Study of the Therapeutic Effects of Intercessory Prayer (STEP) in Cardiac Bypass Patients: A Multicenter Randomized Trial of Uncertainty and Certainty of Receiving Intercessory Prayer

Herbert Benson, MD; Jeffery A. Dusek, PhD; Jane B. Sherwood, RN; Peter Lam, PhD; Charles F. Bethea, MD; William Carpenter, MDiv; Sidney Levitsky, MD; Peter C. Hill, MD; Donald W. Clem, Jr, MA; Manoj K. Jain, MD, MPH; David Drumel, MDiv; Stephen L. Kopecky, MD; Paul S. Mueller, MD; Dean Marek; Sue Rollins, RN, MPH; Patricia L. Hibberd, MD, PhD


Am Heart J. 2006;151(4):934-942. 

In This Article

Abstract and Introduction

Background: Intercessory prayer is widely believed to influence recovery from illness, but claims of benefits are not supported by well-controlled clinical trials. Prior studies have not addressed whether prayer itself or knowledge/certainty that prayer is being provided may influence outcome. We evaluated whether (1) receiving intercessory prayer or (2) being certain of receiving intercessory prayer was associated with uncomplicated recovery after coronary artery bypass graft (CABG) surgery.
Methods: Patients at 6 US hospitals were randomly assigned to 1 of 3 groups: 604 received intercessory prayer after being informed that they may or may not receive prayer; 597 did not receive intercessory prayer also after being informed that they may or may not receive prayer; and 601 received intercessory prayer after being informed they would receive prayer. Intercessory prayer was provided for 14 days, starting the night before CABG. The primary outcome was presence of any complication within 30 days of CABG. Secondary outcomes were any major event and mortality.
Results: In the 2 groups uncertain about receiving intercessory prayer, complications occurred in 52% (315/604) of patients who received intercessory prayer versus 51% (304/597) of those who did not (relative risk 1.02, 95% CI 0.92-1.15). Complications occurred in 59% (352/601) of patients certain of receiving intercessory prayer compared with the 52% (315/604) of those uncertain of receiving intercessory prayer (relative risk 1.14, 95% CI 1.02-1.28). Major events and 30-day mortality were similar across the 3 groups.
Conclusions: Intercessory prayer itself had no effect on complication-free recovery from CABG, but certainty of receiving intercessory prayer was associated with a higher incidence of complications.

More than 350000 Americans and 800000 people worldwide have coronary artery bypass graft (CABG) surgery every year.[1] Despite advances in surgical techniques, anesthesia, and postoperative care in recent years, major and minor complications occur within 30 days of CABG (1997 Society of Thoraic Surgeons Adult Cardiac Surgery Database).[2] Patients undergoing CABG often report that they are depressed,[3] and depression is associated with cardiac events[4] and mortality[5] after CABG. Many patients report using private or family prayer to cope with this stressful experience.[6]

Although the effects of private prayer on outcome after CABG are unknown, 4 trials investigated the effects of intercessory prayer in heterogeneous groups of cardiac patients. Results have been mixed—intercessory prayer was beneficial in 2 studies[7,8] and had no effect in 2 studies.[9,10] Others have criticized the studies showing benefit for using suboptimal methods of data analysis, nonstandard methods of randomization and allocation concealment, and untested outcome measures,[11,12,13,14] and those showing no effect had insufficient statistical power to reach this conclusion.[9,10] Despite these concerns, the Cochrane Collaboration[15] and others[16,17] have concluded that further scientific investigation of the possible effects of intercessory prayer is warranted.

We conducted a prospective trial to evaluate whether providing intercessory prayer or knowing that intercessory prayer would be provided influenced outcome after CABG. Patients undergoing CABG were randomized to 1 of 3 groups. Two groups did not know (ie, were uncertain) whether they would receive intercessory prayer—group 1 received intercessory prayer and group 2 did not. The third group (group 3) was informed (ie, was certain) that they would receive intercessory prayer. All patients were followed to determine whether any complication,[18] any major event,[19] or death occurred within 30 days of CABG.


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