More recently an attempt has been made to have a more simplified document. Dr. Barak Gastner from the University of Washington has published an Advance Directive for Dementia. This simplified 6 page document with instructions breaks down care decisions for mild, moderate or severe dementia.
In a more aggressive attempt, the question of fluid and nutrition is being addressed in New York State. This directive allows individuals, in advance, to ask that fluid and nutrition be withheld in advanced stages of dementia. This ADVANCE DIRECTIVE FOR RECEIVING ORAL FOODS AND FLUIDS IN THE EVENT OF DEMENTIA will no doubt be challenged in court cases. The Washington Post notes that even in states with death with dignity laws, withholding fluid and nutrition in dementia is not addressed. End of Life Choices New York has a press release explaining the rationale and drafting of the document.
As far as I know, there have been no published outcome studies in the utilization of these directives. Like all directives they have limitations: Will they be found? Will they be honored? Will aid workers be willing to deal with withholding fluid and nutrition in advance stages of dementia? How will the legal concerns be dealt with?