One solution might be to create a small number of standard documents. Then trusted experts could certify a few (like the UL seal of approval on electronics), and people could just ask the receptionist if their document has such an endorsement.
Another would be to create a consumer protection law that prohibits doctors' offices from doing certain things even if patients explicitly signed those rights away.
I believe there are already standard documents, e.g. the huge binder the receptionist was referring to in the OP certified by a few "trusted experts", i.e. lawyers. The question is by whom are these experts trusted, which in practice means who employs them. How would people get a list of these experts (government intervention?)
Another would be to create a consumer protection law that prohibits doctors' offices from doing certain things even if patients explicitly signed those rights away.