Development and Psychometric Properties of PEACE-Q: A Questionnaire on Attitudes Towards Physician-Assisted Dying, Euthanasia, Advance Directives and Care at the End-of-Life.

Public attitudes toward euthanasia, physician-assisted dying (PAD), advance directives (ADs), and end-of-life (EOL) decision-making in the ICU remain underexplored, while existing tools address these issues fragmentarily. This study aimed to develop and psychometrically evaluate a novel, self-report instrument named Physician-assisted dying, Euthanasia, Advance directives and Care at the End-of-life Questionnaire (PEACE-Q) to cohesively assess relevant public attitudes. PEACE-Q was developed through literature review, expert evaluation and pilot testing, with initial validation conducted in Greece. Psychometric evaluation included exploratory factor analysis, item response theory modeling, internal consistency testing and test-retest reliability. Data were collected from 1,046 adults residing in Greece without additional eligibility criteria. Participation was voluntary, anonymous, and based on informed consent. Analysis yielded three reliable thematic sections on public perspectives: euthanasia/PAD with three subscales, ADs with two subscales, and EOL practices and palliative care with three subscales, all demonstrating excellent internal consistency and moderate intercorrelations. Additionally, the Existential Readiness and Death Acceptance Index (ERDAI) emerged as a composite score with excellent internal consistency (α = .911), reflecting preparedness towards EOL decision-making and death acceptance. PEACE-Q proved valid, reliable and conceptually cohesive for assessing attitudes on euthanasia, PAD, ADs, and EOL practices, applicable both independently per section and comprehensively through the ERDAI, with broad applicability across diverse cultural and legal settings.