Blockchain will never have a significant impact on HIT; in the short-run, it will be a boost to conferences, consultants, and marketing. In the long-run it will be utilized but won't have any material impact.
We do not need yet another niche domain security control. Instead, what we desperately need is a ubiquitous one. Blockchain is a contender for that. We need to determine who will pay for it. Nominally, the beneficiaries will pay through some proxy rather than taxpayer funding.
The boundary between what is health data and what isn't is shifting and porous. Any security technology that draws a bright line border will soon become obsolete. On the other hand, security technology that straddles or ignores the boundary has a greater and continuing return on investment.