Is there a therapeutic effect of remote intercessory prayer?

In 1872, Galton published the first known study on petitionary and intercessory prayer. He compared the mean age of death among males from various professions between 1758 and 1834. He hypothesized that if intercessory prayer was healing, he would see men from professions such as the clergy, missionaries, and the royalty to have longer lives, as it was common for these groups to be prayed for frequently. He found no statistical evidence that prayer prolonged life. Members of royal houses had the shortest life span while the clergy lived only slightly longer than men in other professions. Eminent clergy, however, lived shorter lives than either lawyers or medical professionals. He also compared rates of stillbirth between the praying and non-praying classes. Again, he noted no survival benefit of prayer. A flaw in this study is that the praying classes tended to be those with the most psychosocial stressors and hardships, which would tend to shorten survival.

In 1965, Joyce and Welldon conducted the first randomized, controlled, double-blind trial of intercessory prayer. This means neither the patients, nor those collecting data, knew who was being prayed for and who wasn’t. This helps to eliminate bias in the study. The study included 48 patients with psychological or rheumatoid diseases. They found that the group that was prayed for (5 out of 16 improved) and the group that was not prayed for (1 out of 16 improved) did not have significantly different outcomes.

Collipp, chairman of the pediatric department at Meadowbrook Hospital in New York, conducted the next randomized controlled, double-blind trial of prayer in 1969. He selected 18 patients with leukemia between the ages of one and 19 years old. Half of the children were prayed for daily by a protestant prayer group in Washington D.C. for 15 months. The other half were not prayed for by a specific group. (Note that you cannot account for other people that may be praying for the patients such as family members.) The outcome was survival at 15 months. 70% of the patients who were prayed for survived, while only 25% in the not-prayed for group survived. Due to the small numbers in the study, these results are not statistically significant. In other words, the results are likely due to chance.

Then, in 1988, Byrd published a famous, randomized, controlled, double-blind trial of intercessory prayer conducted on patients in the coronary care unit at San Francisco General Hospital. He took volunteer patients between August 1982 and May 1983 (393 total patients) and randomly divided them into two groups - a prayed for group and a not prayed for group. Each patient being prayed for had a group of three to seven intercessors praying for them daily. The intercessors were chosen based on being “born again Christians” who were already practicing an active Christian life with daily devotional prayer and active participation at a local church. The intercessors were all told to pray for rapid recovery, prevention of complications and death, and any other prayers they believed would be beneficial. The hospital staff, doctors, patients and Byrd, did not know which patients were being prayed for in the study. The results showed that there was no difference between the two groups in the length of stay in the hospital, in the mortality rate (death rate), or in the number of medications prescribed upon leaving the hospital. However, he found that the prayed for group had significantly less congestive heart failure, fewer cardiac arrests, less pneumonia, less use of diuretics and antibiotics, and less need for intubation and mechanical ventilation than the not prayed for group. As another way to measure outcomes, Byrd developed a scoring system that would rate a patient’s hospital course as good intermediate or bad based on adverse events that occurred during the hospital stay. The results showed 85% of the prayer group had a rating of good versus 73% in the not prayed for group. An intermediate rating was given to 1% of the prayer group and 5% of the no prayer group and a bad rating was given to 14% of the prayer group and 22% of the not prayed for group. Byrd concluded from these results that “intercessory prayer to a Judeo-Christian God has a beneficial therapeutic effect in patients admitted to a coronary care unit”.

Because the Byrd study was the only study on intercessory prayer to show clinically significant results, in 1999, a man named Harris from the Mid America Heart Institute, St. Luke’s Hospital in Kansas City, MO attempted to replicate Byrd’s findings. He hypothesized that patients who were admitted to the coronary care unit who were unknowingly and remotely prayed for by blinded intercessors, would experience fewer complications and have a shorter hospital stay than patients not receiving such prayer. Nine hundred and ninety patients were included in the study. The patients were unaware that they were involved in a study. (Note, this is a major difference from Byrd’s study in which the patients volunteered for the study.) The intercessors represented a variety of Christian backgrounds and only had to agree to the statement, “I believe in God. I believe that He is personal and is concerned with individual lives. I further believe that He is responsive to prayers for healing made on behalf of the sick”. The intercessors prayed individually for a specific patient for 28 days. Outcomes were based on a scoring system that was developed to try and rate how well or how bad the hospital course went. For example, a patient who had many complications might have a score of 10, while a patient with few complications a score of 4, and a patient with no complications would have a score of 0. Harris found that the prayed for group had a significantly lower complication score than the not prayed for group (about a 10% difference). He found no difference in length of hospital stay between the two groups. Harris concludes that, “Remote, intercessory prayer was associated with lower coronary care unit course scores. This result suggests that prayer may be an effective adjunct to standard medical care”.

The most recent study on intercessory prayer was conducted by Matthews at the University of Miami School of Medicine, Jackson Memorial Hospital outpatient hemodialysis center. The objective of the study was to explore the effects of intercessory prayer, positive visualization, and expectancy (a placebo effect) on the health and well-being of critically ill patients. 95 patients with end-stage renal disease who were receiving hemodialysis volunteered for the study. The patients were told they would be put into one of two groups. In one group, a distant, Christian prayer group would pray for them, in the other group a non-religious, positive visualization group would positively visualize the patient improving both psychologically and medically. In reality, each of these two groups of patients were split into three groups, each receiving a different treatment - either intercessory prayer, positive visualization, or nothing. The authors hypothesized that the outcomes of patients receiving intercessory prayer or positive visualization would not differ significantly from patients who received no treatment. They also hypothesized that patients expecting to receive intercessory prayer would report more positive outcomes regardless of the treatment they actually received. The results showed that patients who expected to receive intercessory prayer reported feeling significantly better than did those who expected to receive positive visualization. There was no difference in the measured medical or psychological variables between the three groups. The authors conclude, “The effects of intercessory prayer and transpersonal positive visualization cannot be distinguished from the effect of expectancy. Therefore, those two interventions do not appear to be effective treatments”.