Managed care. Even higher cost can't turn employers away from PPOs.
D003625:Data Collection; D018588:Fee-for-Service Plans / Q000706:statistics & numerical data; D019981:Health Care Sector / Q000706:statistics & numerical data; D006279:Health Maintenance Organizations / Q000706:statistics & numerical data; D011243:Preferred Provider Organizations / Q000706:statistics & numerical data*; D014481:United States