Medical care in this country is now being reshaped by a variety of forces that are changing not only the organization and financing of the system, but also the way doctors think and practice. Whether this will be good for patients in the long run remains to be seen, but there are reasons to be concerned.

Some of the major trends are:

a growing surplus of physicians in many fields and many parts of the country;

a shift from fee-for-service solo practice to new patterns based on prepayment contracts and group management;

the increasing use of outpatient instead of hospital facilities;

a turn toward a competitive price-sensitive market in health insurance and hospital care.

Whatever else they may do, these developments can affect the relation between doctors and patients in ways that do not augur well for the public interest.

The rapid expansion of medical manpower over the past two or three decades has obviously improved the accessibility of medical services in many places, but it is not an unmixed blessing. Too many doctors may be no better, or even worse, than too few because the relations between doctors and patients cannot be governed by the rules of the free market.

Consumers of medical care (patients) need to trust the suppliers (physicians) for advice about the services they need. Often that trust becomes a total dependence on the physician for health, comfort or even life itself. Physicians have an obligation, above all, to serve the interest of their patients, but they also have considerable power to generate their own demand.

When there are too many physicians competing for too few patients, one can expect the ethical standards of medical care to be strained and the focus to shift from a primary concern for patient's needs to more preoccupation with the physician's economic interests. This explains why so many physicians who feel economically threatened are now investing in facilities to which they refer their patients, such as radiologic centers, diagnostic laboratories and ambulatory surgery centers.

Professional ethics and self-regulation are a protection against gross mistreatment of patients, but medical practice involves large gray areas where there is much room for individual judgment and where clear standards have not been established. Perverse economic incentives need not cause grossly inappropriate behavior with undesirable consequences for the quality and cost of medical care. As for physician investments in clinical facilities, organized medicine is uneasy about it, but not yet willing to declare it unethical.

The new financial arrangements may also place physicians in ethically uncomfortable positions. Prepaid care puts a premium on cutting costs. To the extent that this can be accomplished by efficient management and the avoidance of unnecessary procedures and hospitalization, there is no conflict with the fiduciary obligations of the physician to the patient.

However, when the financial incentives and management pressures are strong enough, the physician's clinical judgment can be influenced. An oversupply of physicians makes doctors more vulnerable to those incentives and pressures, and the increasingly competitive and commercialized market for prepaid care tends to generate ever stronger management insistence on cutting costs. The shift in ownership of HMOs to investor-owned corporations further adds to the risk that physicians in some prepayment plans will be encouraged or forced to cut corners.

Consumer resistance to deficiencies in quality of service, an important protection of the public interest in most markets, is not likely to be very effective in health care. In the first place, consumers are usually not able to detect subtle but important differences in the technical quality of medical services; they must depend on their physician for advice on such matters.

Secondly, medical care consumers usually do not, and often cannot, pay out of pocket for the services they receive, thus limiting their choices and their leverage on the providers. This is particularly true of indigent patients, and yet they are most likely to receive inadequate medical care.

To protect the profession and the public against the risks inherent in the new competitive health care market, I believe that the public needs to rely on the primary commitment of physicians to the welfare of their patients. The counsel of devoted physicians will be of critical importance in helping patients navigate the shoals of an increasingly commercialized medical care system.

To assure the public of its commitment, and to make its own purposes clear, the medical profession ought to publicly renounce any commercial ties with clinical facilities to which physicians direct their own patients. Several states have passed, or are considering, legislation to prohibit such practices; these and other similiar initiatives deserve the support of the public and the profession.

Physicians also should avoid contractual arrangements with health care insurers or HMOs that give lay managers control over professional behavior. Prepayment arrangements involving physicians make sense for patients only when risks are shared by large groups of physicians and when those groups are self-managed and held to professional standards of quality. The public should expect adequate assurance of quality, but must understand that quality is most likely to be protected when medical practice conforms to professional rather than purely economic norms.

Finally, government and the profession will jointly have to confront the problem of medical manpower. The market will not adequately deal with the impending oversupply of physicians. We shall have to devise acceptable means of adjusting supply to need or else face the risks of an inevitable deterioration in professional standards.