TIME.com Daily Rx: Do Heartfelt Prayers Help the Heart?:
"In six U.S. hospitals, researchers involved in the Study of Therapeutic Effects of Intercessory Prayer (STEP) analyzed the healing effects of third-party prayer�in which individuals pray for a stranger whom they have never met. The study volunteers�about 1,800 heart patients undergoing bypass surgery�were randomly divided into three groups: members of the first two groups were not told definitively that they would receive prayer�one of these groups received prayer, and the other did not�while members of the third group were told they would certainly be prayed for.The details:
Daily prayers by three Christian groups began on the eve of the patients� surgeries and lasted for two weeks. The results? A tad, er, disheartening."
Among the first group � who were prayed for but only told they might be � 52 per cent had post-surgical complications, compared with 51 per cent in the second group, who were not prayed for though told they might be.
In the third group, who knew they were being prayed for, 59 per cent had complications.