I'm a PhD from Bio background who became a data-scientist in a health-care related (but not biology research) company. I have been reasonably successful in this job, but because of the change in fields I lost my H1B to a failed RFE the one time I passed the lottery. Now I'm thinking of doing an O1 application, but my assumption has been that all my expertise must now be demonstrated in this new field of health-care data analytics and not from my PhD times, and I'm working on it.

My question is, has the difficulty of getting O-1 visas gone up significantly in the past year or so?