To determine patient characteristics associated with the desire for life-sustaining treatments in the event of terminal illness.In-person survey from October 1986 to June 1988.13 internal medicine and family practices in North Carolina.2,536 patients (46% of those eligible) aged 65 years and older who were continuing care patients of participating practices, enrolled in Medicare. The patients were slightly older than the 65+ general population, 61% female, and 69% white, and most had one or more chronic illnesses.The authors asked the patients whether they would want each of six different treatments (hospitalization, intensive care, cardiopulmonary resuscitation, surgery, artificial ventilation, or tube feeding) if they were to have a terminal illness. The authors combined responses into three categories ranging from the desire for more treatment to the desire for less treatment. After adjustment for other factors, 53% of women chose less treatment compared with 43% of men; 35% of blacks vs 15% of whites and 23% of the less well educated vs 15% of the better educated expressed the desire for more treatment. High depression scores also were associated with the desire for more treatment (26% for depressed vs 18% for others).Patients' choices for care in the event of terminal illness relate to an intricate set of demographic, educational, and cultural factors. These results should not be used as a shortcut to determine patient preferences for care, but may provide new insights into the basis for patients' preferences. In discussing choices for future life-sustaining care, physicians need to explore with each individual the basis for his or her choices.