Pilot Trial of Physical Activity Partnerships for Women in Midlife with Elevated Risk for Cardiovascular Disease - ABSTRACT During midlife (ages 40-65), women experience changes that escalate their risk for cardiovascular disease (CVD). Regular physical activity (PA) protects women against CVD risk, particularly among those with risk factors such as hypertension and obesity. Yet, despite the wide range of behavioral PA promotion programs designed for this population, women show insufficient PA during midlife. A key barrier is lack of adequate social support for PA, which is crucial to women’s successful adoption and maintenance of PA. Forming PA partnerships between program participants (i.e., women with no pre-existing relationship to one another) is a promising approach to meet this need. Our team’s preliminary data show the feasibility, acceptability, and potential impact of a partner-based approach to promote PA among women in midlife with elevated CVD risk. Critically, however, several key features of this approach require additional testing: (1) effective procedures for recruiting, randomizing, and retaining women in a PA promotion trial that includes both individual PA coaching and PA coaching+partner arms, (2) efficient and scalable procedures for pairing PA partners who are matched on specific characteristics, and (3) an acceptable solution to the challenge of withdrawal or disengagement on the part of one partner. Refining and finalizing these elements are essential to rigorously testing the efficacy and mechanisms of partner-based PA intervention for women in midlife with elevated CVD risk. To achieve these goals, we will conduct a pilot trial that uses intensive ambulatory assessment throughout a 12-week PA skills coaching program. Participants will be N=160 insufficiently active women ages 40-65 with >1 CVD risk factors who complete brief daily assessments; this approach allows us to track PA progress, partner communication, and potential mechanisms of action as they unfold in daily life. At the start of treatment, participants will be randomized with 3:1 allocation to receive PA coaching+partner (i.e., another woman who enrolls at the same time; n=120, experimental) or individual PA coaching (n=40, control) and complete 12 weeks of intervention. At mid-treatment (6 weeks), those in the coaching+partner condition whose partners withdraw or show poor engagement will be re-randomized to (a) individual coaching, (b) coaching+new partner, or (c) self-selection from these options, for the second half of treatment. This will enable us to experimentally test the best path for retaining, engaging, and promoting PA with women who lose partners during the intervention. We will achieve three specific aims: to confirm the feasibility, acceptability, and integrity of a randomized trial protocol involving individual versus partner-based PA coaching (Aim 1), to define optimal procedures for partner matching and re-formation (Aim 2), and to finalize the protocol for a future trial (Aim 3). Achieving these aims will inform the final protocol for a rigorous, fully powered clinical trial testing the efficacy, mechanisms, and moderators of PA partnerships for women in midlife with elevated risk for CVD.
