Dr. Marsha N. Wittink of the University of Pennsylvania School of Medicine in Philadelphia and her colleagues also found that aging or changes in study participants' mental and physical health had little influence on their treatment preferences.

Wittink and her colleagues looked at 1999 and 2003 survey results for 818 of the study's participants, who were asked whether or not they would want 10 different types of life-sustaining treatment if they had suffered permanent brain damage and were no longer able to speak or recognize people.

reuters.com