Patient values and preferences for end-of-life treatments: are values better predictors than a living will?

BACKGROUND: Advance care planning is widely considered important for good treatment decision making. Patient values have been proposed as superior to standard living wills as guides to end-of-life (EOL) care decisions on behalf of decisionally incapacitated patients. Little research has examined whether values outperform living wills as predictors of treatment preferences.
OBJECTIVE: The study aimed to test whether patient values are associated with treatment preferences, compare values and preferences to responses from a standard living will, and determine whether some values are better predictors than others.
DESIGN: Community-dwelling elderly men and women (n=304) were interviewed in their homes by telephone. The interview consisted of an eight-item EOL values scale, a standard living will question, preferences for four life-prolonging treatments in each of six scenarios, and sociodemographic questions.
RESULTS: Principal components analysis of the EOL values revealed two factors: (1) dignity, pain management, and reluctance to burden others; and (2) religiosity and desire for longevity and following family wishes. In regression analyses, stronger preferences for life-prolonging treatments were correlated with higher scores on factor 1 and lower scores on factor 2. But when living will responses were also entered into the regression model, only religiosity, longevity, and following family wishes predicted treatment preferences independently of the living will responses.
CONCLUSIONS: Providing better guidance than a living will in determining a patient's EOL treatment preferences are (1) knowledge about a patient's religiosity, (2) patient's wishes for longevity, and (3) patient's wishes for following family preferences. Wishes for dignity and pain management and reluctance to burden others do not offer better guidance than a living will.