An increasing problem in publication ethics: Publication bias and editors' role in avoiding it.

Publication bias is defined as "the tendency on the parts of investigators, reviewers, and editors to submit or accept manuscripts for publication based on the direction or the strength of the study findings."Publication bias distorts the accumulated data in the literature, causes the over estimation of potential benefits of intervention and mantles the risks and adverse effects, and creates a barrier to assessing the clinical utility of drugs as well as evaluating the long-term safety of medical interventions. The World Medical Association, the International Committee of Medical Journals, and the Committee on Publication Ethics have conferred responsibilities and ethical obligations to editors concerning the avoidance of publication bias. Despite the explicit statements in these international documents, the editors' role in and ability to avoid publication bias is still being discussed. Unquestionably, all parties involved in clinical research have the ultimate responsibility to sustain the research integrity and validity of accumulated general knowledge. Cooperation and commitment is required at every step of a clinical trial. However, this holistic approach does not exclude effective measures to be taken at the editors' level. The editors of major medical journals concluded that one precaution that editors can take is to mandate registration of all clinical trials in a public repository as a precondition to submitting manuscripts to journals. Raising awareness regarding the value of publishing negative data for the scientific community and human health, and increasing the number of journals that are dedicated to publishing negative results or that set aside a section in their pages to do so, are positive steps editors can take to avoid publication bias.