UC San Diego

Background: Younger breast cancer survivors (YBCS) consistently report poorer quality of life (QOL) than older survivors. One potential strategy to improve QOL is through increasing physical activity (PA), but this has been understudied in YBCS. YBCS face unique barriers to PA related to treatment side effects and life stage.

Purpose: This dissertation leveraged a community-academic partnership to evaluate the feasibility, acceptability, and implementation of a 3-month, peer-delivered, fully remote intervention to increase PA and improve QOL in YBCS.

Methods: Participants completed six video sessions with a trained YBCS peer mentor; self-monitored PA with a Fitbit activity tracker; and interacted with a private Fitbit Community for social support. At baseline, 3, and 6-months, participants completed validated QOL questionnaires and PA was measured through accelerometer (objective moderate-to-vigorous PA [MVPA]) and self-report (strength and flexibility). A parallel mixed methods approach (qualitative interviews and quantitative satisfaction survey) explored feasibility and acceptability. One-way repeated-measures ANOVA examined impacts on PA and QOL at 3-and 6-months. A multimethod process evaluation explored peer mentors’ barriers and facilitators to intervention delivery and adaptations.

Results: On average, participants (N=34) were 43.1±5.5 years old, 46±34.4 months post-diagnosis, and self-reported a BMI of 30.2±7.4 kg/m2. The intervention was feasible as evidenced by efficient recruitment, high retention, and adherence to intervention components. Remote delivery was highly acceptable, as were working with a peer mentor and using the suite of Fitbit tools to support behavior change. From baseline to 3-months, participants increased time spent in objectively-measured MVPA, strength, and flexibility exercises, and experienced meaningful improvements to QOL, including body image, fatigue, anxiety, and emotional support. Adaptations to enhance feasibility of study protocols and engagement in the Fitbit Community occurred throughout intervention delivery. Prominent barriers and facilitators to effective delivery were related to communication, preparation and training, complexity of technology, and life circumstances.

Conclusions: A fully remote, peer-to-peer, technology-based intervention is an acceptable and promising strategy to increase PA and improve QOL in YBCS. Refinements to the intervention and its implementation should be assessed in a fully-powered hybrid effectiveness-implementation trial, toward the goal of disseminating an evidence-based, scalable intervention to the growing number of YBCS.