Some researchers believe that prayer helps patients, but their scientific study into the power of prayer didn't prove it.
Cardiologist Dr. Stephen Kopecky and other researchers followed 799 Mayo Clinic heart disease patients, half of whom were prayed for by others, although they didn't know it, and half of whom were not.
After six months, researchers found no significant differences between the two groups in the number of deaths, heart attacks, hospitalizations or strokes. The research is published Tuesday in the Mayo Clinic Proceedings, a journal published by the Mayo Clinic.
The findings drew immediate criticism as an attempt to measure God's will. Prayer and faith are deeply personal and the health benefits of prayer depend on the patient knowing about or participating in the prayers, said Dr. Greg Plotnikoff medical director of the Center for Spirituality and Healing at the University of Minnesota.
"I don't think we can randomize God," he said. "I don't believe we can truly understand God's will. And I don't think that prayer is another pharmaceutical agent."
Kopecky conceded that researchers were trying to measure things that humans may be incapable of measuring. But he said it's important to learn more about the effect of prayer on patients' health and well-being. After all, 97 percent of patients pray the night before they have heart surgery, he said.
"This is something people believe in, or at least they believe in it enough to do it," he said. "This is an important area to a lot of people."
Over the years, research on the effectiveness of prayer has produced mixed results - although generally the evidence indicates that it often does help. Kopecky said about 1,200 studies have examined what happens when people pray for themselves and what happens when they pray for others. He said that the majority found religious involvement and spirituality are linked to healthier lives.
Kopecky's study was conducted between July 1997 and October 1999. For half of the group, researchers assigned five people to pray for each patient at least once a week for 26 weeks. The other half of the study group had nobody assigned to pray. However, Kopecky conceded that researchers don't know if those patients had other people praying for them.
Researchers could discern no scientifically significant differences between the two groups. Even so, Kopecky said he found it intriguing that the patients who were prayed for fared slightly better overall. Of those in the prayer group, 25.6 percent experienced some negative outcome - death, a heart attack, rehospitalization or a visit to the emergency room - compared to 29.3 percent in the other group. Those differences were within the margin of error.
Kopecky said he was surprised to see any variation.
"I thought this study would be an exact even wash - that everything would turn out the same" for both groups. "Even the fact that it didn't is impressive," he said.
He has some important caveats about this research. It did not prove that prayer is useless - and it did not measure the power of God, he said.