In all the current discussion - by government leaders, union leaders and columnists - of the need for national health insurance, one voice has yet to be heard. The public has yet to give any indication that it sees such a program as a high-priority matter.

In fact, public-opinion polls consistently indicate that most Americans consider themselves well served by our health-care system. For example, in late 1977 the Univeristy of Chicago released the results of a poll showing that 88 percent of the public was satisfied with its health care. Other polls reinforce the conclusion that the over-whelming majority of Americans are "satisfied" or "well satisfied" with health care in the United States, and are opposed to national health insurance if it means an increase in taxes.

It doesn't take too much digging to find the reason for this lack of enthusiasm: Nearly every American is already protected by some form of health insurance. The fear of possibly costly healt-care bills does not prey on most Americans, because they are already protected adequately.

In a sense, the nation already has a national health-insurance plan, which was developed by trial and error. The American "plan" - as it exists now - has the advantage of being paid for by private enterprise, by employer-employee contributions, not by the government through increased taxes.

To give health insurance to Americans who are currently unprotected - they represent no more than 10 percent of the popultion - some advocates are saying in effect: Scrap the present system and put in its place not a national health-insurance program but a national health-care delivery system. These advocates would eliminate the present system of privately financed, professionally responsible health-care providers and replace it with a totally government-controlled system. This view seems particularly ironic today when government involvement as a solution to any problem has come under attack form all sides - and with good reason, since the government's administrative efficiency is, to put it mildly, questionable.

The few gaps in the present system can be used closed through the cooperative efforts of the government, insurers and professional societies. But it, after a thorough airing of the subject, the American public decides that it wants a national health-insurance program, then the American Medical Association has a plan that it has kept before Congress since 1970. The AMA approach has these basic principles:

Comprehensive catastrophe coverage for everyone.

Continuation of employment-based insurance funded by the private sector, coverage for the unemployed to be subsidized by the government.

Minimum federal funding and minimum federal administration.

Freedom of choice to be preserved. On the one hand, the patient must be allowed to choose his or her own physician and the type of coverage - whether Blue Cross-type insurance or a health-maintenance organization. On the other hand, the physician must have the right to choose his own way to run his practice.

No Social Security financing or administration; coverage under the AMA bill should be furnished by private insurers on a risk and underwriting basis.

Other principles, including a sliding co-insurance provision, with the poor paying nothing, are intended to act as cost-control mechanisms. But these mechanisms in themselves could not arrest the escalation of health-care costs.

The rise in medical costs is compounded by a technology that is constantly becoming more sophisticated as each new discovery creates the need for more complex instruments and equipment. Each technological advance brings new hope to patients who formerly had not been treatable, and so consumer demand increases. Finally, inflation works its way on the health-care industry just as in other parts of the economy. As just one example, 60 percent of a hospital's costs are labor, yet no one expects that interns, nurses and other hospital employees should return to the wage levels of 20 years ago, when they were notoriously underpaid.

The escalating cost of health care is not simply a matter of holding down physicians' fees or hospitals' expenditures. To explore the many causes of health-care cost increases, the AMA sponsored a commission on the cost of medical care, which for two years studied the problem of rising costs. The complexity of the problem led that blue-ribbon panel, composed of economists, business and labor leaders, lawyers and physicians, to make 48 specific recommendations. Few could be accomplished through a nationalized health-care delivery system because so many of them involve the interactions of government, consumers, physicians and others on a variety of levels, some far removed from simple financing.

The consequences of a complete restructuring of our health-care system would be enormous and, once accomplished, there could be no turning back, even if the experiment were unsuccessful. The AMA knows that there are gaps in the present system, and we want to correct them, but our prescription is a moderate one, not radical surgery. Moderation alone can allow for orderly development, with changes made in the system only as need becomes evident.