Sixty-five health and medical groups have formed a new commission to set tighter standards for testing and certifying the competence of the nation's more than 3 million health practitioners.

The current system of testing doctors and more than 100 kinds of therapists and technicians is in nationwide "disarray," Dr. Thomas Piemme of George Washington University, president of the new commission, said yesterday.

One result is that taxpayers and patients are paying for much "inferior" and "sub-par" care by uncertified or carelessly certified persons, said Dr. Harris Cohen of the Department of Health, Education and Welfare. HEW is a likely source of funds for the new effort.

Among the groups that most need new nationwide standards of competence, Cohen said, are the medical technologists and X-ray technicians responsible for the accuracy of millions of vital medical tests.

The 65 groups that joined in Miami this month to form the National Commission for Health Certifying Agencies include the American Medical Association: American Dental Association, American Hospital Association, and societies of physicians' assistants, dental hygienists, nurse-midwives, nurse-anesthetists, optometrists, physical and occupational therapists and other technicians.

"Certifying" is the process by which health professionals are examined by private, nonprofit boards of examiners on their ability in specialized fields. It is not the same process as official licensing: testing, then approval by a state government body.

But not all health practitioners have state licensing boards and - except in a few cases, including physicians and physicians' assistants - state examiners vary widely in their standards and requrements, Piemme and Cohen told a news conference.

Also, many state licensing boards - including those for physicians - examine only for general competence, not for specialized knowledge in the field in which the practioner actually ends up working.

As a result, Piemme said, some health professions now certify for competence others don't: some give objective tests, others don't some so-called certifying bodies lack independence are dominated by the professionals they are supposed to judge, and pass-fail rates vary widely and may be changed arbitrarily.

Also, he said, some certifying bodies - like the one for doctors specializing in family practice - now require periodic recertification based on retesting or evidence of continuing training. But many health groups have no such system.

"Our position in HEW" is that periodic reassessment or re-examination of all health professionals is needed to protect the public, Cohen said. One condition of membership in the new commission is that a profession move toward some kind of reassessment.

The commission's formation was the culmination of seven years of effort by the health groups and HEW. Piemme called William Samuels, executive director of the American Society of Allied Health Professions, the "father" of the new group of his direction of a crucial steering committee.

One large group not part of the commission is the main body of American nurses, though some specialized nurses' groups are included. Samuels said he thinks the nurses will join soon.