How to write a CRediT statement for medical…

Medical-research contributorship sits at an awkward intersection. The International Committee of Medical Journal Editors (ICMJE) still defines who may sign as an author of a clinical paper through its four-part test: substantial contribution to conception/design or acquisition/analysis/interpretation; drafting or critical revision; final approval; and accountability. CRediT, the Contributor Roles Taxonomy that CASRAI helped steward into NISO Z39.104-2022, sits underneath and describes what each named contributor actually did. In 2026, after another wave of journal adoption and the long-anticipated alignment with ORCID’s contributor affiliation model, a CRediT statement is no longer a discretionary nicety. It is the contributorship record of the paper.

This post walks through how to write a CRediT statement that satisfies a medical journal’s submission system in 2026, with attention to the editorial conventions of NEJM, The Lancet, JAMA, and The BMJ. It assumes you have already worked out who meets the ICMJE authorship threshold; see our medical-research authors guide for that step.

Authorship versus contributorship: not the same question

The first error we see in submissions is conflating ICMJE authorship with CRediT contributorship. ICMJE answers a binary: does this person qualify to be listed as an author and to be accountable for the work? CRediT answers a granular: of the people who are listed, who did what? A statistician who ran the analysis but did not draft or revise may not meet ICMJE criteria and is acknowledged separately; if they do meet ICMJE criteria, then their CRediT role assignment would include Formal analysis, possibly Methodology, possibly Software, and they would be named on the byline. Liz Allen and the team that originated CRediT at Wellcome Trust were explicit on this distinction; the taxonomy was designed to complement, not replace, journal authorship rules.

For medical research the second confounder is the guarantor. The BMJ has long required a named guarantor in addition to authors, and other ICMJE-following journals encourage the convention for clinical trials. The guarantor sits outside CRediT; it is closest in spirit to the Supervision role plus an accountability commitment, but it is not encoded in the taxonomy. In your CRediT statement, name the guarantor in a separate sentence; do not invent a Guarantor role.

The 14 roles in medical-research context

CRediT’s 14 roles were drafted for general research and need a brief translation when applied to clinical work. The full role definitions are normative; what follows is interpretive guidance, not a redefinition.

Conceptualization. The research question. For a registered clinical trial this is often a Principal Investigator role; for a secondary analysis it may be a junior contributor with a novel hypothesis.
Methodology. Study design, choice of endpoints, statistical-analysis-plan structure. A trial statistician contributing to the SAP earns this role even if a different person ran the final analysis.
Software. Programming for data capture (REDCap configuration counts), randomisation code, custom statistical packages, any analytic script that materially shaped results.
Validation. Reproduction of analyses, sensitivity analyses, cross-checks against an independent dataset. Often a co-author who replicates the lead analyst’s work.
Formal analysis. The statistical analysis itself.
Investigation. Recruitment, screening, consenting, clinical assessments, sample collection. Often the largest list of contributors in multi-site trials.
Resources. Provision of patient samples, biobanks, animal models, instrument time. Distinct from Funding acquisition.
Data curation. Data cleaning, harmonisation, query resolution, lock-down.
Writing – original draft. First-draft authorship of the manuscript.
Writing – review & editing. Substantive editorial revision, not copy-editing.
Visualization. Figures, including Kaplan-Meier curves, forest plots, CONSORT flow diagrams.
Supervision. Mentorship and oversight, often the senior author. A PI typically combines Supervision with Conceptualization and Funding acquisition.
Project administration. Coordination across sites, ethics submissions, sponsor liaison.
Funding acquisition. Grant-writing for the funded work.

The lead/equal/supporting qualifier

Adopted formally into NISO Z39.104 and now widely supported, the degree-of-contribution qualifier resolves a recurring source of disputes. For each role, exactly one contributor may be marked Lead, or several may be marked Equal; everyone else for that role is Supporting. In a multi-site oncology trial it is realistic to have a Lead Investigator (the coordinating PI), several Equal Investigators (site PIs), and a longer list of Supporting Investigators (sub-investigators, research nurses who meet ICMJE thresholds). The qualifier exists precisely so that the byline order does not have to encode contribution magnitude.

Writing the statement

A 2026-compliant CRediT statement is rendered as prose in the manuscript and as structured data in the submission system. Most major medical journals now extract the structured form from their submission portal directly; the prose paragraph is for the published version. Here is a worked example for a four-author RCT report:

CRediT author statement. Sarah Chen: Conceptualization (lead), Methodology (lead), Funding acquisition (lead), Supervision (lead), Writing – review & editing (equal). Marcus Okonkwo: Investigation (lead), Project administration (lead), Data curation (lead), Writing – original draft (lead). Priya Raman: Formal analysis (lead), Software (lead), Validation (lead), Visualization (lead), Writing – review & editing (equal). David Holcombe: Methodology (supporting), Investigation (supporting), Writing – review & editing (supporting), Supervision (supporting). Guarantor: Sarah Chen.

Note the explicit guarantor statement, separate from CRediT. Note also that not every role appears; Resources was inapplicable here and should be omitted rather than padded.

JATS XML output

For machine-actionable contributorship, journals serialise CRediT into JATS XML using the <role> element with the vocab="credit" attribute and the canonical role URI. The 2022 NISO version pinned the URIs at https://credit.niso.org/contributor-roles/<role-slug>/ with the qualifier expressed via specific-use="lead|equal|supporting". As an author you do not write the JATS by hand; you fill in the submission portal and the publisher’s tooling renders the XML. Where things go wrong is the round-trip: if the published HTML drops the qualifier, the JATS may also drop it and downstream Crossref deposits will be incomplete. If you care about the persistent record, check the published JATS via the publisher’s content syndication endpoint after acceptance.

Journal-specific notes

NEJM

The New England Journal of Medicine adopted CRediT in late 2023 and integrated it into its Editorial Manager workflow in 2024. NEJM’s idiosyncrasy is that it still asks separately for the prose contribution statement, then asks each author to confirm their CRediT roles, and finally requires a writing-assistance declaration that is not CRediT (it covers professional medical writers funded by sponsors). Do not list a paid medical writer who does not meet ICMJE criteria under CRediT Writing – original draft; declare them in the acknowledgements with the funding source per Good Publication Practice (GPP 2022).

The Lancet

The Lancet was an early CRediT adopter and was unusual in coupling the taxonomy to a long-standing requirement for each author to write a one-sentence prose contribution statement in their own words. Both are retained in 2026. The prose statement is what readers see in the printed acknowledgements; the structured CRediT data lives in the JATS and in Crossref. For a Lancet submission, write the structured assignment first and then have each author translate their own roles into a single readable sentence.

JAMA

JAMA and the JAMA Network journals adopted CRediT in 2022 and tied it tightly to ORCID; an author without a verified ORCID iD cannot complete the contributorship form. JAMA also asks for explicit role assignments for Statistical analysis, Obtained funding, and Administrative, technical, or material support; these are journal-specific role labels that overlap with CRediT but are tracked separately for editorial QA. If you have a Formal analysis role under CRediT you must also tick Statistical analysis on the JAMA form, otherwise the submission will not validate.

The BMJ

The BMJ adopted CRediT in 2023 and retained its long-standing guarantor requirement on top. BMJ’s submission system asks for the CRediT roles in structured form and then asks the corresponding author to identify the guarantor by name. The published article carries both: the CRediT statement as prose, and the guarantor sentence beneath it. BMJ also continues to require declarations of relationships and activities (the BMJ-specific competing interests format) which sit alongside but separately from CRediT.

Common failure modes

Three patterns recur in submissions to medical journals. First, role inflation: assigning Conceptualization to every author by reflex. CRediT is a record, not a recognition device; if a co-author did not contribute to conceptualisation, do not assign that role. Second, byline order substituting for qualifiers: a paper with five equal first-authors should mark all five as Equal on the roles they share, not just rely on a footnote saying “these authors contributed equally.” Third, missing the writing roles: every paper has someone who wrote the first draft. If your CRediT statement omits Writing – original draft, the editor will ask.

Adoption status and trajectory

As of early 2026 the CRediT adoption ledger records 70+ publishers with active CRediT support and structured submission workflows in most major medical and biomedical journals. The ICMJE has not made CRediT mandatory across its full membership, but its 2024 update to the Recommendations explicitly endorses CRediT as an acceptable mechanism for describing contributions, and several ICMJE journals require it. Outside ICMJE, the trajectory is the same: PLOS, Cell Press, Springer Nature, Wiley, Taylor & Francis, Elsevier, OUP, CUP, and a long tail of society publishers now require structured CRediT at submission.

What to do next

If you are preparing a submission, work through these in order: (1) settle the authorship list against ICMJE criteria; (2) draft the CRediT role assignment in a shared document with qualifiers; (3) have each author confirm their roles in writing before submission; (4) enter the structured data in the submission portal and copy the prose statement into the manuscript; (5) declare the guarantor and any medical writers separately. The CASRAI CRediT authors guide contains a downloadable role-assignment worksheet that has saved more co-author disputes than any other artefact we publish.

References

ICMJE, Recommendations for the Conduct, Reporting, Editing, and Publication of Scholarly Work in Medical Journals (2024 update). NISO Z39.104-2022, CRediT, Contributor Roles Taxonomy. Allen et al., Nature (2014), Publishing: Credit where credit is due. Brand et al., Learned Publishing (2015), Beyond authorship: attribution, contribution, collaboration, and credit. Holcombe, Publications (2019), Contributorship, not authorship.