Development and refinement of a complex intervention within cardiac rehabilitation services: experiences from the CADENCE feasibility study

Background: Patients who experience a cardiac event are at higher risk of developing depression than the general population. Despite this, cardiac rehabilitation (CR) programmes do not provide a systematic approach to psychological care for depression. The CADENCE study aimed to develop and pilot an enhanced psychological care (EPC) intervention consisting of behavioural activation (BA) and mental health care coordination. Following original research commissioning guidance, the intervention was planned to be embedded in routine care and delivered by CR nurses to patients with depression attending CR. This paper describes how qualitative methods were used to develop, embed and refine the intervention. Methods: This feasibility study involved three CR teams. Observations were made of CR nurses delivering usual care, of EPC training given to nurses, and of supervision sessions provided to the CR nurses. Four nurses were interviewed shortly after their EPC training, and three were interviewed again 6–7 months later having delivered EPC to patients. All nine patients recruited to receive EPC were interviewed. Analyses of the observation notes and interview transcripts focused on how the intervention could be improved in terms of its acceptability and implementation. Results: Variations were found between the CR teams regarding patient waiting list times, how CR was delivered, what facilities were available and how many CR sessions were offered to patients. EPC was acceptable to both nurses and patients. However, nurses struggled to provide this additional care within their existing workload and resources, and patients’ disrupted progression through the CR programme affected EPC delivery. Limited time and availability of private space meant nurses also delivered EPC by telephone, which was viewed as a pragmatic solution but less preferable than face-to-face. Nurses indicated that patients struggled with some of the written materials. Findings were used to revise the intervention to become a protocol of care coordination which included guided self-help BA. Conclusions: Insights gained through conducting interviews and observations enabled us to identify barriers to the implementation of EPC, and to modify the intervention to facilitate its delivery within existing services whilst remaining acceptable to both nurses and patients. The multiple method, iterative approach used was key to the success of this qualitative study.