Don't you think advanced directives resulting in death should only be in WRITING????
And notarized.
A requirement that they be in writing would probably be struck down as being discriminatory against people who couldn't write. A requirement that advance directives be in authenticable tangible format would be better, but even that might have problems.
The SCoFla's ruling in Browning suggests that a statute which absolutely forbade oral declarations might very well be struck down as unconstitutional. Never mind that the the SCoFla has no right to legislate such things--they probably would do so anyway. Therefore, I would suggest that it might be good to have a statute which would allow for oral directives but only in cases where such allowance was necessary to avoid the wrath of the SCoFla judges.
Requiring that anyone who is capable of expressing an advance directive in tangible form must do so in order for such directive to be enforceable would not impose any unreasonable hardship on anyone. The tricky issue would be with those not capable of expressing their directive in tangible form. I would think criteria like the above should provide pretty good protection against falsified wishes while still allowing enough of a possibility of acknowledging oral ADs to satisfy the SCoFla. The language could perhaps use refinement, but I think the principles should be pretty solid.