If a declarant has become and remains incapacitated and has previously executed a valid advance directive under this chapter and executed:
if a material conflict exists between multiple documents described in this section or if a material conflict exists between the health care decisions that different health care representatives or other authorized agents propose to make under the multiple documents, or if there is a material difference between the documents, then the document signed last by the declarant and the authority of the named representatives or agents in that document controls.
IC 16-36-7-44