March 31, 2006 -- In the largest study of its kind, a group of researchers presented data that are sure to stir debate about a long-held spiritual tradition: praying for the sick.
The study examined the effects of intercessory or "distant" prayer -- prayer provided on another's behalf -- on heart bypass surgery patients. It appears in this month's issue of American Heart Journal.
"Prayer had a neutral effect" on the patients' overall outcomes, researcher Charles Bethea, MD, with the Oklahoma Heart Institute in Oklahoma City, said in a news conference.
Knowledge of Prayer
However, knowing that someone would pray for you seemed to have a negative effect on complication rates. Patients that were certain that others would pray for them had a higher rate of complications than patients who were uncertain but did receive prayer.
Patients who were uncertain whether anyone was praying for them had similar complication rates -- regardless of whether they received prayer or not.
Those who were certain they were being prayed for "had an unexpectedly high complication rate," Bethea says. "This aspect of awareness needs further study ... such a significant finding begs for more evaluation."
"The reality of this study is that the group they thought would do the best actually did worse," says Mitchell Krucoff, MD, a cardiovascular specialist at Duke University School of Medicine who was not involved in the study. Krucoff has conducted his own studies of prayerstudies of prayer.
"It may be that it was the effect of the prayer itself," Krucoff tells WebMD. "Or it could be that the Lord works in mysterious ways, and what we think of as a negative outcome is really a good outcome in the larger picture -- that which doesn't kill us makes us stronger."
However, stress could have been the cause, he says. "Think about it, the night before surgery they were told about the prayer therapy, then asked not to tell anyone. They were going into major heart surgery -- yet they knew something they could not mention to anyone."
"It's possible that knowledge about the prayer might have induced a form of performance anxiety in the patients, or made them feel doubtful about their outcome," Bethea says. "They may have wondered, 'Am I so sick that they had to call in the prayer team?'"
Examining Prayer's Effects
Over the past decade, a number of studies have looked at this issue - whether intercessory prayer can affect a heart surgery patient's recovery.
"Mind-body studies like these are to understand how stress affects the disease state and how we might use therapies to counteract stress," says researcher Herbert Benson, MD, founder and director of the Mind/Body Institute in Boston and a professor at Harvard Medical School.
"This study might be opening doors to the positive and negative effects of mind-body interactions," Benson says.
The results of prayer studies have been mixed, Bethea adds. Two studies have shown a benefit from prayer, but two found no effect. "There have been limitations with those studies," including small numbers of patients enrolled, he notes.
This newest study involved patients in six academic medical centers across the country. A total of 1,800 surgery patients scheduled for heart bypass surgery were assigned to one of three groups:
- Group 1: Patients received intercessory prayer but were told that they may or may not be prayed for.
- Group 2: Patients did not receive intercessory prayer, but (like Group 1) were told that they may or may not be prayed for.
- Group 3: Patients were told that they definitely would be prayed for and received prayer.
Neither the patients' families nor the hospital staff was told which group the patients were assigned to. Patients were asked not to discuss their group assignment with anyone.
Three Christian groups (two Catholic and one Protestant) provided prayer throughout the study. Beginning at midnight before each patient's surgery - and for a 14-day period postsurgery - each member of the prayer groups offered up a standard prayer: "For a successful surgery with a quick, healthy recovery and no complications" for each patient.
"A patient might have 70 people praying for them," notes Father Dean Marek of Mayo Clinic in Rochester, Minn., in the news conference.
Patients Under Stress
When researchers analyzed the outcomes of each group, they found this:
- 52% of Group 1 and 51% of Group 2 patients had at least one complication.
- 59% of Group 3 patients had at least one complication and significantly more cases of atrial fibrillation, compared with Group 1 (the other prayed-for group).
Atrial fibrillation is an abnormal heart rhythm and a complication that typically occurs in 30% to 40% of patients, Bethea explains. "It is a common complication in bypass surgery. It generally causes no serious side effects and, when treated with medication, typically resolves within a few weeks."
Anxiety triggers the onset of stress hormones like epinephrine, which could cause atrial fibrillation, says Sidney Levitsky, MD, with Beth Israel Deaconess Hospital in Boston. "The increased rate of atrial fibrillation is probably real rather than random. It raises the question whether we frightened [the patients] more than they needed to be."
Major complications and death rates were similar across all three groups, researchers note.
Prayer Studies Scrutinized
Their study has been criticized by other journal editors, the researchers admit. "A balanced study would have a Group 4 -- a group that knew they definitely weren't being prayed for," says Bethea. "We were concerned that would increase the patient's stress level."
Prayer's effect may be larger when people pray for themselves, says Benson. "It often breaks the train of everyday thought and invokes a relaxation response. We were not studying relaxation response in this study, but others studies have shown it to be beneficial."
Father Marek was "not terribly surprised" at the finding, he says. "Chaplains are involved face-to-face all the time with patients in hospitals. Prayer takes on a different attitude and approach when we are praying with patients and families. ... In the catalog of types of prayer, intercessory prayer would be at the bottom of the list in terms of meaning and effectiveness."
"People have been praying for others for centuries," Marek says. "If prayer is able to influence health care outcomes, then indeed it did so long before outcomes were ever measured ... and will likely skew outcomes in the future."