Andreas Häusler, Alba Sánchez, Paul Gellert, Friederike Deeken, Johanna Nordheim, Michael Armin Rapp

• Background: Given the well-established association between perceived stress and quality of life (QoL) in dementia patients and their partners, our goal was to identify whether relationship quality and dyadic coping would operate as mediators between perceived stress and QoL. Methods: 82 dyads of dementia patients and their spousal caregivers were included in a cross-sectional assessment from a prospective study. QoL was assessed with the Quality of Life in Alzheimer's Disease scale (QoL-AD) for dementia patients and the WHO Quality of Life-BREF for spousal caregivers. Perceived stress was measured with the Perceived Stress Scale (PSS-14). Both partners were assessed with the Dyadic Coping Inventory (DCI). Analyses of correlation as well as regression models including mediator analyses were performed. Results: We found negative correlations between stress and QoL in both partners (QoL-AD: r = -0.62; p < 0.001; WHO-QOL Overall: r = -0.27; p = 0.02). Spousal caregivers had a significantly lower DCI total score than dementiaBackground: Given the well-established association between perceived stress and quality of life (QoL) in dementia patients and their partners, our goal was to identify whether relationship quality and dyadic coping would operate as mediators between perceived stress and QoL. Methods: 82 dyads of dementia patients and their spousal caregivers were included in a cross-sectional assessment from a prospective study. QoL was assessed with the Quality of Life in Alzheimer's Disease scale (QoL-AD) for dementia patients and the WHO Quality of Life-BREF for spousal caregivers. Perceived stress was measured with the Perceived Stress Scale (PSS-14). Both partners were assessed with the Dyadic Coping Inventory (DCI). Analyses of correlation as well as regression models including mediator analyses were performed. Results: We found negative correlations between stress and QoL in both partners (QoL-AD: r = -0.62; p < 0.001; WHO-QOL Overall: r = -0.27; p = 0.02). Spousal caregivers had a significantly lower DCI total score than dementia patients (p < 0.001). Dyadic coping was a significant mediator of the relationship between stress and QoL in spousal caregivers (z = 0.28; p = 0.02), but not in dementia patients. Likewise, relationship quality significantly mediated the relationship between stress and QoL in caregivers only (z = -2.41; p = 0.02). Conclusions: This study identified dyadic coping as a mediator on the relationship between stress and QoL in (caregiving) partners of dementia patients. In patients, however, we found a direct negative effect of stress on QoL. The findings suggest the importance of stress reducing and dyadic interventions for dementia patients and their partners, respectively.…