Study focuses on publication bias in journals

Requirements that clinical trials be registered in databases may give physicians a clearer picture of a drug's efficacy, but some argue that more action is needed.

By Susan J. Landers, AMNews staff. Feb. 18, 2008.

Washington -- Physicians trying to keep up with the latest journal articles have their work cut out for them in more ways than one. First, there is the massive number of articles to read. Second, the possibility of publication bias must be considered. Both pose significant challenges when weighing the risks and benefits of therapeutic treatments.

"Evidence shows that even if physicians were to do their darndest to keep up with all of the literature ... and even if they were just keeping up with the quality journals, they would still have to read 19 articles a day, 365 days a year. They just can't do it," said Kay Dickersin, PhD, professor of epidemiology and director of the Center for Clinical Trials at Johns Hopkins University's Bloomberg School of Public Health in Baltimore.

Plus, a study in the Jan. 17 New England Journal of Medicine, which quantified the previously recognized problem of publication bias, shows that it can be difficult to gather all the information needed to properly assess a medication by reviewing journal articles, since negative data are not always accessible.

The researchers determined that 94% of published studies on 12 antidepressants were positive. In contrast, an FDA analysis found that only 51% of all studies on the antidepressants, including those that were not published, were positive. "Selective reporting of clinical trial results may have adverse consequences for researchers, study participants, health care professionals and patients," the authors concluded.