It is unclear why those who pray prefer more aggressive end-of-life care
People with strong religious beliefs appear to want doctors to do everything they can to keep them alive as death approaches, a US study suggests.
Researchers followed 345 patients with terminal cancer up until their deaths.
Those who regularly prayed were more than three times more likely to receive intensive life-prolonging care than those who relied least on religion.
The team's report was published in the Journal of the American Medical Association.
It suggests that such care, including resuscitation, may make death more uncomfortable.
Just over 30% of those asked agreed with the statement that religion was "the most important thing that keeps you going".
The researchers from the Dana-Faber Cancer Institute found these people were the least likely to have filled in a "do not resuscitate" order.
As well as receiving resuscitation, they were much more likely to be placed on mechanical ventilation in the last few days of life.
While previous US research has shown that the religious tend to support intensive end-of-life care, little work has been done to show whether they actually receive this.
However, work has been done which suggests that intensive intervention in the last few weeks and days before death may reduce a patient's quality of life.
Researchers at the University of Pittsburgh School of Medicine found that treatments such as ventilator support, resuscitation, having a feeding tube and non-palliative chemotherapy were associated with more psychological and physical distress.
The patients' chances of dying in their preferred place were also reduced.
The researchers in this latest study stressed that religion had been widely associated with an improved ability to cope with the stress of illness.
But "because aggressive end-of-life cancer care has been associated with a poor quality of death and caregiver bereavement adjustment, intensive end-of-life care might represent a negative outcome for religious copers", defined as those who regularly used prayer or meditation for support.
"These findings merit further discussion within religious communities, and consideration from those providing pastoral counsel to terminally ill patients with cancer," wrote lead researcher Holly Prigerson.