Condition category
Nutritional, Metabolic, Endocrine
Date applied
20/03/2012
Date assigned
27/04/2012
Last edited
02/08/2016
Prospective/Retrospective
Retrospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Regular physical activity has a positive impact on health in general and on weight in particular. However, 60% of the Swiss population do not regularly take part in physical activity and 37% are overweight or obese. The aim of this study is to examine the benefits ofphysical activity in overweight and obese couples, specifically the role of the partner in increasing physical activity.

Who can participate?
Overweight or obese, heterosexual adult couples want to increase their physical activity

What does the study involve?
Participating couples, with one partner being the target person, are randomly allocated to one of four different groups. At the start of the study, participants in all four groups receive an information leaflet on the benefits of physical activity for health and weight management. Additionally, target people and their partners in group 1 are instructed to set behavioral goals on how to increase the target person’s physical activity to the recommended level. The target people in group 2 are instructed to set behavioral goals on their own. During the following two weeks, target people receive a daily text message reminding them of their goals. In group 1 the text-message reminder is sent by the partner, and in group 2 it is sent by the study personnel. Participants in groups 3 and 4, as well as the partners of group 1 and 2, also receive reminders to complete their daily diary. Participants in group 3 are instructed to not set any behavioral goals. Participants in group 4 complete a diary without reporting their physical activity.

What are the possible benefits and risks of participating?
Completion of the study is reimbursed with CHF 200 per couple. Furthermore, participants of all four groups may increase their level of physical activity. In none of the four groups will participants encounter any risks, inconveniences or disadvantages.

Where is the study run from?
University of Bern (Switzerland)

When is the study starting and how long is it expected to run for?
March 2012 to January 2014

Who is funding the study?
Swiss National Science Foundation (Switzerland)

Who is the main contact?
Ms Corina Berli
corina.berli@psy.unibe.ch

Trial website

http://www.ges.psy.unibe.ch/aktiv/

Contact information

Type

Scientific

Primary contact

Prof Urte Scholz

ORCID ID

Contact details

University of Konstanz
Department of Psychology
PO Box 5560
Box 14
Konstanz
78457
Germany

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

N/A

Study information

Scientific title

Individual versus dyadic action control: a randomized controlled trial to promote physical activity in overweight and obese couples

Acronym

DYACTIC

Study hypothesis

1. Is a dyadic action-control intervention more effective in promoting physical activity than an individual action-control intervention and control conditions? Is the effect of dyadic action-control dependent on the individual regulation capacities?
It is assumed that the dyadic action control intervention is superior in its effects on physical activity in an intentional sample than an individual action control intervention or control conditions. Both experimental groups (dyadic vs. individual action control) should be more successful in their behavioral change than control conditions. Moreover, it is assumed that this positive effect of dyadic action control is even more pronounced in individuals low in their individual self-regulation competencies.

2. What are the meditating mechanisms of the dyadic and individual action control conditions?
It is hypothesized that in the individual action control condition, the potential mediating mechanisms are enhanced action control and self-efficacy. The mediating mechanisms in the dyadic action control condition are in addition to these two individual components also social control and social support.

3. Are there gender differences in the effectiveness of a dyadic action control intervention?
It is assumed that men benefit more from a dyadic action control intervention provided by their heterosexual partner than women.

Ethics approval

Faculty of Human Sciences Ethics Committee, University of Bern, 21/02/2012 ref: 2011-12-36206

Study design

Single-blind single-centre randomized controlled trial with longitudinal design

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Trial setting

Other

Trial type

Quality of life

Patient information sheet

http://www.ges.psy.unibe.ch/aktiv/ [German]

Condition

Physical activity in overweight and obese individuals

Intervention

Experimental group I: Dyadic action-control group
1. Information leaflet on the benefits of moderate-intensity physical activity and the recommendations of the Swiss Federal Office of Sports (BASPO).
2. At the end of the baseline session, target persons and their partners are instructed to form behavioral goals to increase the target person’s physical activity to the recommended levels (e.g., “get off the bus two stops earlier when going to work” or “take the bike instead of the car”).
3. Partners are instructed to send daily text messages aiming at reminding the target person to their physical activity goals in personalized form (e.g., “Dear Peter, which of the planned activities have you already carried out today? Love, Regula”) on weekdays during the two weeks following baseline assessment. Target persons will not be informed that partners will receive a reminder text message from the study personnel every day instructing them to send the text message (and to fill in the diary at the end of the day).

Experimental group II: Individual action-control group
1.Information leaflet on the benefits of moderate-intensity physical activity and the recommendations of the Swiss Federal Office of Sports (BASPO).
2. At the end of the baseline session, target persons alone are instructed to form behavioral goals to increase their physical activity to the recommended levels (e.g., “get off the bus two stops earlier when going to work” or “take the bike instead of the car”).
3. On weekdays during the two weeks following baseline assessment, the target persons will receive a daily text messages from the study personnel aiming at reminding the target person to their physical activity goals. Partners of the target persons in this condition will receive a text message at the same time with the prompt to complete the diary at the end of the day.

Control group I: Full diary version
1. Information leaflet on the benefits of moderate-intensity physical activity and the recommendations of the Swiss Federal Office of Sports (BASPO).
2. Couples in control group I will not be instructed to form any behavioral goals, but will also receive text messages (at the same time as all other participants) with the prompt to complete the diary at the end of the day.

Control group II: Diary without self-reported physical activity
1. Information leaflet on the benefits of moderate-intensity physical activity and the recommendations of the Swiss Federal Office of Sports (BASPO).
2. Couples of this second control group will receive the same instructions and text messages during the diary phase as control group I participants. As completing a diary on self-reported physical activity might in itself trigger self-monitoring, albeit not as strongly as the two intervention groups, the second control group serves the purpose to control for this potential diary effect by only completing questions on social-cognitive variables, but not on self-reported physical activity. Thus, this group will rely on ambulatory momentary monitoring of physical activity by means of an accelerometry only.

Intervention type

Behavioural

Phase

Drug names

Primary outcome measures

1. 7-day-recall of physical activity, measured using an adapted version of the Physical Activity Frequency Questionnaire (PAFQ; Bernstein et al., 1998) and German-PAQ-50+ (Huy & Schneider, 2008) at baseline, 1 month follow-up and 6 month follow-up.
2. 24-hour-recall of physical activity, measured using an adapted short version of the Physical Activity Frequency Questionnaire (PAFQ; Bernstein et al., 1998) during the diary phases, i.e., daily during 28 days following baseline assessment and daily during 14 days after 6 month follow-up.
3. Accelerometry Data of physical activity (amount of light, moderate and intense activity per day, energy expenditure per day), measured by Actigraph devices GT3X+ daily during 28 days following baseline and daily during 14 days after 6 month follow-up.

Secondary outcome measures

1. Habitual physical activity, measured using the Baecke Index at run-in period and 6 month follow-up
2. Body Mass Index (BMI), waist circumference, waist-to-hip-ratio, measured at baseline, one month follow-up and 6 month follow-up
3. Aerobic fitness, measured by the submaximal cycle test Aerobic Power Index at baseline and 6 month follow-up.

Overall trial start date

16/03/2012

Overall trial end date

03/01/2014

Reason abandoned

Eligibility

Participant inclusion criteria

1. Heterosexual adult couples
2. Being committed for at least 12 months
3. Cohabitating for at least 6 months
4. German-speaking
5. BMI > 25
6. Physically inactive and intending to be more active

Participant type

Healthy volunteer

Age group

Adult

Gender

Both

Target number of participants

160 couples (n=40 couples per group)

Participant exclusion criteria

1. 24-hour shift work
2. Pregnancy

Recruitment start date

16/03/2012

Recruitment end date

03/01/2014

Locations

Countries of recruitment

Switzerland

Trial participating centre

University of Konstanz
Konstanz
78457
Germany

Sponsor information

Organisation

University of Bern (Switzerland)

Sponsor details

Institute of Psychology
Health Psychology
Alpeneggstrasse 22
Bern
3012
Switzerland

Sponsor type

University/education

Website

http://www.ges.psy.unibe.ch

Funders

Funder type

Research organisation

Funder name

Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung ref: PP00P1_133632/1

Alternative name(s)

Swiss National Science Foundation, Fonds National Suisse de la Recherche Scientifique, Fondo Nazionale Svizzero per la Ricerca Scientifica, Fonds National Suisse, Fondo Nazionale Svizzero, Schweizerischer Nationalfonds, SNF

Funding Body Type

private sector organisation

Funding Body Subtype

foundation

Location

Switzerland

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/25540972
2016 results in: http://www.ncbi.nlm.nih.gov/pubmed/27421075

Publication citations

Additional files

Editorial Notes

02/08/2016: Plain English summary added. 18/07/2016: Publication reference added.