The Diet-Related Intra-Couple Dynamics Between Prostate Cancer Survivors and Their Partners Across the Prostate Cancer Trajectory

There are over 3.5 million prostate cancer (PCa) survivors in the United States, about one-third of whom develop comorbid conditions. Comorbidity is the leading cause of death for PCa survivors. A healthy diet protects survivors from comorbidities and improves PCa outcomes, yet few PCa survivors adhere to a healthy diet. Involving survivors and their families in dietary interventions promotes their collaborative engagement in healthy diets, improving the health outcomes for both. Yet no review has systematically synthesized such interventions. Thus, the first aim of this dissertation is to synthesize the current literature on dietary interventions that included both cancer survivors and their families or caregivers through a systematic literature review. Prostate cancer is often considered a “couple’s disease”; both survivors and their partners perceive the threat from PCa to their health and life, which may, in turn, increase their receptivity to adopting a healthy diet. One’s diet quality could be affected by both self-perceived and partner-perceived threat. The second aim of this dissertation is to examine the interdependent relationships between perceived threat and diet quality among PCa survivors and their partners by applying the Actor-Partner Interdependence Model in a secondary data analysis. The analysis uses data collected from 139 dyads in the control arm of a clinical trial (R01 NR016990, PI Song). Further, PCa survivors’ and their partners’ diets are influenced by neighborhood resources (e.g., food access). Thus, this secondary analysis also assessed how these dyadic relationships were moderated by neighborhood conditions, measured by area deprivation index (ADI).Furthermore, PCa survivors’ and their partners’ diets are affected by determinants within and beyond the survivor-partner dyad. Thus, the third aim is to identify the multilevel determinants that influence the diets of 18 PCa survivor and partner dyads through a qualitative descriptive study.Together, the three studies expand the literature regarding the determinants of diets both within the PCa survivor-partner dyad and from sources outside of the couple (e.g., other families and friends, community, and food policy). The findings inform effective strategies for couple-based, tailored dietary interventions. These strategies may be broadly applicable to other health behaviors and chronic illnesses.