PPAs: fewer start-ups but better operations.
D003284:Contract Services; D003625:Data Collection; D006761:Hospitals; D006801:Humans; D007348:Insurance, Health / Q000639:trends*; D010067:Ownership; D010820:Physicians; D011243:Preferred Provider Organizations / Q000639:trends*; D014481:United States; D014600:Utilization Review