Exploring pathways to optimise care in malignant bowel obstruction (EPOC): Protocol for a three-phase critical realist approach to theory-led intervention development for shared decision-making.

INTRODUCTION: Malignant bowel obstruction is a distressing complication of cancer, causing pain, nausea and vomiting, and often has a poor prognosis. Severe and rapidly developing symptoms, a lack of robust clinical guidelines and the need for multidisciplinary input make treatment decision-making challenging. Sharing decision-making with people with malignant bowel obstruction and their caregivers can be difficult, and inconsistent communication creates serious deficiencies in care by amplifying patients' distress and uncertainty. Little attention has been paid to the implicit influences on this process-for example, the role of discipline-related norms and the beliefs of decision-makers. This study will explore how these processes work and develop interventions to improve shared decision-making.

METHODS AND ANALYSIS: Exploring Pathways to Optimise Care (EPOC) is a three-phase study set within a critical realist framework: (i) realist review, to develop explanatory theory describing collaborative decision-making in the management of malignant bowel obstruction; (ii) an in-depth interview study using modified grounded theory to explore the active ingredients of this collaboration in practice settings; and (iii) the presentation to stakeholders (practitioners, patients and caregivers) of integrated results from Phase I (theory developed from the literature) and Phase II (theory developed from current practice) as a basis for intervention mapping. We aim to produce recommendations to address the challenges, and to develop a set of tools to (i) aid interaction around shared decision-making and (ii) aid interprofessional interaction around the management of this condition. Registration details: The realist review is registered with PROSPERO (CRD42022308251).