Discredited prayer studies:

While personal prayer provides comfort and solace, my particular area of investigative interest
is the quality and integrity of the published scientific studies on the effects of prayer.

The famous 2001 study (J Reprod Med 2001 Sep;46(9):781-787) purporting to demonstrate that
distant intercessory prayer positively influences the success rate of in-vitro fertilization
has been exposed as an apparent fraud.  See here and here.

The famous 1998 study (West J Med 1998 Dec;169(6):356-63) purporting to demonstrate that
distant intercessory prayer positively influences the course of AIDS
turns out to have been fudged as well.  See here and here.

Prayer-Related Articles  by Gary P. Posner, M.D.

"Study Yields No Evidence for Medical Efficacy of Distant Intercessory Prayer: A Follow-up Commentary" (a critique of this study by Dr. Dale Matthews),  The Scientific Review of Alternative Medicine , Winter 2002  [My preliminary article, "An Examination of the Media Coverage of a Prayer Study-in-Progress," was published in The Scientific Review of Alternative Medicine ,  Fall/Winter 1998.]

 "Hardly a Prayer on ABC's 20/20 Downtown" (brief commentary about my appearance during the 8/13/01 20/20 Downtown  report on "The Power of Prayer"), Skeptical Inquirer,  Nov/Dec 2001

"Another controversial effort to establish the medical efficacy of intercessory prayer" (a critique of the Harris group's Archives of Internal Medicine  study),  The Scientific Review of Alternative Medicine ,  Spring/Summer 2000

"Has science proven the 'divine' health benefits of religion?" (a critique, written at the request of the Secular Web, of a USA Today  article, Aug. 1998)

"Examining an Unsolved Mysteries  Report of a 'Miraculous' Cure" (of a Florida woman who claimed to have been diagnosed with "breast cancer"), Skeptical Inquirer,  Sept/Oct 1995

Book cover  "Medical Practice Enters a New Age" (review of Healing Words: The
 Power of Prayer and the Practice of Medicine
  by Dr. Larry Dossey),
 Skeptical Inquirer,  Summer 1994

"NBC's Cynically Skewed Reporting on the Power of Prayer," Free Inquiry,  Summer 1994

"God in the CCU?" (critique of Dr. Randolph Byrd's 1988 study on intercessory prayer), Free Inquiry,  Spring 1990 (also posted here)

"A Case of Immaculate Abortion?" (evaluation of a gynecologist's miraculous medical claim), Free Inquiry,  Summer 1988

"Nonhealing a Nonexistent Tumor" (investigation of TV faith-healer Peter Popoff's claimed cure of a Tampa girl), Free Inquiry,  Winter 1986-87

Medical Consultant for The Faith Healers  by James Randi James Randi (Prometheus Books, 1987)