Supplementary Material for: Matters of Life and Death: An Experimental Study Investigating Psychological Interventions to Encourage the Readiness for End-of-Life Conversations

<b><i>Introduction:</i></b> Talking about death and dying is evoking discomfort in many persons, resulting in avoidance of this topic. However, end-of-life discussions can alleviate distress and uncertainties in both old and young adults, but only a minority uses this option in palliative care. Even in healthy populations, talking about death is often seen as alleviative and worthwhile, but rarely initiated. <b><i>Objective:</i></b> To investigate different psychological interventions (a) encouraging the readiness for end-of-life discussions and (b) changing death attitudes in healthy adults of different ages. <b><i>Methods:</i></b> 168 participants were randomized to four different interventions (IG1: value-based intervention with end-of-life perspective, IG2: motivation-based intervention with end-of-life perspective, IG3: combination of IG1 and IG2, CG: control group). Primary outcome was the readiness to engage in end-of-life topics. Secondary outcomes were fear of death, fear of dying and death acceptance. Assessments took place before, directly after the intervention and at 2 weeks of follow up. <b><i>Results:</i></b> IG2 and IG3 reported significantly more changes in the readiness to engage in end-of-life discussions than the CG (<i>F</i>[5.61, 307] = 4.83, <i>p</i> &lt; 0.001, η<i>p</i>² = 0.081) directly after the intervention. The effect of IG3 remained stable at the follow-up. There were no significant effects of the interventions on end-of-life fears or death acceptance. Acceptability of the interventions was very high. <b><i>Conclusions:</i></b> Short interventions can be useful to encourage end-of-life discussions and could be integrated in health care programs. The efficacy and effectiveness of these short interventions in palliative patients are currently examined.