Baseline assessments
In-person baseline assessments and subsequent access by researchers to clinical and administrative records enabled gathering of comprehensive information (Additional file Trial schemaThe research team cross-checked a 10% sample of data entries for accuracy and completeness. The Patient Experience with Treatment and Self-Management (PETS) questionnaire [At 6- and 9-month follow-up, the research team will make repeated attempts to re-engage patients, as will the PHOENIx team during the intervention phase.Descriptive outcomes will be conducted by independent statisticians after collection of 9-month follow-up data, using MINITAB statistical software (version 21) [An embedded economic evaluation will examine the feasibility of determining the cost-effectiveness of the PHOENIx intervention in a subsequent definitive trial. The main analysis will consider a health and social care service perspective whereby unit costs are applied to each item of health (e.g. hospitalisation) and social care service use data. Unit costs will be taken from routine sources where possible including missed appointments [Qualitative components are embedded in this study, to enable an understanding of how participants respond to the intervention alongside an exploration of the contextual issues in which the RCT occurs [