Public discussion has raised more questions over the last few months about physicians taking care of patients as corporate employees. 
More Physician Practices Taken over by Large CorporationsThis year, more stories have appeared about large corporations taking over physician practices.  In February, there was an account of efforts by competing nominally non-profit health insurance company Highmark and nominally non-profit hospital system UPMC in Pittsburgh in a "race to gobble up private physician practices," 
per the Pittsburgh Tribune-Review.  In March, the Washington Post 
featured a first-person account of what it is like for a physician in a private practice to try to hold out against the trend towards corporate practice.  In May, the Los Angeles Times
 noted how for-profit dialysis provider Da Vita purchased a large, but already for-profit operator of physician groups.  In October, Reuters 
reported how the recently announced acquisition by giant for-profit insurance company UnitedHealth of the biggest Brazilian for-profit managed care company will result in UnitedHealth owning an operating a Brazilian network of hospitals and clinics.
Concerns about Concentration of Market Power and PricesIn an increasingly financialized country, the media has featured concerns that the trend towards corporate physician practice might result in increasing market power for a few large corporations, and hence increased prices.  For example, in August, Anna Wilde Matthews 
reporting for the Wall Street Journal, noted
 Hospitals say the acquisitions will make health care more efficient.  But the phenomenon, in some cases, also is having another effect: higher  prices. 
As physicians are subsumed into hospital systems, they can get paid  for services at the systems' rates, which are typically more generous  than what insurers pay independent doctors. What's more, some services  that physicians previously performed at independent facilities, such as  imaging scans, may start to be billed as hospital outpatient procedures, sometimes more than doubling the cost.
  
The result is that the same service, even sometimes provided in the  same location, can cost more once a practice signs on with a hospital.
Major health insurers say a growing number of rate increases are tied to physician-practice acquisitions. 
As Ms Matthews also 
reported for the Wall Street Journal, state regulators are beginning to worry about acquisitions of doctors' practices by hospital systems may drive up prices. 
California's attorney general has launched a broad investigation into  whether growing consolidation among hospitals and doctor groups is  pushing up the price of medical care, reflecting increasing scrutiny by  antitrust regulators of medical-provider deals. 
Concerns about Care QualityConcerns about whether physicians who must practice under the command of corporate executives will be able to put patient care ahead of corporate interests are also appearing, but not yet as prominently. 
For example, Steve Twedt, writing for the Pittsburg Post-Gazette in September, 
looked into whether the multiple practice acquisitions by the area's two biggest ostensibly non-profit health care corporations might affect patient care.  He first noted "competition between Highmark and UPMC for doctors, and health care overhaul that is steering doctors into larger systems...."  Then he suggested that this has lead to marked discontinuities in patient care when physicians switch employment,
Out of the blue, people will learn their doctor has left a practice with  little or no explanation, and without a forwarding address. When a  physician effectively disappears, the cause usually is tied to the  physician's employment contract, says a local health care attorney.
These cases of apparently vanishing physicians may be due to the contracting practices of physician employers, particularly large health care corporations.  The lawyer Mr Twedt interviewed explained,
most physician contracts now contain clauses that prohibit doctors from soliciting patients if they leave a practice.
While  it's not always clear what constitutes 'solicitation,' it generally  means departing physicians cannot contact their patients to invite or  entice patients to follow them to their new location. They also cannot  take their patient list with them, since that is property of the  practice.
'I would imagine the doctor wouldn't contact them because he can't, or he doesn't have their address,' said Mr. Cassidy.
Contracts  also often require that doctors cannot practice medicine within 10  miles of the previous practice office, and sometimes the required  distance is even greater. Nor can they give out information about the  practice they're leaving. Violating these contract terms could mean a  financial penalty, such as loss of severance pay.
Finally, and most troubling, cardiologist blogger Dr Melissa Walton-Shirley
 recounted in some much more colorful language some consequences of cardiology practices which were acquired by large hospital systems.  She noted...
 
Referral Decisions Influenced by Management Edicts, but Maybe Not Patients' Needs
 
Physicians may be
sweating bullets over whether they are going to hit their benchmarks to  retain their salaries. My anxious friends are now calling me for more  referrals and more practice support.  They take any transfer I give them.... 
They may
 morph from human flesh into a Rubik's cube of relative value units  (RVUs), the formula through which all future salaries and bonuses are  calculated.
Resulting Loss of ContinuityIndependent cardiologists opened office doors to find their patients  who were anticipating decisions on timing of defibrillators, caths, or  medical therapy had undergone testing at other facilities. Those tests  were interpreted by cardiologists who were in no way connected to their  care, their referrals to unfamiliar testing venues now incentivized by  hidden contractual microformulas. They were evaluated far away from the  familiar eye of their long-time cardiologists. 
SummaryBack in the day, most physicians who took direct care of patients did so out of practices they or other physicians ran and owned.  The majority of physicians who took care of physicians as employees worked for the military or the Veterans Administration, or took care of patients only part-time as faculty of medical schools.  In a country increasingly prodded by market fundamentalism, the last few years has seen a major change in health care:  more and more physicians are taking care of patients as employees of large corporations, more often for-profit.
 I should add, though, that the recent push towards corporate practice was not just due to market fundamentalism, but also seems to in part be due to provisions of the recent attempt at US health care reform, the Affordable Care Act, which called for care by large organizations called accountable care organizations (ACOs).   However, like some other major changes in health care in the US over the last few  years pushed by the increasing dominance of large corporations, this  one happened 
without any rigorous assessments of whether the benefits  for individual patients or public health would outweigh the harms, and  justify the costs. Justified by the realization, now mostly forgotten, that health care is nothing like an ideal free market (look 
here), direct health care used to be almost entirely provided by health care professionals, often working in small, non-profit community hospital settings.  In fact, the American Medical Association used to condemn the corporate practice of medicine.  In addition, the corporate practice of medicine used to be illegal in many US states (look 
here).
We have changed all that, without too much thought, and without any rigorous assessment.  Now it seems increasingly likely that these changes are just increasing health care costs, and probably will cause worsening patient care and will worsen patients' and the public's health. 
As Dr Melissa Walton-Shirley wrote more vividly, 
Monopolies never meant to be planted in gardens so small grew like bull  thistles, literally overtaking all the good things that small community  medicine had to offer. They are now barely recognizable small towns with  the crabgrasslike metastasis of big corporations....
Will there be time to rethink this headlong rush before our health care options are restricted to that provided by one of a few huge corporations?  
True health care reform would reverse the trend to organize health care within ever larger, more bureaucratic, more monolithic, more dominant organizations.  Such reform is unlikely to happen until we see the nadir produced by the current bandwagon.