Such a practice would violate the guidelines of the Pharmaceutical Research and Manufacturers of America, or PhRMA, the prescription drug industry's trade group, on the communication of clinical trial results. According to the PhRMA guidelines, anyone involved in analyzing, interpreting or writing up clinical trial data "should be recognized appropriately in resulting publications."

It is not known what proportion of papers submitted to medical journals are ghostwritten. But of the 70 to 80 manuscripts her journal receives each month, two to four present suspiciously glowing reports of a drug's benefits or excessively critical appraisals of its competitors, says Martha Gerrity, co-editor of the Journal of General Internal Medicine. Many are reviews of previous research and not new clinical trial findings, she says.

"What is surprising is the growth in the number of manuscripts where the pharmaceutical industry is trying to manipulate the medical literature," says Gerrity, of the Oregon Health & Science University in Portland. Her journal posted a commentary online about one such article last month.

Adriane Fugh-Berman, an adjunct associate professor of physiology and biophysics at Georgetown University, described how a British medical education company, on a drugmaker's behalf, asked her about a year ago to write a piece about interactions between herbs and warfarin, a generic anticoagulant, or blood thinner. When the company sent her a one-sided draft under her byline, Fugh-Berman says, she declined to get involved.

Months later, slightly reworked and under a different byline, the paper was submitted to the Journal of General Internal Medicine The article came full circle when the journal's editors asked Fugh-Berman, known for her expertise on herbal supplements, to review it. When she told the editors of the paper's history, they rejected it.

"Diligence of medical editors and reviewers will continue to be the first line of defense against the sullying of the medical literature by biased 'reviews' whose motivation is commercial, not scientific," Gerrity and co-editor William Tierney wrote in an editorial accompanying Fugh-Berman's commentary.

In response to the warfarin article incident, the World Association of Medical Editors posted a statement online calling the ghostwriting of manuscripts "dishonest and unacceptable."

Catherine DeAngelis, editor of The Journal of the American Medical Association, says, "This has been going on forever." Before she became an editor, DeAngelis says, she got a call a month asking her to put her name on a paper she didn't write, a practice she describes as "manipulation by for-profits to alter what's in the (medical) literature so they could sell their products."

Gerrity's journal doesn't name names, but Fugh-Berman says the education company approached her on behalf of AstraZeneca, which was seeking Food and Drug Administration approval of Exanta, a new anticoagulant. The FDA eventually rejected Exanta.

"The manuscript will be completely objective, and there will be no promotion of any drug," an education company employee said in an introductory e-mail to Fugh-Berman. "It is intended to highlight the inadequacies of current anticoagulation treatment and practices."

Valerie Siddall, AstraZeneca's head of global publications, says the drugmaker "made no secret of the fact that we actually are very interested and very active in anticoagulants as an area of research."

But, she says, the medical education company made "a really awful error" in presenting Fugh-Berman with a completed manuscript before getting her input.

Siddall says the named author of the version submitted to the internal medicine journal "had full editorial control about what went in the paper."