Thursday 16 July 2009

No evidence that prayer alleviates ill health

The following is NOT a hoax. It is the summary of a recently published Cochrane review of the evidence for or against the effects of intercessory prayer for the alleviation of ill health.

In fact this is a great example of an objective and balanced analysis of the evidence for the efficacy of a treatment. Full report HERE.

Intercessory prayer for the alleviation of ill health

Leanne Roberts1, Irshad Ahmed2, Steve Hall3, Andrew Davison4

1Hertford College, Oxford, UK. 2Psychiatry, Capital Region Mental Health Center, Hartford, Connecticut, USA. 3The Deanery, Southampton, UK. 4St Stephen's House, Oxford, UK

Contact address: Leanne Roberts, Hertford College, Catte Street, Oxford, OX1 3BW, UK. (Editorial group: Cochrane Schizophrenia Group.)

Cochrane Database of Systematic Reviews, Issue 3, 2009 (Status in this issue: Edited, commented)
Copyright © 2009 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
DOI: 10.1002/14651858.CD000368.pub3
This version first published online: 15 April 2009 in Issue 2, 2009. Re-published online with edits: 8 July 2009 in Issue 3, 2009. Last assessed as up-to-date: 13 November 2008. (Help document - Dates and Statuses explained).

This record should be cited as: Roberts L, Ahmed I, Hall S, Davison A. Intercessory prayer for the alleviation of ill health. Cochrane Database of Systematic Reviews 2009, Issue 2. Art. No.: CD000368. DOI: 10.1002/14651858.CD000368.pub3.


Prayer is amongst the oldest and most widespread interventions used with the intention of alleviating illness and promoting good health. Given the significance of this response to illness for a large proportion of the world's population, there has been considerable interest in recent years in measuring the efficacy of intercessory prayer for the alleviation of ill health in a scientifically rigorous fashion. The question of whether this may contribute towards proving or disproving the existence of God is a philosophical question lying outside the scope of this review of the effects of prayer. This revised version of the review has been prepared in response to feedback and to reflect new methods in the conduct and presentation of Cochrane reviews.

To review the effects of intercessory prayer as an additional intervention for people with health problems already receiving routine health care.

Search strategy
We systematically searched ten relevant databases including MEDLINE and EMBASE (June 2007).

Selection criteria
We included any randomised trial comparing personal, focused, committed and organised intercessory prayer with those interceding holding some belief that they are praying to God or a god versus any other intervention. This prayer could be offered on behalf of anyone with health problems.

Data collection and analysis
We extracted data independently and analysed it on an intention to treat basis, where possible. We calculated, for binary data, the fixed-effect relative risk (RR), their 95% confidence intervals (CI), and the number needed to treat or harm (NNT or NNH).

Main results
Ten studies are included in this updated review (7646 patients). For the comparison of intercessory prayer plus standard care versus standard care alone, overall there was no clear effect of intercessory prayer on death, with the effect not reaching statistical significance and data being heterogeneous (6 RCTs, n=6784, random-effects RR 0.77 CI 0.51 to 1.16, I2 83%). For general clinical state there was also no significant difference between groups (5 RCTs, n=2705, RR intermediate or bad outcome 0.98 CI 0.86 to 1.11). Four studies found no effect for re-admission to Coronary Care Unit (4 RCTs, n=2644, RR 1.00 CI 0.77 to 1.30).Two other trials found intercessory prayer had no effect on re-hospitalisation (2 RCTs, n=1155, RR 0.93 CI 0.71 to 1.22).

Authors' conclusions
These findings are equivocal and, although some of the results of individual studies suggest a positive effect of intercessory prayer,the majority do not and the evidence does not support a recommendation either in favour or against the use of intercessory prayer. We are not convinced that further trials of this intervention should be undertaken and would prefer to see any resources available for such a trial used to investigate other questions in health care.

Plain language summary

Intecessory Prayer for the alleviation of ill health
Intercessory prayer is a very common intervention, used with the intention of alleviating illness and promoting good health. It is practised by many faiths and involves a person or group setting time aside to petition God (or a god) on behalf of another who is in some kind of need, often with the use of traditional devotional practices. Intercessory prayer is organised, regular, and committed. This review looks at the evidence from randomised controlled trials to assess the effects of intercessory prayer. We found 10 studies, in which more than 7000 participants were randomly allocated to either be prayed for, or not. Most of the studies show no significant differences in the health related outcomes of patients who were allocated to be prayed for and those who allocated to the other group.