Clinical trial NCT00142688: Examining Psychosocial Mediators of Exercise Behavior
Official title: Examining Psychosocial Mediators of Exercise Behavior
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE1
Conditions: Cardiovascular Diseases
Heart Diseases
Lead sponsor: HealthPartners Institute
Sponsor class: OTHER
Collaborators: name: National Heart, Lung, and Blood Institute (NHLBI)
First posted: 2005-09-02
Enrollment: 448
Sex: ALL
Maximum age (years): 100
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: The purpose of this study is to examine psychosocial mediators of exercise behavior.

Detailed description: BACKGROUND:

Physical inactivity is related to many health problems, including increased risk of cardiovascular disease, hypertension, and cancer. Despite the health consequences of a sedentary lifestyle, only 25 percent of Americans meet the recommended levels of physical activity. Researchers postulate that theory-based interventions effectively influence physical activity behavior by changing theoretical constructs believed to be important for behavior change (i.e., potential mediators), such as self-efficacy (i.e., confidence in one's ability to be physically active). Unfortunately, previous studies have generally failed to adequately test the mediating effect of theoretical constructs using appropriate statistical mediator analyses as recommended by leading behavioral scientists and statisticians.

DESIGN NARRATIVE:

The study will examine the mediating effect of theoretical constructs based on the Transtheoretical Model (TTM) and Social Cognitive Theory (SCT). The study will address the methodological, measurement, and statistical limitations of previous studies. The investigators will randomly assign 420 healthy sedentary individuals to either a theory-based physical activity intervention or a contact control group. Physical activity behavior and the potential mediators will be assessed monthly over 12 months. They hypothesize that constructs based on the TTM and SCT (i.e., behavioral processes, cognitive processes, self-efficacy, and decisional balance) will mediate the relationship between group assignment (intervention vs. contact control) and physical activity behavior, such that the effect of the intervention on physical activity behavior relative to the contact control group will be attenuated when controlling for the mediators. They will also examine the importance of particular mediators for different population groups (e.g., age, gender), which will help to create more effective interventions for these groups. Finally, they will conduct a cost analysis to not only inform policy makers of the cost of delivering the intervention within our study but also to estimate the cost of delivering each component of the intervention (i.e., mediator). The analysis will estimate the cost of future refined interventions that incorporate those active components that affect the mediators and physical activity in this study. In summary, the study will identify which mediators (i.e., theoretical constructs) are most effective for increasing physical activity, which will have an important public health impact given that this will likely lead to more efficacious and less costly interventions.

Eligibility criteria: Inclusion Criteria:

* In good health
* Living a sedentary lifestyle

Primary outcomes:
measure: Physical activity
timeFrame: Measured at baseline, 6, and 12 months
Secondary outcomes:
Other outcomes:
Locations:
city: Minneapolis
country: United States
facility: HealthPartners Research Foundation
state: Minnesota
Study officials:
affiliation: HealthPartners Institute
name: Beth A. Lewis, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Lewis BA, Williams DM, Martinson BC, Dunsiger S, Marcus BH. Healthy for life: a randomized trial examining physical activity outcomes and psychosocial mediators. Ann Behav Med. 2013 Apr;45(2):203-12. doi: 10.1007/s12160-012-9439-5.
citation: Lewis BA, Williams DM, Frayeh A, Marcus BH. Self-efficacy versus perceived enjoyment as predictors of physical activity behaviour. Psychol Health. 2016;31(4):456-69. doi: 10.1080/08870446.2015.1111372. Epub 2015 Nov 18.