Publication bias is the tendency of science and medical journals to publish studies that report a health risk or benefit (called a positive finding) rather than studies that report no health risk or benefit (called a negative finding). Researchers once reported, for example, that 80 percent of the studies sample from the Journal of the American Medical Association and the New England Journal of Medicine were positive studies. See Acad Emerg Med. 1994 May-Jun;1(3):267-71.
What this means is that studies with positive findings are more likely to be published and studies with negative findings are less likely to be published, regardless of their scientific merit.
Some causes of publication bias (from most to least innocent) include:
- Researchers don't always publish their research, especially research that shows nothing (i.e., negative findings);
- Journal editors often would rather publish novel and newsy studies in order to garner headlines and expand readership; and
- A journal may be biased against studies that don't advance its social or political agenda.
Whatever its origin, publication bias prioritizes fear over facts.