The most conspicuous example of medical journals' dependence on the pharmaceutical industry is the substantial income from drug advertisements, but Smith believes that this is "the least corrupting form of dependence," since the ads are "there for all to see and criticize."

The much bigger problem, he argues, lies with journals publishing clinical trials funded by industry. "For a drug company a favourable trial is worth thousands of pages of advertising, which is why a company will sometimes spend upwards of a million dollars on reprints of the trial for worldwide distribution." Unlike ads, readers see these trials as the highest form of evidence, says Smith.

"Fortunately from the point of view of the companies who fund these trials--but unfortunately for the credibility of the journals who publish them--these trials rarely produce results that are unfavourable to the companies' products." Smith cites evidence from a total of 86 studies that the results of a trial are influenced by who funds it.

"The evidence is strong that companies are getting the results they want, and this is especially worrying because between two thirds and three quarters of the trials published in the major journals are funded by the industry."

Smith says that journal editors are well aware that company-funded trials bring in thousands of dollars in reprint sales, and this can put editors in a difficult position. Editors are increasingly responsible for the budgets of their journals and for producing a profit for their owners. "An editor may thus face a frighteningly stark conflict of interest: publish
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Contact: Paul Ocampo
press@plos.org
1-415-624-1224
Public Library of Science
16-May-2005