Clinical Question: Does praying for patients decrease the patients’ risk of complications following heart surgery?

Setting: Inpatient (any location)

Study Design: Randomized controlled trial (single-blinded)

Allocation: Concealed

Synopsis: Intercessory prayer is the act of praying for the well-being of another in an attempt to intercede on their behalf. The researchers conducting this study enrolled 1,802 patients who were scheduled for non-emergent coronary artery bypass grafting at any one of six U.S. hospitals. Religious belief was not a criterion for entry, although approximately 80 percent of the enrolled patients listed a religious affiliation, and 85 percent of the patients were Christian. When asked, 65 percent strongly agreed with the statement, “I believe in spiritual healing.” The patients were randomly assigned, using concealed allocation, to one of three groups. Two groups received intercessory prayer on their behalf, and patients in one of these groups were specifically told they would be prayed for. The third group did not receive prayer and were told they may or may not be prayed for. The three Christian groups providing the prayers were only aware of the patients’ first names. Almost all patients believed that friends and relatives would be praying for them (96 percent).

A total of 54 percent of all patients experienced at least one complication. Complications occurred in 52.2 percent of patients who received prayers but did not know, 50.9 percent of patients who did not receive prayers but did not know, and 58.6 percent of patients who received prayers and knew (number needed to harm = 14; 95% confidence interval [CI], 7 to 96). Death rates and readmission rates were not different among the groups.

Bottom Line: Being prayed for by a Christian prayer group does not decrease a patient’s likelihood of experiencing a complication after heart surgery. A patient who knew that he or she was being prayed for was slightly more likely to have complications. The effect of self-prayer or the prayers of friends and family was not studied. (Level of Evidence: 1b)