Abstract
BACKGROUND: The challenges of advanced cancer have health implications for patients and their family caregivers from diagnosis through end of life. The nature of the patient/caregiver experience suggests that their mental and physical health maybe interdependent, but limited empirical evidence exists. PURPOSE: This study used social cognitive theory as a framework to investigate individual and interpersonal influences on patients' and their family caregivers' mental health, physical health, and self-efficacy as individuals to manage the challenges of advanced disease over time. METHODS: Patients and caregivers (484 patient-caregiver dyads) completed surveys at baseline, 3 and 6 months. Longitudinal dyadic analysis techniques were used to examine (i)the influence that patients and caregivers had on their own mental health, physical health, and self-efficacy (actor effects)and (ii) the influence that they had on each other's health outcomes (partner effects). We also examined the influence of self-efficacy on mental and physical health over time. RESULTS: Consistent with our hypotheses, each person's mental health, physical health, and self-efficacy had significant effects on their own outcomes over time (actor effects). Patients and caregivers influenced one another's mental and physical health (partner effects), but not their self-efficacy. In addition, patients and caregivers with higher self-efficacy had better mental health, and their partners had better physical health. CONCLUSIONS: Patients' and caregivers' mental and physical health were interdependent. Each person's cancer-related self-efficacy influenced their own mental and physical health. However, a person's self-efficacy did not influence the other person's self-efficacy.