Supporting data for "The effects of a dyadic psychosocial intervention on the mutuality, psychological and quality of life outcomes of patients with heart failure and their family caregivers: A mixed-methods study"

Heart failure (HF) is a debilitating and progressive condition that significantly affects patients and family caregivers, who often function as care partners and jointly navigate the illness trajectory. Within this partnership, their relational dynamics are pivotal in shaping how dyads cope with HF. However, existing dyadic interventions have given limited attention to optimising relational dynamics.This study aimed to develop and evaluate the effects of a relationship-focused dyadic psychosocial intervention, titled ‘Coping and Thriving Together (CTT)’, on the mutuality, psychological and quality of life (QoL) outcomes of patients with HF and their family caregivers. It was conducted in two phases to achieve this overall aim.Phase one comprised a qualitative evidence synthesis to enhance understanding of how dyads cope with HF together. Thirty articles were included in the synthesis. The findings revealed that dyadic coping in patients with HF and caregivers is a dynamic process of adopting constructive or destructive strategies to respond to the communal and intertwined challenges brought by the disease, shaped by the interplay of individual, relational and social conditions. The findings of this phase informed the development of the intervention in the phase two.Phase two employed a sequential mixed-methods design comprising a randomised controlled trial to evaluate the effects of the CTT intervention and a qualitative study to explore the dyadic experiences of participating in the intervention. HF dyads were recruited from a hospital in China. Eligible dyads (n = 152) were randomly assigned to either the intervention group (n = 76) to receive a 12-week CTT intervention on enhancing mutual responsiveness during dyadic adaptation to HF, or the control group (n = 76) to receive usual care. The mutuality, resilience, self-compassion, anxiety, depression and QoL outcomes of patients and caregivers were evaluated at baseline (T0), immediately post-intervention (T1), and three months thereafter (T2). Semi-structured interviews were conducted with 30 dyads from the intervention group.The findings indicated that compared with those in the control group, patient participants in the intervention group exhibited significantly greater improvements in mutuality and resilience at T1 and T2. They also experienced greater reductions in anxiety and depression at T1, with only the effect on depression remaining significant at T2. For caregivers, those in the intervention group reported significantly greater improvements in mutuality, self-compassion and QoL at T1 and T2, and significantly greater reductions in anxiety at T1. However, no between-group difference was found in patients’ self-compassion or health-related QoL nor in caregivers’ resilience or depression. Mediation analyses showed that patients’ perceived mutuality significantly mediated the intervention effects on patients’ depressive symptoms, whereas caregivers’ perceived mutuality and self-compassion significantly mediated the intervention effects on caregivers’ QoL. Qualitative findings revealed that patient and caregiver participants perceived better relational dynamics, enhanced disease management, improved emotional well-being, more adaptive mindsets and more constructive daily living patterns.The findings highlight that the CTT intervention effectively improves the relational and individual well-being of patients and caregivers. This study advances dyadic care models in HF, offering a promising approach for supporting dyadic adaptation to HF.