A study of more than 1,000 nursing home patients has found that both doctors and nurses often let patients die.

The study's authors, a doctor and a statistician at the University of Washington, say their findings seem to refute the common accusation that doctors too often prolong life "at any cost."

In fact, many doctors concede, doctors sometimes prolong life too long, and they sometimes consciously let a painful life end.

In today's issue of the New England Journal of Medicine, Drs. Norman Brown and Donovan Thompson tell how they combed the charts of 1,256 patients in nine Seattle nursing and retirement homes. Over two years, 190 developed a high or continuing fever at some time.

But active treatment - use of antibiotics or hospitalization or both - was ordered for only 109. No such treatment was ordered for 81 patients, or more than 40 per cent.

Of those treated, 9 percent died. Of the untreated, 59 per cent died.

Brown and Thompson conclude that the decision not to treat some fevers "was part of an intentional plan by doctors and nurses."

In some cases the nurse did not even call the doctor to report the fever. Sometimes the doctor had alreadly indicated that a fatally ill patient shouldn't be vigorously treated. These doctors had written such phrases as "patient terminal, no effort made to prolong life" or "no heroics" on a patient's chart.

Brown and Thompson say they hope their study will encourage doctors, patients and families to open dialogues on the subject of when not to treat.

It has been his experience, Brown said, that when asked for advice, families usually give answers ranging from "treat" or "do not treat" to you're the doctor" or "do not treat but do not tell us . . ." Most often, he said, families want the doctor "to take the ultimate responsibility."

Most doctors apparently are willing. The Seattle researchers say two recent surveys of health professionals found that 50 to 70 percent "are disposed to withdraw or withhold life-prolonging treatment" in some cases and 30 percent would favor enthanasia, or mercy-killing, in some circumstances.

Dr. Arnold Relman, editor of the New England Journal, says in an editorial in the same issue that every experienced doctor knows there is "a time to recognize that further resistance would be inhumane as well as futile."

Relman suggests that a person facing a terminal illness may want to name a trusted proxy - a relative, friend, lawyer or docctor - to join the doctor in charge when it comes to making the final decision.