Background: The questions patients are asked about their preferences with regard to life-sustaining treatment usually focus on specific interventions, but the outcomes of treatment and their likelihood affect patients' preferences.
Methods: We administered a questionnaire about treatment preferences to 226 persons who were 60 years of age or older and who had a limited life expectancy due to cancer, congestive heart failure, or chronic obstructive pulmonary disease. The study participants were asked whether they would want to receive a given treatment, first when the outcome was known with certainty and then with different likelihoods of an adverse outcome. The outcome without treatment was specified as death from the underlying disease.
Results: The burden of treatment (i.e., the length of the hospital stay, extent of testing, and invasiveness of interventions), the outcome, and the likelihood of the outcome all influenced treatment preferences. For a low-burden treatment with the restoration of current health, 98.7 percent of participants said they would choose to receive the treatment (rather than not receive it and die), but 11.2 percent of these participants would not choose the treatment if it had a high burden. If the outcome was survival but with severe functional impairment or cognitive impairment, 74.4 percent and 88.8 percent of these participants, respectively, would not choose treatment. The number of participants who said they would choose treatment declined as the likelihood of an adverse outcome increased, with fewer participants choosing treatment when the possible outcome was functional or cognitive impairment than when it was death. Preferences did not differ according to the primary diagnosis.
Conclusions: Advance care planning should take into account patients' attitudes toward the burden of treatment, the possible outcomes, and their likelihood. The likelihood of adverse functional and cognitive outcomes of treatment requires explicit consideration.