Stability of elderly persons' expressed preferences regarding the use of life-sustaining treatments.

The purpose of the study was to assess the stability of expressed preferences for the use of life-sustaining treatments (LST) in severe illness conditions over two years. The two year longitudinal study included three structured interviews with a one-year interval (1994, 1995, and 1996). At baseline, 1138 Israeli elderly persons (70+) were interviewed, 802 and 638 were interviewed in the following stages. Stability over time was assessed on the basis of score differences on two different indices that measured the wish to prolong life. Overall 70% of the respondents had stable preferences for the use of LST over time. This result was similar on both indices. The large majority of those with stable preferences (86%) did not want to prolong life already in the baseline interview. This was the most stable group. Among those who changed their wishes, the group that wanted LST less at stage 3 (20%) was twice as large as the group that wanted LST more (10%). These findings, which are similar to those reported in a study of an American sample, indicate a high level of stability in elderly persons' expressed preferences for LST at the end of life, and, therefore, strengthen the ethical basis for using advance directives. They also indicate that elderly persons of different cultural backgrounds may face similar problems regarding the prolongation of life and respond to them similarly.