Aim: To improve clinical and ethical understanding of patient preferences for information and involvement in decision making.Objectives: To develop and evaluate a clinical tool to elicit these preferences and to consider the ethical issues raised.Design: A before and after study.Setting: Three UK hospices.Participants: Patients with advanced life-threatening illnesses and their doctors.Intervention: Questionnaire on information and decision-making preferences.Main outcome measures: Patient-based outcome measures were satisfaction with the amount of information given, with the way information was given, with family or carer information, (...) and confidence about future decision making. Doctor-based outcome measures were confidence in matching information to patient preference, matching family or carer communication to patient preference, knowing patient preferences and matching future decision making with patient preference.Results: Of 336 admissions, 101 patients completed the study . Patient satisfaction with the way information was given and family communication improved after introduction of the tool. Doctor confidence improved across all outcome measures .Conclusions: Patient satisfaction and doctor confidence were improved by administering the questionnaire, but complex ethical issues were raised by implementing and applying this research. The balance of ethical considerations were changed by advanced life-threatening illness, because there is increased risk of harm through delivery of information discordant with the patient’s own preferences. The importance of truly understanding patient preferences towards the end of life is highlighted by this study. (shrink)