The changing role model, and the shift in power.
D049672:History, 19th Century; D049673:History, 20th Century; D006801:Humans; D008505:Medical Staff, Hospital / Q000458:organization & administration*; D008486:Physician Executives / Q000266:history*; D010819:Physician's Role; D011057:Politics; D012380:Role; D014481:United States