Discussing the evolution of life-threatening diseases and end-of-life issues remains difficult for patients, relatives and professionals. Helping people discuss and formalise their preferences in end-of-life care, as planned in the Go Wish intervention, could reduce health-related anxiety in the advance care planning (ACP) and advance directive (AD) process. The aims of this study are (1) to test the effectiveness of the Go Wish intervention among outpatients in early-stage palliative care and (2) to understand the role of defence mechanisms in end-of-life discussions among nurses, patients and relatives.