Authorship & contributorship


The International Committee of Medical Journal Editors Recommendations for the Conduct, Reporting, Editing, and Publication of Scholarly Work in Medical Journals (ICMJE Recommendations 2013) recommend that authorship be based on the following four criteria:

  • Substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work; AND
  • Drafting the work or revising it critically for important intellectual content; AND
  • Final approval of the version to be published; AND
  • Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

In addition to being accountable for the parts of the work he or she has done, an author should be able to identify which co-authors are responsible for specific other parts of the work. In addition, authors should have confidence in the integrity of the contributions of their co-authors.

We include only one corresponding author per article. Any further contribution details (eg, equal contribution) must be included in the contributors or acknowledgement sections at the end of the article.

The BMJ requires that all those designated as authors should meet all four ICMJE criteria for authorship, and all who meet the four criteria should be identified as authors. We recognise only natural persons as authors. These authorship criteria are intended to reserve the status of authorship for those who deserve credit and can take responsibility for the work. The criteria are not intended for use as a means to disqualify colleagues from authorship who otherwise meet authorship criteria by denying them the opportunity to meet criterion #s 2 or 3. Therefore, all individuals who meet the first criterion should have the opportunity to participate in the review, drafting, and final approval of the manuscript.

The individuals who conduct the work are responsible for identifying who meets these criteria and ideally should do so when planning the work, making modifications as appropriate as the work progresses. The corresponding author takes primary responsibility for communication with the journal during the manuscript submission, peer review, and publication process, and typically ensures that all the journal’s administrative requirements, such as providing details of authorship, ethics committee approval, clinical trial registration documentation, and gathering conflict of interest forms and statements, are properly completed, although these duties may be delegated to one or more coauthors.

When a large multi-author group has conducted the work, the group ideally should decide who will be an author before the work is started and confirm who is an author before submitting the manuscript for publication. All members of the group named as authors should meet all four criteria for authorship, including approval of the final manuscript, and they should be able to take public responsibility for the work and should have full confidence in the accuracy and integrity of the work of other group authors. They will also be expected as individuals to complete conflict-of-interest disclosure forms.

The byline of the article identifies who is directly responsible for the manuscript, and Medline lists as authors whichever names appear on the byline. If the byline includes a group name, Medline will list the names of individual group members who are authors or who are collaborators, sometimes called non-author contributors, if there is a note associated with the byline clearly stating that the individual names are elsewhere in the paper and whether those names are authors or collaborators.

At The BMJ we want authors to assure us that all authors included on a paper fulfil the criteria of authorship. In addition we want assurance that there is no one else who fulfils the criteria but has not been included as an author.

When we encounter disagreements among authors we follow guidance from the Committee on Publication Ethics (COPE)—see here and here.



The BMJ lists contributors in two ways. Firstly, we publish a list of authors' names at the beginning of the paper and, secondly, we list contributors (some of whom may not be included as authors) at the end of the paper, giving details of who did what in planning, conducting, and reporting the work. This is a good place to include contributions by patients or members of the public who have assisted as research volunteers, giving their names and specific roles. We encourage authors to fully acknowledge the contribution of patients and the public to their research where appropriate.

One or more of these contributors are listed as guarantors of the paper. The guarantor accepts full responsibility for the work and/or the conduct of the study, had access to the data, and controlled the decision to publish. See Maintaining the integrity of the scientific record.

Contributorship and guarantorship are concepts that were applied first to original research papers, and are sometimes hard to define for other articles. Each contributorship statement should make clear who has contributed what to the planning, conduct, and reporting of the work described in the article, and should identify one, or occasionally more, contributor(s) as being responsible for the overall content as guarantor(s). For articles in The BMJ that do not report original research - such as editorials, clinical reviews, and education and debate - please state who had the idea for the article, who performed the literature search, who wrote the article, and who is the guarantor (the contributor who accepts full responsibility for the finished article, had access to any data, and controlled the decision to publish). For non-research articles that include case reports such as lessons of the week, drug points, and interactive case reports, please also state who identified and/or managed the case(s).

Researchers must determine among themselves the precise nature of each person's contribution, and we encourage open discussion among all participants. See Authorship is dying; long live contributorship.

Alteration to authorship or contributorship

Any change in authors and/or contributors after initial submission must be approved by all authors. This applies to additions, deletions, change of order to the authors, or contributions being attributed differently. Any alterations must be explained to the editor. The editor may contact any of the authors and/or contributors to ascertain whether they have agreed to any alteration.

Group authorship

If there is a very large number of authors we may ask for confirmation that everyone listed met the ICMJE criteria for authorship. If they did, we may then suggest that the authors form a group whose name will appear in the article byline.

We appreciate that authors may be concerned that their work will not be properly recognised if they form a group, but this is unfounded. Medline guidance can handle group authorship and still give each individual due credit:

"When a group name for a specific consortium, committee, study group, or the like appears in an article byline, the personal names of the members of that group may be published in the article text. Such names are entered as collaborator names for the Medline citation."

Key points:

  • A Medline citation may contain an array of personal author names, group (or corporate) author names, and collaborator names.
  • Personal author names are included in Medline when the author names appear in the article byline, or are explicitly identified anywhere else in the text of the article as the authors or as the members of the writing group or writing committee for the article.
  • Group author names (also known as corporate, organization or collective names) are included in Medline when such names appear in the article byline.
  • When a group name for a specific consortium, committee, study group, or the like appears in an article byline, the personal names of the members of that group may be published in the article text. Such names are entered as collaborator names for the Medline citation.
  • Collaborator names are entered for a Medline citation only when a group (corporate) author name is present for the citation.
  • More than one group name may appear for a citation, and a group name may appear along with personal author names.
  • For articles that represent a formal guideline or practice guideline, the name of the guideline-issuing body is entered as a group name for the Medline citation, even if that name does not appear in the article byline.

What this means for The BMJ's authors

a) if authors form a group for the article's main byline they will also be listed individually:

  • As collaborators in the article's Medline/PubMed record;
  • As authors in a group authorship statement at the end of the article on; and
  • As contributors in the contributorship statement at the end of the article on

b) however, for The BMJ's research articles with many authors, where those authors do not opt to form a group, we will not be able to publish a BMJ pico in the print issue of The BMJ. Such research articles will be for online only ( publication only.

Here's a research article in The BMJ with group authorship as it appeared on Medline, with all collaborators clearly listed as individuals:

And here's how the individual authors for that article were listed on

1. What appeared at the top of the article and was dowloadable to citation manager:

Effect of a collector bag for measurement of postpartum blood loss after vaginal delivery: cluster randomised trial in 13 European countries. Wei-Hong Zhang, Catherine Deneux-Tharaux, Peter Brocklehurst, Edmund Juszczak, Matthew Joslin, Sophie Alexander, on behalf of the EUPHRATES Group. BMJ 2010;340:c293, doi: 10.1136/bmj.c293 (Published 1 February 2010)

2. What appeared at the end of the article in an authorship statement:

The following are members of EUPHRATES (EUropean Project on obstetric Haemorrhage, Reduction, Attitudes, Trial and Early warning System): Sophie Alexander (project leader, Belgium), Diogo Ayres-de-Campos (Portugal), Istvan Berbik (Hungary), Marie-Hélène Bouvier-Colle (France), Gérard Bréart (France), Peter Brocklehurst (UK), Vicenç Cararach (Spain), Anna Maria Marconi (Italy), Catherine Deneux-Tharaux (France), Risto Erkkola (Finland), Mathias Klein (Austria), Jens Langhoff-Roos (Denmark), Alison Macfarlane (UK), Walter Prendiville (Republic of Ireland), Jos van Roosmalen (Netherlands), Babill Stray-Pedersen (Norway), Carolyn Troeger (Switzerland), Clare Winter (UK), and Wei-Hong Zhang (Belgium). Also see web extra for a list of people who helped in each country.

3. What appeared at the end of the article in the contributorship statement:

Contributors: W-HZ designed data collection tools, monitored data collection for the whole trial, wrote the statistical analysis plan, cleaned and analysed the data, and drafted and revised the paper. She is guarantor. CD-T implemented the trial in France, analysed the data, and drafted and revised the paper. PB analysed the data and drafted and revised the paper. EJ wrote the statistical analysis plan, monitored data collection for the whole trial, and revised the draft paper. MJ designed data collection tools,, monitored data collection for the whole trial, and revised the draft paper. SA initiated the collaborative project, designed data collection tools, implemented the trial for the all countries, monitored data collection for the whole trial, analysed the data, and drafted and revised the paper. All members of EUPHRATES designed the trial. Diogo Ayres-de-Campos, Istvan Berbik, Marie-Hélène Bouvier-Colle, Vicenç Cararach, Risto Erkkola, Mathias Klein, Walter Prendiville, Jos van Roosmalen, Babill Stray-Pedersen, and Carolyn Troeger implemented the trial in, respectively, Portugal, Hungary, France, Spain, Finland, Austria, Republic of Ireland, Netherlands, Norway, and Switzerland, and revised the draft paper. Gérard Bréart analysed the data and revised the draft paper. Alison Macfarlane and Clare Winter revised the draft paper.