This is especially true for Health Records with regards to US Health Care, as access control is heavily monitored and Hospital Employees are instructed clearly and frequently that you do not access records for anyone you are not treating, accidental access needing to be reported, and so on. Confidentiality of the patient records requires a clear system to see who accessed what, when, and from where they accessed it.
Blockchain seems like a complete mismatch for such an endeavor.
Just because a node can participate in a blockchain and cryptographically verify the chain doesn't mean the node can access the plaintext of every record in check chain.
Check out permissioned implementations like JP Morgan's Quorum.
Blockchain seems like a complete mismatch for such an endeavor.