All except one of these studies found that a feeding tube did not prolong life for patients with advanced dementia. Most patients with feeding tubes do not survive very long. Several studies show that 20–30% of patients who get feeding tubes die within a month and 50–60% die within a year.ne of the therapies the decision maker may need to think about is whether the person with dementia would want a feeding tube. A feeding tube is a tube that goes through the skin and delivers food directly to the stomach.