Better transparency needed on medical journals' competing interests, experts say

The article examined randomized clinical trials published in six general medical journals (not including PLoS Medicine but including New England Journal of Medicine (NEJM), the British Medical Journal (BMJ), The Lancet, Annals of Internal Medicine, Archives of Internal Medicine, and JAMA,) over two time periods, 1996-1997 and 2005-2006, and assessed which of the trials were supported wholly, partly, or not at all by industry. They then used the online academic citation index Web of Science to calculate an approximate impact factor for each journal for 1998 and 2007 and calculated the effect of the published RCTs on the impact factor.

The proportion of RCTs with sole industry support varied between journals. 32% of the RCTs published in the NEJM during both two-year periods had industry support whereas only 7% of the RCTs published in the BMJ in 2005-2006 had industry support. Industry-supported trials were more frequently cited than RCTs with other types of support; omitting industry-supported RCTs from impact factor calculations decreased all the approximate journal impact factors. For example, omitting all RCTs with industry or mixed support decreased the 2007 BMJ and NEJM impact factors by 1% and 15%, respectively.

Finally, the researchers asked the Editor of each journal about journal income from industry sources. For the BMJ and the Lancet, the only journals that provided this information directly, income from reprint sales was 3% and 41%, respectively, of total income in 2005-2006.

The authors conclude that "journals [should] abide by the same standards related to conflicts of interest, which they rightly require from their authors, and that the sources and the amount of income are disclosed to improve transparency." Commenting on the article, Harvey Marcovitch agrees, saying: "Journal editors have expended much time and effort in teasing out how to handle authors' and reviewers' competing interests. They need now to concentrate on their own and those of their employers."

In the accompanying editorial "Increased Responsibility and Transparency in an Era of Increased Visibility" the PLoS Medicine Editors, who have posted their own journal's income on the competing interest page of the journal, conclude that "The internet has spurred an intellectual revolution in the dissemination of medical information. Journals have thus far been accepted as one of the most trusted sources of information. It's clear, however, that in order to maintain that trust, journals and editors need to continue to consider all the pressures that can arise in publishing and put in place robust, transparent procedures for handling all the potential conflicts that can arise, whether they are those of authors, editors, or the journals themselves.''