OBJECTIVES: This study was designed to identify and compare the attitudes of patients and health care professionals towards advance directives. Advance directives promote recognition of the patient's autonomy, letting the individual exercise a certain measure of control over life-sustaining care and treatment in the eventuality of becoming incompetent. DESIGN: Attitudes to advance directives were evaluated using a 44-item self-reported questionnaire. It yields an overall score as well as five factor scores: autonomy, beneficence, justice, external norms, and the affective dimension. SETTING: (...) Health care institutions in the province of Québec, Canada. Survey sample: The sampling consisted of 921 subjects: 123 patients, 167 physicians, 340 nurses and 291 administrators of health care institutions. RESULTS: Although the general attitude of each population was favourable to the expression of autonomy, multivariate analysis of variance (MANOVA) indicated that physicians attached less importance to this subscale than did other populations (p < .001). Above all, they favoured legal external norms and beneficence. Physicians and administrators also attached less importance to the affective dimension than did patients and nurses. Specifically, physicians' attitudes towards advance directives were shown to be less positive than patients' attitudes. CONCLUSION: More attention should be given to the importance of adequately informing patients about advance directives because they may not represent an adequate means for patients to assert their autonomy. (shrink)