Strong religious faith can comfort people who are dying of cancer, allowing patients to find meaning in their suffering and easing their passage out of life, experts say.

But faith can be a "double-edged sword," says nurse Carol Taylor, director of the Center for Clinical Bioethics at Georgetown University. Some terminally ill patients latch on to stories of biblical miracles, hoping against hope to be cured, instead of using their little remaining time to make peace with God and loved ones.

Yet even Taylor, who has counseled many dying patients, says she was surprised by the findings of a study in today's Journal of the American Medical Association, which examined the choices of dying cancer patients who rely strongly on their religious faith to cope with their illness.

These patients were three times more likely than others to receive intensive, invasive medical procedures — such as being hooked up to a ventilator or getting cardiopulmonary resuscitation when their hearts stop — even in their last week of life, the study shows.

The new study shows that those who used "positive" religious coping — such as those "seeking God's love and care," as opposed to people tormented by the belief that God was punishing or abandoning them — were more likely to want doctors to do everything possible to keep them alive. They also made fewer preparations for death, such as filling out "do not resuscitate" orders, writing living wills or giving someone power of attorney, according to the study of 345 patients. The patients lived a median of about four months after entering the study.

Interestingly, those tormented by spiritual questions were not more likely to get aggressive care, the study shows.

Although researchers considered other factors that could have affected patients' treatment choices, such as race, income or psychological distress, religion remained the most important factor.

The religious people in the study may have believed that God could work through aggressive medical procedures, says study author Holly Prigerson, associate professor of psychiatry at Harvard Medical School.

"We suspect they are waiting for a miracle," Prigerson says. "They are more likely to think that life is sacred and that their job is to prove their faith to God by staying alive as long as possible, so miracles can be performed."

Yet aggressive procedures may intensify the physical suffering of people whose bodies are shutting down, says Taylor, who was not involved in the new study. Patients who are hooked up to ventilator machines aren't able to talk, which can prevent them from having meaningful conversations with the people they're leaving behind. The caregivers of patients who die in these circumstances often suffer more grief, as well, according to background information in the study.

"Needlessly prolonging dying isn't a positive thing," Taylor says. "I would think someone with a mature religious faith would be more at peace, more able to accept death. Certainly, you wouldn't be afraid to die."

A growing number of studies show that doctors, nurses and chaplains could do much more to ease the spiritual suffering of terminal cancer patients.

A 2007 study in the Journal of Clinical Oncology by Tracy Balboni, a co-author of the new paper, found that more than 70% of patients felt their spiritual needs weren't met by hospital chaplains or others in the health care system.

Only about one-third of advanced cancer patients are told how long they can expect to live, an omission that can lead to needless physical and spiritual suffering, according to an October JAMA study. More than 20% of advanced cancer patients in the Medicare program start a new chemotherapy regimen — which can cause intense nausea, vomiting and weakness — within two weeks of death.

Many researchers are studying what causes some patients to get aggressive care in their final days.

Minorities, for example, are much more likely to get intensive care as they're dying, according to a study published last week in Archives of Internal Medicine.

Research shows that such last-ditch attempts to prolong life are actually a sign of poor quality medical care, says Harvard University's Amitabh Chandra. While intensive care units can be life-saving for critically ill newborns or young people who've been in a traumatic accident, for example, ICUs have much less to offer the very elderly or those with advanced cancers. Often, seriously ill patients who enter the ICU gain only a few extra days of life.

Prigerson says her research suggests that doctors should be sensitive to the ways that religion shapes a patient's treatment choices, and consider including hospital chaplains or psychiatrists in conversations with patients.