In 2002, a large trial showed conclusively that HRT did not reduce cardiovascular disease, and increased the risk of breast cancer. Yet ghostwritten articles published after this date downplayed the 2002 study, suggesting that there was no consensus on Prempro's breast cancer risk.
Pfizer says Fugh-Berman's study fails to acknowledge significant changes undertaken by drug companies to strengthen disclosure in connection with medical literature.
The criticism of ghostwriting is one of several issues that have put scientific journals on the defensive. Even journal editors acknowledge they have sometimes done a poor job of detecting when articles cherry-pick favorable data to promote a particular drug or treatment. Some health insurers have stopped taking what they read in the journals on faith and are employing analysts to scrutinize articles for negative data that are buried.
An analysis presented at a medical-journal conference in September 2005 found that just 10 percent of articles on studies sponsored by the drug industry that appeared in top medical journals disclosed help from a medical writer. Often the help isn't disclosed. An informal poll of 71 free-lance medical writers by the American Medical Writers Association found that 80 percent had written at least one manuscript that didn't mention their contributions.
A 1999 document that turned up in a lawsuit describes Pfizer's publications strategy for its antidepressant Zoloft. The document, prepared by a unit of ad giant WPP Group, includes 81 different articles proposed for journals. They would promote the drug's use in conditions from panic disorder to pedophilia.
AstraZeneca has repeatedly denied its frequent use of ghostwriters in scientific studies of dozens of its drugs. Despite several convictions, the company still publicly states that "AstraZeneca does not support the practice of ghostwriting" and always discloses any support it gives to academic authors.
John Farrar, a pain expert at the University of Pennsylvania, says he once turned down a company's offer to give him a ghostwritten draft about a study on which he had worked. "They said, 'That's unusual,' " Dr. Farrar recalls. He wanted to write the manuscript himself because "you can put your spin on it. ... The way it is written -- the way it's structured -- is yours."