[Publication of clinical trials in scientific journals: editorial issues].

Since the last update of the International Committee of Medical Journal Editors (ICMJE)1 recommendations, which we at REVISTA ESPAÑOLA DE CARDIOLOGÍA adopted,2-5 one of the most important contributions to this field has been the suggestion that that all clinical trials (CT) should be “registered” prior to definitive publication in biomedical journals.6-11 The ICMJE believes that from their very inception CTs need to be registered in public databases that are easily accessible both to authors, researchers, and regulatory agencies as well as the general public. The principal objective of this initiative is to improve the trials’ credibility when finally published and guarantee that the methodology employed, results, and scientific information generated should be freely available for analysis by the international scientific community.6-11 The very definition of CTs has raised controversy. A CT could be defined broadly as “a research study in human volunteers to answer specific health questions.”7 This initial definition would include observational trials and interventional trials without control groups, too. However, from the editorial point of view, and bearing in mind the implications we shall now consider, the definition proposed by the ICMJE is more pragmatic and also more acceptable.11 Thus, the CT is defined as any research project that prospectively allocates subjects to a particular intervention or comparison group to study the cause-effect relationship between a medical intervention and a health outcome.11 Such interventions include drugs, surgical procedures, and devices, as well as behavioral treatments or process-of-care changes.11 In the present article we review: a) principal biases in medical research that affect CTs; b) recommendations to improve the description of CTs in biomedical journals; c) general implications derived from the initiative to register CTs; and d) adapting REVISTA ESPAÑOLA DE CARDIOLOGÍA editorial policy. CLINICAL TRIALS AND BIAS IN RESEARCH AND PUBLICATION