Researchers said their findings show that most seriously ill people who ask about doctor-assisted suicide are actually afraid of pain or other issues and need to be reassured.
"People usually change their minds," Dr. Susan Tolle, director of the Center for Ethics in Health Care at Oregon Health & Science University, said in a telephone interview.
"The doctors are never taught in medical school what to do, what to say, how to help people with their fears that led to their request," said Tolle, who lead the study.
Tolle and colleagues studied the effects of the 1997 Oregon "Death with Dignity Act," which made Oregon the only state with legalized assisted suicide.
It has been controversial, with patients' rights groups saying it should be copied across the nation, but others saying it cheapens life and could end up making the disabled and seriously ill disposable.
Tolle's team did not look at the legitimacy of the legislation, but instead examined why patients sought a doctor's help in dying.
They cited surveys that suggest about 1 percent of patients request physician-assisted suicide, and one in 10 of those patients receive and take the lethal prescription.
"Ultimately, less than one in a thousand Oregonians takes a lethal prescription. In other words, while legal, the option is not commonly used in this state," Dr. Paul Bascom, a professor of medicine who worked on the study, said in a statement.
The researchers said nationwide an estimated 25,000 terminally ill people ask their doctors for lethal prescriptions each year.
"Twenty-one percent of primary care physicians said they had a request in the prior year," Tolle said.
Writing in the Journal of the American Medical Association, Tolle's team looked at the case study of a 47-year-old man with amyotrophic lateral sclerosis, ALS, or Lou Gehrig's disease.
It is an incurable and inevitably fatal disease that progressively leaves a patient paralyzed and, eventually, unable to breathe.
The patient, identified only as "Mr G." to protect his privacy, asked his doctor about physician-assisted suicide. The doctor did not approve and did not know what to do.
"When the patient made a request, he walked away. He did not explore the reason behind the request," said Tolle, who listened to recorded transcripts of Mr. G's meeting with his doctor.
The patient did not want to die quickly, but was afraid.
"It turns out he was scared to death to die like his father, who died of colon cancer," she said. "He died in the hospital a truly horrible death with inadequate medication, on a lot of machines in a great deal of pain."
Mr G. did not know that ALS does not cause a painful death. "So he was not even given adequate information. He was not given information about what could be done for him. He feared a painful death more than anything else," Tolle said.
"Once he was sure he could be comfortable, he was happy enough to have his death occur from natural causes without pursuing physician-assisted suicide. But this was nearly a missed opportunity to reduce this man's terrible suffering."
Patients also incorrectly believe that physician-assisted suicide involves a lethal injection, she said. "It's not legal in Oregon, let alone anywhere in the United States," she said.
They are given a prescription and told an overdose will kill them, then allowed to decide what to do.
"What a doctor needs to do is take a deep breath and say 'Why do you ask?' rather than indicating either that you are willing to participate or that you are unwilling to participate," Tolle said.
"The doctor should ask, 'What are you afraid of? What are you worried about?"' she advised.
By Maggie Fox