What Do Prayer Studies Prove?
Should your doctor prescribe prayer as part of your treatment? According to a study of 1,134 physicians this past December by Health Care Direct Research, the majority of doctors (70 percent) believe miracles are possible today. Yet fewer than 29 percent believe that the outcomes of medical treatments are related to "supernatural forces" or "acts of God."
Studies on prayer in medicine have a way of demarcating the battle lines between saints and skeptics: Christians long for scientific proof of the efficacy of prayer. Critics, waiting for the opposite, hope to undermine religious faith. For better or worse, we have seen many attempts to measure the healing effects of intercessory prayer. The first known studies were published in 1873 by English polymath Francis Galton. He found no statistical evidence that prayer prolonged life or reduced stillbirths (though his findings would not meet today's criteria for a controlled prospective study).
More recently, various prayer experiments have caught the attention of evangelicals who are eager to show a positive connection between faith and science. One that generated particular excitement was Randolph Byrd's 1988 study, which observed 393 patients admitted to the coronary care unit of San Francisco General Hospital. About half of the patients were prayed for by "born-again Christians with daily devotional prayer and active Christian fellowship in a local church." The other half served as a control group (they received no prayer). In this study, the prayer group significantly outscored the control group.
Byrd's published report received criticism on a number of fronts, however, including possible unintentional unblinding (for example, the research assistant who knew which patients received the special prayers also collected the clinical data), and non-independent outcome variables. The latter involved the observation that most of the 6 of 29 variables in which the prayed-for group fared better were probably interrelated (meaning the 6 variables could have influenced each other).
The effect of these and other methodological problems has been to render Byrd's paper too murky to serve as evidence of God's direct activity in healing. Such controversies have been par for the course when it comes to prayer experiments: too few patients; unblinded researchers or subjects; invalid outcome measures; inappropriate statistical methods; randomization problems; and suspected outright fraud. (For a detailed analysis of many previous prayer studies, see our website IntercessoryPrayerStudies.com.)
A Celebrated Study
Three years ago, however, results from a landmark study carefully designed to put the debate to rest went public. The study received some attention at the time, but seemed to have escaped the notice of many Christians, probably because of its surprising—and for Christians, disturbing—conclusions. The Study of the Therapeutic Effects of Intercessory Prayer (STEP), conducted under the auspices of Harvard Medical School, was by far the most comprehensive of its kind. The study required 10 years and $2.4 million, and was mainly underwritten by the John Templeton Foundation, a supporter of studies that explore the intersection between religion and science.
STEP was simple and elegant, conforming to standard research norms and protocols: 1,802 patients, all admitted for coronary artery bypass graft surgery, were divided into three randomized groups. Two of the groups received prayer from committed Christians with experience praying for the sick. But only one group's members knew they were being prayed for. The result: The group whose members knew they were being prayed for did worse in terms of post-operative complications than those whose members were unsure if they were receiving prayer. The knowledge that they were being prayed for by a special group of intercessors seemed to have a negative effect on their health.