Blockchain is often described as a solution in search for a problem. It’s a clever technology, but people don’t really know what it can be used for besides storing cryptocurrency transactions.
People have thought about storing other kinds of data in the blockchain, like health records, but no one can really point out to why this would be better than other solutions.
To achieve something similar with health records without blockchain, all that is needed is just a cryptographic signature. The hospital cryptographically signs a digital health document and email it to you. The hospital in turn stores it in some shared database accessible by other hospitals. Done.
If the health record is somehow lost from the shared database, then you got your own copy of it as backup. They can’t modify the health record either, because then it would diverge from your own copy.
The worst thing they can do is to add falsified health records without your approval, but that’s a problem with blockchain as well. Blockchain cannot verify that the input data is truthful (garbage in, garbage out).
The cryptographic signature step is a part of blockchain either way, so there’s no extra technical overhead in the non-blockchain way.