It’s not going to be easy. Health care has had a hard time agreeing to things like ICD-10 or HL7, much less interoperability standards.
Getting on the Blockchain Bandwagon
Kim Bellard

You are correct about this problem — but this is 10X harder for blockchains because they require voluntary agreement by competing commercial interests — that are designed to increase their legal liability and decrease their revenue. Good luck selling that into healthcare.