shrek

I personally don't see any technical difficulties except sheer size of the (complicated) system. Why? It all has been done.

I and all my compatriots enjoy 'ownership' of personal medical data including all medical records; vaccination passport; all invoices to my insurer; logbook to see who, when, what and why have  accessed my health data (integrity provided with blockchain technology); all prescriptions and their history (we have only electronic prescription, no paper); organ-donor declaration of intent; managing  access to my medical data; access to all data about my children etc. Fun fact: for last 3 years my insurer has spent whopping 372 euros on my medical bills (while I paid for that ~15K euros insuarance tax); my medical records have been accessed 51 times (to enter, edit or look up information) in same period.

This system has enabled to detect fraudulant doctors/hospitals (for billing for healthcare not provided; writing prescription on your name used by other person etc) as anyone can see all records concerning themselves. Of course there are problems too but as general it's working as one can expect.