Zurich
Zurich, Canton of Zurich, Switzerland
Countries
Review the countries where the study has at least one active or historical site.
Central Contacts
Reach out to these primary contacts for questions about participation or study logistics.
Facility Contacts
Find local site contact details for specific facilities participating in the trial.
References
Explore related publications, articles, or registry entries linked to this study.
Radtke T, Luszczynska A, Schenkel K, Biddle S, Scholz U. A cluster randomized controlled trial comparing the effectiveness of an individual planning intervention with collaborative planning in adolescent friendship dyads to enhance physical activity (TWOgether). BMC Public Health. 2018 Jul 24;18(1):911. doi: 10.1186/s12889-018-5818-6.
Related Links
Access external resources that provide additional context or updates about the study.
Information about physical activity
Other Identifiers
Review additional registry numbers or institutional identifiers associated with this trial.
100019_169781/1
Identifier Type: -
Identifier Source: org_study_id