To ensure good authorship practice.


The International Committee of Medical Journal Editors (ICMJE) recommends that authors should meet the following four criteria:

  • 1) Substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work; AND
  • 2) Drafting the article or revising it critically for important intellectual content; AND
  • 3) Final approval of the version to be published; AND
  • 4) 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 or resolved.

Acquisition of funding, collection of data, or general supervision of the research group alone are not enough to justify authorship. All persons designated as authors should qualify for authorship, and all those who qualify should be listed. Leaving out someone who does qualify as an author or not giving such a person the opportunity to qualify (e.g. by not asking for input on drafts of the article) is a breach of research integrity. See also the Amsterdam UMC Research Code. 


Always keep a record on decisions about authorship in your electronic logbook.

  • Executing researcher:Filing decisions about authorship.
  • Project leaders:Making the decisions concerning authorship timely and reasonably and updating them when needed.
  • Research assistant:N.a.
How to

The most important aspect of this guideline is to inform researchers about the requirements to become a (co-)author and the importance of clear decisions regarding authorships and the order of authors. Make sure that authorship and the intended order of authorship is clear early in your project. This prevents ambiguities at later stages and avoids large (and sometimes unreasonable) discussions. Therefore, make sure your project leader arranges the authorships per article that you are planning to write as early in the process as possible, preferably before the actual writing of the article has started.


Publications are a way to communicate scientific information to colleagues and have become a proof of academic competence. As the number of persons involved in a research project increased in recent years, it is normal that the number of persons wanting credit for their work in publications grows. However, it has to be avoided to include authors who do not meet appropriate authorship criteria [1,2]. In case someone does not qualify for authorship, but did contribute to the research or article, an acknowledgement may be in place. The specific wording of the acknowledgement should be approved by this person and some journals even ask for an informed consent of the person that is acknowledged. In order to avoid problems with regard to authorship issues, it is wise to start a discussion about envisioned authorships when planning the research and to continue to discuss this issue as the project evolves. See the Committee on Publication Ethics (COPE) ( for some of the problems that can arise around authorships. COPE also provides useful information and tools (e.g., flowcharts, checklists, cases) on the subject of authorship and for managing potential disputes.

Corresponding author

This is the person who receives the reviewers’ comments and the proofs and is responsible for sharing this information with the co-authors. In addition, the corresponding author is responsible for submitting the rebuttal(s) and final version of the article, all approved by the co-authors. The contact details of the corresponding author are printed on the article so that readers can request reprints or contact the research group. Journal editors often view this as a purely administrative role, but some authors equate it with seniority. Take the views of your co-authors at an early stage, and decide in advance who will be the corresponding author. Ideally, choose somebody whose contact details are not likely to change in the near future.

First and last authors

Generally speaking, the most sought-after position is the first, which is not surprising given the convention of referring to studies by the first-named author, e.g. ‘Smith et al. have shown that’, and that to obtain a PhD a certain number of first-author publications are needed. The first named author is therefore generally held to have made the greatest contribution to the research. In biomedical sciences also the position of the last named author is of great significance. However, views about this do seem to vary, so don’t assume that everybody feels the same way about it. Authors have often given the last place to a senior team member who contributed expertise and guidance. This can be consistent with the ICMJE criteria if this person was involved in study design, the interpretation of the data, and critically reviewed the publication.

Qualified authorship or guarantor

Should we expect a radiologist to explain the statistical methods or the statistician to interpret the x-rays? To take increasing specialization into account, the latest version of the ICMJE guidelines acknowledges that it may be unreasonable to ask each co-author to take responsibility for every aspect of the research. However, the editors felt that it is important that the integrity of the entire project is guaranteed by having at least one person responsible for every aspect of the study. The ICMJE guidelines now recommend that authors should state their specific contribution to the project: ‘authors should provide a description of what each contributed, and editors should publish that information’. Some journals publish this information, but in most cases it is for the benefit of the editor, who wants reassurance that the criteria have been fulfilled. Another advantage of qualified authorship is that is it clear to all who is responsible for what, also in case mistakes/flaws are discovered. The American Psychological Association (APA ) gives recommendations about authorship, the order of author listing, and information about negotiating about authorship. Helpful tools are provided, such as an authorship agreement and a checklist that is designed to aid contributors in deciding if they deserve authorship.

Order of authors

The ICMJE guidelines state that the order of authors, should be ‘a joint decision of the co-authors. Authors should be prepared to explain the order in which authors are listed’. They rather unhelpfully do not give guidance about the order in which authors should be listed. Wherever possible, make these decisions before starting to write the article. In some disciplinary fields (e.g., economics) the habit is to list authors alphabetically, sometimes with a note to explain that all authors made equal contributions to the study and the publication. If you do so, make sure it is clear to the editor. On the APA website, a checklist is available, designed to aid contributors in deciding the order of authorship.

Group authorship/multicentre group

Some journals permit the use of group names (e.g., The XYZ Study Group) but many require contributors to be listed (often alphabetically) and/or the writing group to be named as well. One problem with group names is that they are often miscoded on databases such as Medline. The first person in an alphabetical list of contributors sometimes becomes the first author by default, which rather defeats the object.


All contributors who do not meet the criteria for authorship should be listed in an acknowledgments section. Financial and material support should also be acknowledged. The ICMJE guidelines state: ‘All others who contributed to the work who are not authors should be named in the Acknowledgments, and what they did should be described’. All those who are listed in this way should be notified and approve the actual acknowledgement.

Ghost authors

This phrase is used in two ways. It usually refers to professional writers (often paid by commercial sponsors) whose role as an author is not acknowledged. Although such writers rarely meet ICMJE criteria, since they are not involved in the design of studies, or the collection or interpretation of data. It is important to always acknowledge their contribution (acknowledgement is not voluntary in this case), since their involvement may represent a potential conflict of interest. The same holds true for data-analyses that is performed by the sponsor.

Gift authors

People who are listed as authors but who did not make a significant contribution to the research and therefore do not fulfil the ICMJE criteria. These are often senior figures (e.g. heads of department) whose names are added to curry favor (or because it is expected). Another type of gift author is a colleague whose name is added on the understanding that he/she will do the same for you, regardless of your contribution to his/her research, but simply to swell your publication lists. Demanding or accepting an authorship for which one does not qualify (gift authorship or honorary authorship) is considered to be a breach of research integrity (Amsterdam UMC Research Code)

Number of authors

There are no rules about this. Most databases list all authors. However, remember that including large numbers of authors usually increases the time it takes to prepare, review and finalize a paper.

Professional considerations when preparing publications

Members of a research group involved in a joint research study must not prepare separate publications without the prior consent of the other members. Any proposal to use the results of a project for specific publications (e.g. a thesis) not envisaged at the start of the project should be agreed upon by the research group as a whole. Finally, it is prudent to designate at the start of a research study a senior researcher (usually the study’s PI) who will be responsible for resolving any possible conflicts regarding publication of the work.