John A. Astin, PhD; Elaine Harkness, BSc; and Edzard Ernst, MD, PhD
Purpose: To conduct a systematic review of the available
data on the efficacy of any form of “distant healing”
(prayer, mental healing, Therapeutic Touch, or spiritual
healing) as treatment for any medical condition.
Data Sources: Studies were identified by an electronic
search of the MEDLINE, PsychLIT, EMBASE, CISCOM, and
Cochrane Library databases from their inception to the
end of 1999 and by contact with researchers in the field.
Study Selection: Studies with the following features
were included: random assignment, placebo or other adequate
control, publication in peer-reviewed journals, clinical
(rather than experimental) investigations, and use of
human participants.
Data Extraction: Two investigators independently extracted
data on study design, sample size, type of intervention,
type of control, direction of effect (supporting or
refuting the hypothesis), and nature of the outcomes.
Data Synthesis: A total of 23 trials involving 2774 patients
met the inclusion criteria and were analyzed. Heterogeneity
Heterogeneity
of the studies precluded a formal meta-analysis.
Of the trials, 5 examined prayer as the distant healing
intervention, 11 assessed noncontact Therapeutic Touch,
and 7 examined other forms of distant healing. Of the 23
studies, 13 (57%) yielded statistically significant treatment
effects, 9 showed no effect over control interventions, and
showed a negative effect.
Conclusions: The methodologic limitations of several
studies make it difficult to draw definitive conclusions
about the efficacy of distant healing. However, given that
approximately 57% of trials showed a positive treatment
effect, the evidence thus far merits further study.