People who are religious are more likely to choose life-prolonging care when they are near death, a study suggests.

Researchers looked at 345 patients with advanced cancer, focusing on their use of religious coping at the start of the study, and whether they received intensive medical care during their last week of life.

"It's relying on your faith to help you deal with terminal illness," said study author Holly Prigerson of the Dana-Farber Cancer Institute in Boston.

Patients who reported a high level of positive religious coping were about three times as likely to receive mechanical ventilation and life-prolonging care than those who disclosed a low level of coping through faith, the team reported in Tuesday's issue of the Journal of the American Medical Association.

In the study, more than half of participants said they prayed, meditated or studied religion daily.

While the sample of participants was diverse in terms of socio-economic, geographic and ethnic factors, one limitation of the study was that the group was predominantly Christian, the researchers acknowledged.

Patients said they were Catholic, unspecific Protestant, Baptist or other.

Turning to one's faith could help comfort patients, the researchers wrote, but aggressive end-of-life care, which can be hard on the patient and their caregivers, "might represent a negative outcome for religious copers."

The findings suggest that it's personal beliefs such as religious coping — not  economic factors such as health insurance coverage — that dictate use of aggressive care, Prigerson said.

"We need to understand that our patients are relying on their faiths to understand their illness and to make decisions — and difficult decisions — about care at the end of life," said study co-author Dr. Andrea Phelps of the Beth Israel Deaconess Medical Center in Boston.