Open Access Open Badges Protocol

Defining publication bias: protocol for a systematic review of highly cited articles and proposal for a new framework

Katharina Felicitas Müller12, Matthias Briel3, Alexandra D’Amario1, Jos Kleijnen4, Ana Marusic5, Elizabeth Wager6, Gerd Antes7, Erik von Elm8, Britta Lang7, Edith Motschall9, Viktoria Gloy3, Guido Schwarzer9, Doug Altman10, Joerg J Meerpohl7 and Dirk Bassler12*

Author Affiliations

1 Center for Pediatric Clinical Studies, University Children’s Hospital Tuebingen, Frondsbergstr. 23, 72070, Tuebingen, Germany

2 Department of Neonatology, University Children’s Hospital Tuebingen, Calwer-Str. 7, 72076, Tuebingen, Germany

3 Basel Institute for Clinical Epidemiology and Biostatistics, University Hospital Basel, Hebelstr. 10, CH- 4031, Basel, Switzerland

4 School for Public Health and Primary Care (CAPHRI), Maastricht University, P.O. Box 6166200 MD, Maastricht, The Netherlands

5 Department of Research in Biomedicine and Health, University of Split School of Medicine, Šoltanska 2, 21000 Split, OIB: 02879747067, Matični broj: 01315366, Žiro račun:2330003-1100071293, Split, Croatia

6 SideView, 19 Station Road, Princes Risborough, Bucks HP27 9DE, United Kingdom

7 German Cochrane Centre, Institute of Medical Biometry and Medical Informatics, University Medical Center Freiburg, Berliner Allee 29, 79110, Freiburg, Germany

8 Cochrane Switzerland, IUMSP, University Hospital Lausanne, Biopôle 2, Route de la Corniche 10, CH-1010, Lausanne, Switzerland

9 Institute of Medical Biometry and Medical Informatics, University Medical Center Freiburg, Stefan-Meier-Str. 26, 79104, Freiburg, Germany

10 Centre for Statistics in Medicine, Botnar Research Centre, Windmill Road, Oxford OX3 7LD, United Kingdom

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Systematic Reviews 2013, 2:34  doi:10.1186/2046-4053-2-34

Published: 21 May 2013



Selective publication of studies, which is commonly called publication bias, is widely recognized. Over the years a new nomenclature for other types of bias related to non-publication or distortion related to the dissemination of research findings has been developed. However, several of these different biases are often still summarized by the term 'publication bias'.


As part of the OPEN Project (To Overcome failure to Publish nEgative fiNdings) we will conduct a systematic review with the following objectives:

- To systematically review highly cited articles that focus on non-publication of studies and to present the various definitions of biases related to the dissemination of research findings contained in the articles identified.

- To develop and discuss a new framework on nomenclature of various aspects of distortion in the dissemination process that leads to public availability of research findings in an international group of experts in the context of the OPEN Project.

We will systematically search Web of Knowledge for highly cited articles that provide a definition of biases related to the dissemination of research findings. A specifically designed data extraction form will be developed and pilot-tested. Working in teams of two, we will independently extract relevant information from each eligible article.

For the development of a new framework we will construct an initial table listing different levels and different hazards en route to making research findings public. An international group of experts will iteratively review the table and reflect on its content until no new insights emerge and consensus has been reached.


Results are expected to be publicly available in mid-2013. This systematic review together with the results of other systematic reviews of the OPEN project will serve as a basis for the development of future policies and guidelines regarding the assessment and prevention of publication bias.

Publication bias; Full publication; Underreporting; New framework; The OPEN project