Here are my views on blockchain in health data:
The blockchain is being applied in the healthcare industry. The physical records of health are going digital one step at a time. Previously, documents like Xrays and CT scan are now available in digital formats which are flexible for hospitals and research. But, this possesses the threat to both consumer records as now they are in digital form they can be modified. Not just this, but the insurance price in many cases dependent on the health condition. In this case, health data is becoming more important even in day to day life. In this situation, we need some technology that can store the data and records safety and validate them. This gives users data protection as data is not distributed. And as other blockchain techs, it is write only so the data is safe. I feel all future healthcare documents including tests, medication should be stored in the blockchain. As always the protection of data would be a concern even though it is a restricted ledger but by gaining access to one ledger entire data can be accessed.
References: http://www.theverge.com/2017/3/10/14880094/deepmind-health-uk-data-blockchain-audit