eFigure. Details of the questionnaire. Certain definitions were agreed on a priori for 2 of the survey questions. The first question asked to choose “stand-alone” reason(s) that “is/are an acceptable conceptual reason to explain why ‘brain death’ is equivalent to ‘death.’” For analysis, we classified responses into categories that have been discussed in the literature. A higher brain concept of brain death (BD) response was considered any of irreversible loss of consciousness, irreversible loss of the soul or “the essence” of man, or irreversible loss of “personhood.” A prognosis concept of BD response was considered any of the certainty of cardiac arrest within hours or days or further care is futile and/or degrading. A statement of loss of brain function response (this is the criterion, and not a concept, to justify why this loss of brain function was death) was considered any of irreversible loss of the function of the entire brain, including the brainstem, or irreversible loss of the critical functions of the entire brain, including the brainstem. Similarly, the seventh question asked “This patient fulfills all brain death criteria unequivocally, including the suitable interval. Conceptually, why are they dead (ie, in your own words, what is it about loss of brain function including the brainstem that makes this patient dead)?” We planned to divide responses into the same categories as previously described. After reviewing the returned surveys, the following was used to categorize the narrative responses. A higher brain concept of BD was considered any mention of consciousness, ability to interact, personhood, the soul, the self, or “a unique individual.” A loss of integration of body concept of BD was considered any mention of ability to breathe, maintain homeostasis, or maintain integration. A quality-of-life statement was considered any mention of quality of life or “reasonable survival.” A prognosis of death being certain statement was considered any mention of inevitable cardiac arrest, “the patient will die soon,” or “maintaining life on machines.” The quality-of-life and prognosis of death statements were combined as the prognosis concept of BD. Any response that stated only that the brain has died, the patient fulfills the BD criteria, there is no brain function, or BD is an accepted standard was considered a statement (of “fact”) only (the criterion, and not a concept, to justify why this loss of brain function was death). EEG indicates electroencephalogram; TSH, thyrotropin.