Study highlights difficulty of isolating effect of prayer on patients

The results of a long-awaited scientific study aimed at measuring the effect of third-party prayer for hospitalized patients not only did not match the expectations of those conducting the study, but also may have raised more questions for researchers than it answered. Among them: Can even the most carefully designed trial measure prayer's effects?

The Study of the Therapeutic Effects of Intercessory Prayer (STEP), published online March 30 by the American Heart Journal, showed no positive effect from the use of third-party intercessory prayer on behalf of patients undergoing a specific type of heart surgery at six medical centers around the United States when compared with a control group who were not prayed for as part of the study.

Another unexpected result: Patients who knew they were being prayed for had somewhat more medical complications than another group who also had received prayer but were uncertain as to whether they had or not. Researchers had expected the reverse outcome.

STEP aimed to provide more accurate results than four previous trials that involved cardiac patients, the authors said. The results of those trials were mixed: Two found a beneficial effect of prayer; two found no benefit. The earlier studies were also criticized for having design flaws, the authors said.

But the study itself is unlikely to satisfy those who question whether the effects of prayer can be measured using conventional scientific testing. They ask: How do you define what constitutes a prayer? Are all forms of prayer equally effective? How do you design a "dose" of prayer that is the same for each patient? And how do you rule out the effects of the patients' own prayers or prayers from others not involved in the study on behalf of the patient?

About 95 percent of all the STEP participants - including a control group that was not prayed for as part of the study - said that they expected friends, relatives, or members of their religious institutions to be praying for them. About two-thirds strongly agreed with the statement, "I believe in spiritual healing."

The authors were careful to point out the limited conclusions that could be drawn from their study. "Private or family prayer is widely believed to influence recovery from illness, and the results of this study do not challenge this belief," the authors wrote. "Our study focused only on intercessory prayer as provided in this trial and was never intended to and cannot address a large number of religious questions, such as whether God exists, whether God answers intercessory prayers, or whether prayers from one religious group work in the same way as prayers from other groups."

For some involved in exploring the issues of spirituality and health, the new study only confirms their reservations. "Scientific studies are just not capable of showing that prayer works," says Dr. Harold Koenig, an associate professor of medicine and co-director of the Center for Spirituality, Theology, and Health at Duke University's Medical Center.

"I think that prayer absolutely does work and that God answers prayer and that we can continue to pray for our loved ones," Dr. Koenig says. "We should not think that science can answer every question there is."

The authors of STEP wanted to study the effect of intercessory prayer and whether knowledge that the patient was receiving prayer made a difference. In the study, 1,802 cardiac patients awaiting surgery at six medical centers were divided evenly and randomly into three groups. All the patients were told that they were involved in a clinical trial and gave their permission. Those in Group 1 received intercessory prayer after being told that they may or may not receive prayer. Those in Group 2 did not receive prayer after being told that they may or may not receive prayer (the placebo, or control, group). Group 3 received prayer after being told it would receive prayer.

The patients were prayed for by three Christian groups: two Roman Catholic (St. Paul's Monastery in St. Paul, Minn., and the Community of Teresian Carmelites in Worcester, Mass.) and one Protestant (Silent Unity of Lee's Summit, Mo.). Attempts to involve non-Christian faith communities in the study proved unsuccessful, the authors said.

The groups prayed from one to four times daily over a 14-day period beginning just before a patient's surgery. While individual prayers could differ, all participants were asked to specifically pray for "a successful surgery with a quick, healthy recovery and no complications." Those praying never met the patients they were praying for and knew only their first names and the first initial of their last names.

Results were measured in terms of the number of medical complications encountered by each patient after surgery. Just over half of the patients in the study reported postsurgery complications. To the researchers' surprise, the highest percentage (59 percent) was recorded among those who were told they were being prayed for.

The researchers said they were unable to explain that outcome. "The role of awareness [of prayer] needs careful further study," said Dr. Charles Bethea, a cardiologist and one of the study's coauthors. The authors speculate that knowledge of being prayed for "might have introduced performance anxiety or made them feel doubtful about their outcome," Dr. Bethea says. "Did the patient think, 'Am I so sick that they had to call in the prayer team?' "

"This study might be opening doors to show the power of mind-body interventions both positively and negatively," added Dr. Herbert Benson, an associate professor of medicine at Harvard Medical School and co-principal investigator for STEP.

The Office of Prayer Research, sponsored by the Association of Unity Churches in Lee's Summit, Mo., has collected some 400 scientific studies on the subject of prayer and healing. About 75 percent show prayer having a positive impact on health, says Bob Barth, director of the office. "It's so easy to jump to conclusions that prayer doesn't work," he says.

But rather than placing too much emphasis on any one clinical trial, he says, STEP should open up "so many more areas where research should be done," such as a study comparing the effects of people using a standardized prayer vs. people using their own prayers.

Dr. Koenig, who was not involved in STEP, says he hopes this will mark the end of clinical trials that try to study intercessory prayer. "There are so many problems with the study - theological problems," he says. "I think God does heal people, I'm convinced of that, I know that from my own experience ... I pray for my patients every single day, and I see things happening, and I'm excited about that."

He would like to see other research into the ties between religion and health to continue, including "less sexy" questions such as, "Do patients who have a chaplain visit before surgery do better after surgery?" Or, "If a doctor takes a 'spiritual history' of patients along with their medical history and supports their religious beliefs, will it make a difference in medical outcomes?" Patients, Koenig says, have "tremendous spiritual needs that are not being met in the hospital."

According to a nationwide US government survey of complementary and alternative therapies released in 2004, 43 percent of American adults pray for their own health and 24 percent report having had others pray for their health.