In the United States. the three largest such firms are HCA, Tenet (formerly NME), and HealthSouth. HealthSouth, as the third-largest U.S. national chain, is also the leading provider of rehabilitation services.
Advocates of such institutions claim they are able to provide better care at lower cost due to higher efficiency.
Detractors, however, claim that the relative success of for-profit medical providers arises from their positioning themselves in the medical marketplace in such a manner as to offer mainly profitable care services for a largely affluent and insured clientele whilst avoiding unprofitable care areas. Critics thus claim, for example, that for-profit hospitals specialize in such highly lucrative fields as medical rehabilitation, elective/plastic surgery, and cardiology while avoiding provision of loss-making services such as emergency medicine which in turn caters mainly to the indigent. Analogously, critics of for-profit HMOs argue that such firms disproportionately insure healthy people, while simultaneously eschewing chronically ill patients, who must then by default be cared for disproportionately by public insurance schemes and non-profit providers--thus a so-called "dumping" of undesirable patients.
They have also been criticised by elements of the Canadian medical establishment as providing inferior care at higher cost. See this commentary in the Canadian Medical Association Journal and this editorial in the New England Journal of Medicine.