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What an author's position means in a medical article

Readers of a research paper tend to assume that the first name on the byline belongs to the subject specialist and the last one to the head of the team. This page sets out what an author's position actually indicates in biomedical research, what no international guidance defines, and the increasingly common situations in which reading the byline by rank becomes misleading. It also points to what is worth looking at instead. It concerns no individual author.

What international guidance says

The reference text in medicine is that of the International Committee of Medical Journal Editors, the ICMJE (source 1). It sets four cumulative criteria for authorship: substantial contribution to the conception or design of the work, or to the acquisition, analysis or interpretation of data; drafting the work or revising it critically for important intellectual content; approval of the published version; and agreement to be accountable for all aspects of the work. All four apply to every signatory, with no distinction by rank.

On the order of names, the ICMJE writes a single sentence:

"The criteria used to determine the order in which authors are listed on the byline may vary, and are to be decided collectively by the author group and not by editors."

In French: « Les critères retenus pour déterminer l'ordre dans lequel les auteurs sont listés dans la signature peuvent varier, et sont à décider collectivement par le groupe d'auteurs, non par les responsables de la revue. »

The World Association of Medical Editors takes the same line: "The authors themselves should decide the order in which authors are listed in an article" (source 2).

The conclusion follows plainly. No international editorial guidance makes the last author the head of the team, and none makes the first author the subject expert. What the ICMJE does define is the role of the corresponding author, "the one individual who takes primary responsibility for communication with the journal" during submission, peer review and publication. That is a correspondence and compliance role, not a scientific title.

Practice in biomedicine

A widely shared practice does exist in biomedical research. It has been described in the literature since at least 2007, and described there as an informal practice, never as a rule.

First author. As a rule of thumb, this is the person who carried out the day to day work. A bibliometric study of the division of labour in biomedical research puts it this way: "The first author is a PhD student or a postdoctoral fellow ... the last is the lab director" (source 5).

Last author. Practice associates this position with the initial design and the supervision of the study. A PLoS Biology article ties it explicitly to informal usage: "the last author often gets as much credit as the first author, because he or she is assumed to be the driving force, both intellectually and financially, behind the research" (source 3). A survey of members of academic promotion committees finds the same perception: "the last author deserved most credit for both the initial conception ... and supervision" (source 4). The term senior author is commonly used for this position, and it carries no formal definition.

Middle positions. These are the least legible. The same survey shows that the perceived credit of the first author falls as the number of signatories rises, while that of the last author holds steady (source 4). Intermediate positions carry no stable information in practice.

Corresponding author. This role has no fixed place on the byline. A bibliometric study devoted to the question concludes that "the corresponding author is most likely to appear first and then last in the byline" (source 6). Being corresponding author therefore does not mean being the senior author, and the two roles are regularly conflated.

When this reading stops being reliable

The practice described above is an indication, not proof. It degrades in several situations that have become common.

Co-first authors. A growing share of papers state that two or more people contributed equally, and carry a note to that effect. A 2026 article devoted to this point records that "co-first authorship was absent in 1990, but appeared in >30% of research articles by 2012" (source 7). The same article underlines a heavy side effect: the equal contribution statement is dropped by indexing databases and by abbreviated citations, where only the leading name survives. The visible rank can therefore contradict what the paper itself declares, and reading by position then credits one person with work the authors declared to be shared.

Alphabetical ordering of middle authors. Some bylines place the first and last authors by the usual practice, then list every intermediate name alphabetically. The study cited above notes that "alphabetical ordering of middle authors is frequent in biomedical research", and measures its rise in biomedical papers from roughly 3 per cent in 1980 to roughly 8 per cent in 2015 (source 5). Where that is the case, a name's position in the middle of the list says nothing about its contribution: it says only what letter the surname starts with. And nothing on the page tells the reader that a byline is partly alphabetical.

Consortia and collaborations with dozens of signatories. The ICMJE allows a large group to sign under a collective name, with or without individual names (source 1). The idea of a first and a last position then no longer applies: the byline names an organisation, not a hierarchy of contributions. Very long lists raise a related problem even without a group name. The same position does not weigh the same on a three author paper and on a forty author paper, and the survey cited above shows that credit given to the first author erodes as the list grows (source 4). Bibliographic databases are not always a help either: some merge the members of a collaborative group into the same list as the authors, which shifts the displayed positions.

Differences between fields. The biomedical practice is not universal. In mathematics and economics, alphabetical order throughout is common and the last position then designates no one in particular. In computer science, by contrast, a study of the careers of distinguished researchers observes that "the last author is normally the most senior researcher" (source 8). The convention exists in several fields, then, without having the same form or the same force in each.

Taken together, reading by position remains a useful landmark for a short paper, signed by a single team, with no equal contribution statement. It loses its value as soon as the list grows long, as soon as an equal contribution is declared, as soon as the middle is alphabetical, and as soon as a consortium signs.

What is worth looking at instead

An instrument designed for this has existed since 2022. The CRediT taxonomy, approved as ANSI/NISO standard Z39.104-2022, defines named contributor roles and lets a paper state who did what, by name (source 9). It distinguishes, for instance, conceptualization, "ideas; formulation or evolution of overarching research goals and aims", and supervision, "oversight and leadership responsibility for the research activity planning and execution". The difference with byline position is straightforward: a position is a rank and names no act, whereas CRediT names acts and assigns them to named people. Where a paper publishes its CRediT statements, nothing has to be inferred, it can simply be read.

For a given disease, another category of evidence says what author position never will. One can look at who coordinated the French national diagnosis and care protocol devoted to that disease, as published by the Haute Autorité de santé. One can look at which reference centres and constituent sites are designated to manage it, and who is responsible for them. One can look at who maintains a case registry, and who is principal investigator or study director of a registered trial, citing its public identifier. One can look at who coordinates a national multidisciplinary team meeting, or who sat on an expert group drafting a guidance statement.

These responsibilities differ in kind from signing a paper, for one precise reason: they are assigned by name by an institution that publishes them, so they can be checked at source, whereas an author position can only be read through an inference drawn from a practice.

One closing note for patients. Knowing who wrote a paper does not tell you who should be looking after you. For an individual situation, the doctor who follows you remains the person to speak to.

Sources

  • International Committee of Medical Journal Editors. « Recommendations for the Conduct, Reporting, Editing, and Publication of Scholarly Work in Medical Journals », section « Defining the Role of Authors and Contributors ». Free access: https://www.icmje.org/recommendations/browse/roles-and-responsibilities/defining-the-role-of-authors-and-contributors.html Accessed 17 September 2026.
  • World Association of Medical Editors. « Authorship » page, dated 10 January 2007. Free access: https://wame.org/authorship Accessed 17 September 2026.
  • Tscharntke T, Hochberg ME, Rand TA, Resh VH, Krauss J. « Author Sequence and Credit for Contributions in Multiauthored Publications ». PLoS Biology, 2007, vol. 5, e18. DOI 10.1371/journal.pbio.0050018. Free full text: https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.0050018
  • Wren JD, Kozak KZ, Johnson KR, Deakyne SJ, Schilling LM, Dellavalle RP. « The write position. A survey of perceived contributions to papers based on byline position and number of authors ». EMBO Reports, 2007, vol. 8, no. 11. DOI 10.1038/sj.embor.7401095. Free full text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2247376/
  • Mongeon P, Smith E, Joyal B, Larivière V. « The rise of the middle author: Investigating collaboration and division of labor in biomedical research using partial alphabetical authorship ». PLOS ONE, 2017, vol. 12, e0184601. DOI 10.1371/journal.pone.0184601. Free full text: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0184601
  • Mattsson P, Sundberg CJ, Laget P. « Is correspondence reflected in the author position? A bibliometric study of the relation between corresponding author and byline position ». Scientometrics, 2011, vol. 87, pp. 99 to 105. DOI 10.1007/s11192-010-0310-9. Record: https://link.springer.com/article/10.1007/s11192-010-0310-9 Paywalled, abstract only consulted.
  • Shou W. « We need to correct the wide-spread omission of equal contribution in article indexing ». PLOS Biology, 2026, vol. 24, e3003746. DOI 10.1371/journal.pbio.3003746. Free full text: https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3003746
  • Fernandes JM, Costa A, Cortez P. « Author placement in Computer Science: a study based on the careers of ACM Fellows ». Scientometrics, 2022, vol. 127, pp. 351 to 368. DOI 10.1007/s11192-021-04035-5. Record: https://link.springer.com/article/10.1007/s11192-021-04035-5 Paywalled, abstract only consulted.
  • CRediT, Contributor Roles Taxonomy. ANSI/NISO standard Z39.104-2022, approved in 2022. Free access: https://credit.niso.org/ Role pages accessed 17 September 2026.

Sources checked on 17 September 2026. Quotations are reproduced in their original language, English, and translated where the surrounding text is in French.