The nation's health bill is rising so fast that it is hastening the day when doctors will have to make far more decisions about who shall live and who shall be allowed to die, five health leaders agreed here this week.

They spoke at a news conference at the American Association for the Advancement of Science to unveil a major health issue, out today, of the association's noted weekly journal science.

Dr. Phillip Abelson, Science's editor and head of the Carnegie Institution of Washington, warns in an introduction to the issue that current medical research and care may be focused too strongly on prolonging "meaningless existences" at huge cost.

But the growing problem of "who shall live?" will affect many more persons than the very ill whose lives may seem meaningless, said Dr. Howard Hiatt, [WORD ILLEGIBLE] dean of the Harvard School of Public Health.

Because neither the government nor insurers nor individuals will be able to pay for all the things doctors are learning to do, "We inevitably shall be asking, 'which of our citizens must be deprived of life-saving measures?" Hiatt said. "I am convinced we cannot evade this issue."

"It's going to on now," said Robert Ball, former federal Social Security commissioner, now senior scholar at the Institute of Medicine of the National Academy of Sciences.

"Doctors are deciding against extraordinary steps to keep persons alive. Or whether or not go give this or that person an organ. A lot more is done than is ever made formal."

Such decisions are made "often" and are affecting millions, said Dr. Ernest Saward, professor of social medicine at the University of Rochester.

This is because there is "rationing" of care partly by who has access to doctors and who can pay, he said. "For example, blacks only get hip replacement operations at the one-tenth the rate of whites, but they have just as many hip problems. I think 40 or 50 million people are underserved by the health system because they don't have the means."

Compared to other age groups, the elderly and early adolescents are underserved, added Dr. David Hamburg, head of the Institute of Medicine.

The main solutions offered by these speakers and Dr. Gilbert Omenn, assistant director of President Carter's Office of Science and Technology Policy, are: prevention, national health insurance, cost control and assessment of new medical methods to eliminate the useless and wasteful.

Saward called the search for more effective ways to prevent illness and accidents "the quest of the next decade."

Ball called national health insurance essential, and said it was "important to keep any means test to the absolute minimum, because it's very, very difficult to maintain high quality service for all in any plan that singles out the poor people" in a separate category, like today's Medicaid which, he said, encourages "Medicaid mills."

Control of costs, he said, will require "control of services," that is, control over adding costly buildings and equipment and the overuse of expensive medical specialists.

For example, he said, "the scope of personal preventive services covered at the beginning" of a new national health plan might be narrow, but "a special board could be established to approve additional services for coverage after they have been tested and evaluated."

Hiatt - summarizing an article by Dr. Howard Frazier and himself - urged rigorous evaluation of all medical and surgical procedures and use only of those that pass muster as beneficial and cost-effective.

He urged Congress to pass a bill proposed by Sen. Edward M. Kennedy (D-Mass.) - or a "somewhat less comprehensive" bill by Rep. Paul Rogers (D-Fla.) - to establish a federal center for heart attack victims, operations finance tests of new measures, for example, costly coronary artery surgery for health attack victims, operations often done uselessly now, according to studies.

Omenn backed such testing, but said the administration opposes the Kennedy and Rogers bills because many such steps are already being taken.

Hiatt replied that the Harvard School of Public Health's Center for Analysis of Health Practices - considered the leading such center among universities - has been consistently turned down on its requests for federal support to broaden its studies.

Yet, he said, "Many current practices in medicine and surgery have not been evaluated. Radical mastectomy" - removing the breast and adjacent structures - "remains the most commonly practiced procedure for breast cancer, though there is no persuasive evidence that it is better than a simpler treatment.

"Tonsillectomies are being done less frequently, but one can still seriously question the need for close to a million a year. Last year over 80,000 Americans had coronary surgery at a cost in excess of $1 billion dollars," Hiatt said.

"High costs make it necessary for us to set priorities, and we need more federal support for the needed evaluation. The cost of not undertaking such research will be greater than undertaking it."