Illness uncertainty, coping, and quality of life in patients with advanced cancer and family caregivers: A dyadic study.

185 Background: Illness uncertainty is prevalent among patients with cancer and their family caregivers. While the relationship between illness uncertainty, coping, and quality of life (QOL) has been explored individually for patients or caregivers, it remains largely unexamined within patient-caregiver dyads. Guided by Mishel’s Uncertainty in Illness Theory, this study examined the relationships between illness uncertainty, coping, and QOL among patients with advanced cancer and family caregivers. Methods: This cross-sectional study analyzed the data from a randomized clinical trial that examined the effects of a dyadic-based intervention on psychological outcomes for patients with advanced cancer and family caregivers. Illness uncertainty, coping, and QOL were measured using the shorten version of the Mishel Uncertainty in Illness Scale for Adult, the Brief Cope, and the Functional Assessment of Cancer Therapy, respectively. The actor-partner interdependence mediation model was used to achieve the aim. Results: This study included 484 patient-caregiver dyads, with patients diagnosed with advanced breast (32.4%), lung (29.1%), colorectal (25.4%), and prostate cancer (13.0%). Patients’ avoidant coping mediated the relationship between their own illness uncertainty and QOL ( p < .001). Caregivers’ active coping and avoidant coping mediated the relationship between their own illness uncertainty and QOL ( p < .001). Notably, caregivers’ illness uncertainty was positively associated with patients’ avoidant coping ( b = 0.113; p < .01). Conclusions: This study is one of the first to use a dyadic approach to investigate the relationships between illness uncertainty, coping, and QOL in advanced cancer patients and caregivers. Our findings highlight the importance of viewing patient-caregiver dyads as the unit of care. These findings support targeted interventions offered to both patients and family caregivers to manage their illness uncertainty and improve their QOL. Giving the effect of caregivers’ uncertainty on patients’ coping, healthcare professionals should advocate for additional psychosocial supports for family caregivers. Clinical trial information: NCT00709176 .