PEGASUS: the Design of an Intervention to Facilitate Shared Decision-making in Breast Reconstruction.

Studies have found varying levels of satisfaction after breast reconstruction surgery with a substantial group of patients reporting some level of regret about their decision. The variable outcomes reported by women undergoing breast reconstruction surgery suggest a role for improved pre-operative communication and shared decision-making (SDM) between patient and health professional. Pragmatic approaches such as decision aids have been evaluated, but the aim of the Patient Expectations and Goals Assisting Shared Understanding of Surgery (PEGASUS) intervention is to facilitate closer interaction between the patient and clinical team. PEGASUS is a standardised two-stage process, in which patients' goals are first elicited, ranked in importance and recorded before being used to frame discussion and decision-making with the surgeon managing care. Following the Medical Research Council (MRC) model, feasibility and acceptability studies have already been reported and a 4-year multicentre randomised controlled trial of 180 participants is underway, (completion 2020). This paper therefore focuses on the design of the intervention itself, in line with recent advice that interventions, in comparison with evaluations, commonly lack a theoretical base and are often under reported. We report a retrospective application of the Capability, Opportunity, Motivation-Behaviour (COM-B) model to provide explicit detail of each step in the intervention design. This is intended to facilitate replication by other clinicians and to provide systematic guidance for others wishing to develop PEGASUS as a strategy for implementing SDM in other clinical populations. Trial Registration: ISRCTN 18000391 (DOI 10.1186/ISRCTN18000391) 27/01/2016.