I would advise you to look up Medrec when the use case is related to health care. Most of the research is geared towards dealing with keeping the data off the chain. In addition, there are other blockchains that might provide a better solution, for more privacy, for example, I would look up quorum by JP Morgan. There are different formats being looked at but these can give you two possible solutions. Also, check out Health Nexus' whitepaper, it deals with medical blockchain technology. Let me know if you need more.
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