Thursday, July 7, 2011

Prayer Study, Just the Evidence- "Long-Awaited Medical Study Questions the Power of Prayer"

Back in 2006, a scientific study on the therapeutic effects of prayer appeared in the American Heart Journal. See the full text here:

In this post, I will provide a concise summary of the study and it's conclusions. In the following posts in this series we will see if any errant fundamental assumptions are made, and attempt to determine whether or not the study means anything.

The purpose of the study was to determine whether or not receiving intercessory prayer or having the knowledge that one was being prayed for influenced recovery following coronary artery bypass graft surgery.

According to the study, the following methods were used:
"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."

The study found the following:
  • In the group that was uncertain about receiving prayer, and received prayer, 52% of the patients had complications.
  • In the group that was uncertain about receiving prayer, and did not receive prayer, 51% of the patients had complications.
  • In the group that was aware of receiving prayer, and received prayer, 59% of the patients had complications.
Another way of saying this is:
  • The patients who were prayed for and knew it fared worse than the others- 59% had complications
  • The two groups in which the patients were uncertain (one prayed for and one not) were about the same- 51% and 52% had complications.

In addition "Major events and 30-day mortality were similar across the 3 groups."

Here are the conclusions of the study:
"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."


Let me know what you think!


  1. Interesting study but it shows a complete lack of understanding of prayer on the part of the researchers. Too often we think of God as Santa Clause and prayer as our Christmas wish list. James 4:3 says – “You ask and do not receive, because you ask with wrong motives, so that you may spend it on your pleasures.” Many prayers will go unanswered because we pray selfishly.

    If we look at the record of Jesus’ prayers that we have in Scripture we see that his prayers are focused on the will of the Father (Matthew 6:10, Luke 22:42)

    This study also does not say anything about the type of prayer or who is doing the prayer. As a follower of Jesus Christ, I don’t believe that the prayer of a Hindu or a Buddhist or a Muslim would do me any good. They are pagans praying to false gods.

    It also sounds like this study treated prayer as some occult ritual. Another reason for God not to bless it.

  2. Or, James, just a chance for nonsense to be displayed as nonsense.

    Josh, I was REALLY pleased that you would post this. You have consistently been vigilant against biases and I'm glad you kept that trend in your blog. The research makes perfect sense to me. I would like to know what the standard percentage of people who have complications is, just for my own curiosity. What matters though, is that all the groups in this study had roughly the same results.

    Another research study that I thought would probably follow this trend is, 'How often does your horoscope come true?'

  3. Thanks for the post, Josh. I have a few thoughts:
    1. Correlation does not necessarily imply causation.
    2. (I agree with Austin here), I think the variance between the 51% and the 59% is not enough to make generalizations about prayer affecting presence of complications.
    3. Complications are not necessarily life threatening.
    4. I’d like to make a comment about the truth of the statement “God always answers prayer.” It is often said that God always answers with a ‘yes,’ a ‘no,’ or a ‘maybe.’ While this thinking fills Sunday school lessons nicely, it is (to borrow a phrase from XKCD) hard for this definition of “answering prayer” to be any more ambiguous. In fact, it is tautologically true (A or ~A) whether God exists or not.
    5. I would like to dispute the often used explanation for God’s apparent indifference regarding prayer that states that God only answers prayer if it is in accordance with his will. This is unbiblical, because there are clear cases of prayer (or some kind of communication with God) causing him to change his mind: see the stories of Moses and Hezekiah. It’s also not logical, because it makes no sense for us to pray about something which has a predetermined future. Finally, it is just not a good idea to stand by this argument because it is non-falsifiable and generally gives the appearance of being a cop-out.
    6. In light of the above six comments, I’d like to submit an alternative explanation for the results of the study: I believe God does not always answer prayer. There are a variety of reasons why I believe this would be the case: it may be a bad thing in the long run; it may be asked with the wrong motives; there may not be enough people praying for it; or the case presented in the prayer may not be very strong. I think most of those reasons are supported Biblically, and I’d be happy to provide more detail if there is interest.
    I know that’s a lot of text…sorry for the wordiness!

  4. I think in these studies the people praying are complete strangers to the person being prayed for. I know organizations exist for the purpose of praying for the sick and perhaps the authors of the paper contracted their prayer out to one of these organizations. Unfortunately, the full text is gated otherwise I'd read and find out :-)