Implementation of a frailty intervention in the transition from hospital to home: a realist process evaluation protocol for the FORTRESS trial

INTRODUCTION: Frailty in Older people: Rehabilitation, Treatment, Research Examining Separate Settings (the FORTRESS study) is a multisite, hybrid type II, stepped wedge, cluster, randomised trial examining the uptake and outcomes of a frailty intervention. The intervention is based on the 2017 Asia Pacific Clinical Practice Guidelines for the Management of Frailty and begins in the acute hospital setting and transitions to the community. The success of the intervention will require individual and organisational behaviour change within a dynamic health system. This process evaluation will examine the multiple variables at play in the context and mechanism of the frailty intervention to enhance understanding of the outcomes of the FORTRESS study and how the outcomes can be translated from the trial into broader practice. METHODS AND ANALYSIS: The FORTRESS intervention will recruit participants from six wards in New South Wales and South Australia, Australia. Participants of the process evaluation will include trial investigators, ward-based clinicians, FORTRESS implementation clinicians, general practitioners and FORTRESS participants. The process evaluation has been designed using realist methodology and will occur in parallel to the FORTRESS trial. A mixed-method approach will be used with qualitative and quantitative data collected from interviews, questionnaires, checklists and outcome assessments. Qualitative and quantitative data will be examined for CMOCs (Context, Mechanism, Outcome Configurations) and programme theories will be developed, tested and refined. This will facilitate development of more generalisable theories to inform translation of frailty intervention within complex healthcare systems. ETHICS AND DISSEMINATION: Ethical approval for the FORTRESS trial, inclusive of the process evaluation, has been obtained from the Northern Sydney Local Health District Human Research Ethics Committees reference number 2020/ETH01057. Recruitment for the FORTRESS trial uses opt-out consent. Dissemination will be via publications, conferences and social media. TRIAL REGISTRATION NUMBER: ACTRN12620000760976p (FORTRESS trial).