The number of patients using the nation's first physician-aided suicide program, Oregon's Death with Dignity Act, has continued to grow since voters first approved the law nearly two decades ago.

A new study shows a 12 percent yearly increase in lethal prescriptions from 1998 to 2013, with an unexplained jump of nearly 30 percent in 2015. The research doesn't include 2016 numbers, which haven't been released yet.

The growth reflects an increased awareness of the act among patients and physicians as more states adopt similar laws, said Dr. Charles Blanke, an Oregon Health & Science University oncologist and lead author of the study.

The study - one of the first detailed analyses of 18 years of Death with Dignity data - indicates the law is working as intended to give dying people a choice of how they want to die, Blanke said.

But it also shows too many people - 25 percent - said they were suffering too much pain, he said.

Blanke called that a tragedy, saying scientists must make sure patients aren't killing themselves because they're not getting help managing their pain.

Another tragedy: About 3 percent of patients used the law because the cost of chemotherapy was too high, the study found.

"What's worse than that - literally nothing," Blanke said.

Overall, 1,545 patients obtained a lethal prescription from 1998 through 2015. On average, 64 percent took the drugs. Almost all died but six people woke up and died later of natural causes.

The age range spanned 25 to 102 years, with a median of 71. Nearly 80 percent of the patients had cancer.

Most patients cited a decreased quality of life or loss of autonomy or dignity as reasons for using the law, according to the study, published Thursday in the Journal of the American Medical Association - JAMA Oncology.

Under the law, two physicians must certify that patients have a terminal illness and have only six months left to live. The physicians must determine that the patient is competent. If they have doubts, they can insist that the patient see a psychologist or psychiatrist.

Very few patients had a psychological consultation - only 5 percent.

Brian Johnson, a consultant for the California-based group, Seniors Against Suicide, and a former California commissioner on aging, said the study shows that patients were deeply depressed.

"This is a cry for help," he said. "Suicide is the number one indicator of depression."

Instead of writing a lethal prescription, the medical community should address the patient's emotional state, he said.

"We don't talk people off the edges of buildings in order to keep sidewalks clean," Johnson said.

"We intervene in their lives because this individual is dealing with something they've never before dealt with."

Blanke said research has shown that as many as three in four terminal patients are depressed.

"Either we're missing depression," Blanke said, "or it's possible that physicians agree that depression is not enough to make a person incompetent to make such an important decision."

The prescriptions - usually for 100 capsules of secobarbital that the patient must empty into water - aren't cheap, ranging from $3,200 to $7,700 depending on the pharmacy. Another possibility involves a triple cocktail of much cheaper drugs and costs about $400 total, but it's acidic and the patient stays in a coma for much longer.

The study showed that as a median, patients went into a coma within four minutes and died within 25 minutes.

The coma is like being anesthetized, said Blanke, chairman of SWOG, a worldwide network of scientists who conduct cancer trials. The blood pressure and pulse slow and the person doesn't react to discomfort, indicating they're not in pain, he said.

Almost all patients took the drugs at home, surrounded by loved ones. Physicians can't administer the drugs and the law doesn't require them to be there. In only 16 percent of cases, they were, the study shows.

Blanke has issued about 65 prescriptions since the law began. For years, he didn't ask patients if they'd like him to be present but then realized they might. Since he's asked, every patient has said yes. He's attended about 30 deaths.

"It has a profound impact on the prescriber," he said. "I find it quite moving. I end up being very close with the families."

Blanke thinks more people would want their physician present but that doctors don't ask.

Also, many physicians refuse to write Death with Dignity prescriptions, Blanke said, and won't

even

refer patients to a doctor who supports the law.

Physicians at Providence Health & Services, a Catholic medical group, do not write prescriptions of lethal drugs, for example.

The study shows that physicians aren't focusing lethal medications on disadvantaged people, an original concern about the law.

"Except for the 25 percent with poor pain control, the law is working nearly perfectly," Blanke said.

He said the area is for research to help physicians better control pain, learn why one-third of patients don't take the prescriptions and why some people experience a prolonged coma.

Five other states have laws supporting physician-assisted suicide. Another 25 are considering legislation, according to the advocate group, Death with Dignity.

The Oregon Catholic Conference, which represents the Archdiocese of Portland and the Diocese of Baker, expressed concern about the increase in patients.

"Assisted suicide laws make suicide socially acceptable," it said in an email. "As a result, Oregon's overall suicide rate is 41 percent higher than the national rate. Assisted suicide, like other forms of suicide, has negative effects on victims and families."

The conference called on physicians to improve pain care for end-of-life patients.

-- Lynne Terry