July 14, 2005 -- A new study of prayer and heart health has researchers asking more questions than they can answer right now.
The findings didn't show a benefit for the main result measured. But that may not be the end of the story.
"This is a first step, not a final, conclusive work," researcher Mitch Krucoff, MD, FACC, FCCP, tells WebMD.
"We are very early in our scientific understanding of how important prayer works for healing," he says.
Krucoff is a professor of medicine and cardiology at Duke University Medical Center. He also directs the cardiovascular devices unit at the Duke Clinical Research Institute. The study appears in The Lancet.
The study included 748 people. They were due to get a heart procedure -- a cardiac catheterization -- to check for blocked arteries. Three out of four also got other procedures to reopen those arteries.
The researchers asked a dozen congregations from a variety of faiths around the world to pray for 371 of the patients. The other 377 patients were not put on official prayer lists.
Everyone got standard medical care. Some patients also got bedside music, imagery, or touch therapies.
The patients were followed for six months.
All groups had similar outcomes in the study's main measurement: a combination of major in-hospital heart problems, rehospitalization within the next six months, or death.
But other measures showed possible benefits.
While there was no positive result on prayer for the main result, Krucoff says there was a suggestion of benefit in other specific areas.
Emotional distress before the heart procedure and death six months after the procedure were lower in the music/imagery/touch group.
"These may be the world's most ancient healing traditions, but the clinical science we're using is what we would use for evaluating the most modern of therapeutics," says Krucoff.
"What real science in this area does is set the stage for us to learn something and then continue to investigate until we really begin to understand the role of the human spirit in the context of high-tech cardiovascular care," he says.
Methods, Groups Varied
The study included Buddhist, Muslim, Jewish, and Christian congregations around the world.
The patients' names were sent to the congregations within 30 minutes of assignment to the prayer group.
Congregations were free to pray for the patients whenever, whatever, and however they wanted. Some prayed for five days, others for as many as 30 days.
"We deliberately enrolled different denominations [and] different religions who were physically in different time zones, each of whom say prayers with different syntax during the day for different durations over a different number of days," says Krucoff.
"We left the content, the timing, and the duration of prayer up to the routine practice of each congregation. We did not dictate," he says.
Some groups may have prayed, "Thy will be done." Others may have prayed for the procedure to go well and the doctor not to make a mistake, says Krucoff.
"That whole range was covered across these prayer groups," he says.
Patients (or their friends, family, or acquaintances) were free to pray outside of the study, too.
Layers of Prayers
In the study's last year, a second group of congregations was enlisted to pray for the congregations praying for the patients.
"That two-tiered therapy appears [to have] an effect on six-month rehospitalization and death that suggests that it may behave differently than just the prayers said for a specific individual patient," says Krucoff. That finding needs further study, he says.
The patients weren't told who was in the prayer group and who wasn't.
The researchers gave them surveys to see which group the patients thought they were in. Two-thirds of those who weren't in the prayer group stated that they believed they were in the prayer group.
That belief could have affected the results. Krucoff says he and his colleagues will look at that possibility in the future.
"This, to me, is one of the exciting things about real, structured clinical data," he says. "We have a lot of unique descriptors and observations that will be very helpful in understanding these data to better guide future trials."
Many Questions Remain
"There is absolutely no knowledge of a real mechanism here," says Krucoff.
For instance, he says, "No one knows if you pray for 30 days, is that better than if you pray for five [days]? Or if you pray in one religious mode, is that better or worse than another?"
"What's fascinating, actually, is every single congregation basically has a dosing schedule for prayers for the sick," says Krucoff. Prayers might be said once a week, or for a month, or twice a day -- once alone and once in vespers with the whole congregation, says Krucoff.
It's not known if prayers made before the procedures were complete had an influence, write the researchers.
Can Science Understand Prayer?
"There are some limitations, and there's nothing wrong with that," Keith G. Meador, MD, ThM, MPH, tells WebMD.
Meador didn't work on the study. He is a professor of pastoral theology in medicine at Duke's divinity school. Meador is also a clinical professor of psychiatry and empirical sciences at Duke's medical center.
"I think there's a lot of work in religion and health -- spirituality and health -- that we need to be doing," says Meador.
"But I am skeptical about efforts to measure prayer and study it with standard empirical methods as employed by many of the prayer intervention studies," he says.
Definitions of prayer and study methods are important, says Meador.
"This finding should inform those of us who are working at the interface of spirituality, religion, and health... [about] the challenges of this work," he says.
"This should not affect the faithful person of whatever tradition in any way in their understanding of prayer," says Meador.