I can second the testimony about lots of upheaval and consolidation in the industry. A family member recently worked at a Big Law firm on antitrust cases, and a large portion of them had to do when recent M&A activity among hospitals, specialty clinics, and small practices. The days of the doctor as small-business proprietor are waning.
One interesting aspect with the consolidation of hospitals is that they are generally buying smaller hospitals, it isn't some massive merger which gives them immunity from anti-trust cases.