Context: Family members often lack the knowledge of patients' values and preferences needed to function well as surrogate decision-makers.
Objective: To determine whether differences in values and preferences for the advance care planning process may be reasons family members are inadequately informed to act as surrogates.
Design: Face-to-face and telephone surveys using structured questionnaires.
Participants: Two hundred forty-two pairs of dialysis patients and their designated surrogates.
Main outcome measures: Content and number of end-of-life care discussions; patient and surrogate attitudes toward having patients express preferences explicitly; factors most important to surrogates in decision making; and within-pair agreement about the values of suffering and certainty.
Results: Ninety percent of patients designated a family member as their surrogate. In most cases, having more conversations about end-of-life issues did not increase surrogate knowledge of patients' values or preferences. Surrogates wanted written and oral instructions more often than patients wanted to provide them (62% vs. 39%, p < 0.001). Knowing the patient's wish to stop treatment in the present condition was more important to most surrogates than the physician's recommendation to stop treatment (62% vs. 45%, p < 0.001). Compared to patients, surrogates were less likely to want to prolong the patient's life if it entailed suffering (12% vs. 23%, p < 0.01) and were more concerned about being certain before stopping life-sustaining treatments (85% vs. 77%, p < 0.02).
Conclusions: Differences in preferences for the advance care planning process between patients and their surrogates and failure to discuss specific end-of-life values and preferences may explain why surrogates often lack information needed to serve as surrogate decision-makers.