Steve,
At least in the US, each group overseer is currently tasked with getting a copy of everyone's filled out DPA (not really a DPA....but you know).
So until he can cross this little item of his list, people get reminded often.
I have a friend who is not filling out his card, but is still an active JW. His overseer sends weekly e mails or reminders to put it together. He just ignores them. He currently does not have all of his privileges, and my guess is that those would not come as long as this thing hasn't been checked off.
We discussed his potential response to them should they press. Here is what we came up with.
"I have family in the medical field, and there is a great deal that can go wrong with even basic medical information in the hands of people I may not necessarily know very well or trust in certain cases. I'm comfortable handling this on my own and without intervention from the brothers, but thanks for the willingness. Oh and you guys might want to study up on the local laws....HIPPA regulations are in effect when you are storing medical directives, and there could be several ways you guys might be in violation of those regulations."