Which citation style is more common in medical school, Vancouver or APA?

Clinical courses and most biomedical journals teach a Vancouver-family numbered style. Behavioral-science, nursing, and some public-health courses in the same school often require APA 7. Ask the syllabus; do not assume the MD program and the nursing program share a handbook.

Can I use APA for a clinical research paper?

Only if the target journal or your committee says so. Most clinical journals follow ICMJE and want numbered Vancouver-family references. A nursing or health-psychology journal is the usual case where APA 7 is required instead — Journal of Nursing Education names the APA 7th edition and an alphabetical list.

Is Vancouver the same as AMA or IEEE?

No. They share a numbered in-text idea and almost no punctuation you can copy. AMA 11 is the JAMA Network house style (superscripts; first 3 authors plus et al. when there are more than 6). IEEE uses [1] on the line and engineering abbreviations. Vancouver is ICMJE policy plus NLM bibliographic recipes.

Do Vancouver citations use parentheses, brackets, or superscripts?

ICMJE's published sentence is Arabic numerals in parentheses: (1). BMJ Author Hub then asks for square brackets or superscripts, and reserves parentheses for in-line lists. Check the Instructions for Authors and stay consistent. Do not mix marks in one manuscript.

How do Vancouver and APA use et al. differently?

Vancouver / NLM samples: in the reference list, print six names, then et al. APA 7: in every in-text citation, three or more names become first-plus-et-al.; in the reference list, print up to 20 names before an ellipsis. A journal may tighten Vancouver further — BMJ Author Hub asks for the first three names, then et al.

Do both styles require a DOI?

If the work has a DOI, include it in both. NLM writes doi: 10.1136/bmj.a2752 and may add PMID/PMCID. APA 7 writes https://doi.org/10.1136/bmj.a2752 and does not put a period after the URL. Do not add a retrieval date just because the article is online.

Does Vancouver require issue numbers?

Not always. NLM sample 1 shows the full form with month and issue (2002 Jul 25;347(4):284-7) and an optional form that omits them when pagination runs through the volume (2002;347:284-7). If the journal's own samples include the issue, include it.

How do I check that a Vancouver number does not point at a retracted paper?

ICMJE says you are responsible for verifying references in PubMed or the original source, and that PubMed is the authority for MEDLINE retractions. Search PubMed for Retracted publication [pt], or use PubMed's retracted-publication list, before you freeze the numbered list.

Can I cite ChatGPT or another AI tool as a source?

Not as a primary source under ICMJE: "Referencing AI-generated material as the primary source is not acceptable." The January 2026 Recommendations also say chatbots cannot be authors, and that Methods must name the tool, version, and prompts if AI conducted part of the study. APA 7 treats a chat as a software/tool citation or, when the output is unrecoverable, as a personal communication.

Vancouver vs APA Citation Styles (ICMJE / APA 7) [2026]

Quick Answer: Vancouver vs APA

Use Vancouver when the journal says ICMJE, Uniform Requirements, NLM, or Vancouver — the default for most international biomedical journals. Use APA 7 when the course or journal is in psychology, many nursing and allied-health programs, or another behavioral field. Do not treat Vancouver as IEEE square brackets, and do not treat it as AMA: JAMA Network journals want the AMA Manual of Style, 11th edition. If the real comparison is two numbered medical styles, use AMA vs Vancouver.

Same claim, two official systems

Vancouver in text (ICMJE):

Identify references in text, tables, and legends by Arabic numerals in parentheses: (1) or (1-3).

Vancouver later reuse:

The same source keeps the same number: (1) again, not a new number.

APA 7 parenthetical (§8.11):

(Grady et al., 2019)

APA 7 narrative (§8.11):

Grady et al. (2019)

Vancouver journal pattern (NLM sample 1):

Halpern SD, Ubel PA, Caplan AL. Solid-organ transplantation in HIV-infected patients. N Engl J Med. 2002 Jul 25;347(4):284-7.

APA 7 journal pattern (Style Center §10.1):

Grady, J. S., Her, M., Moreno, G., Perez, C., & Yelinek, J. (2019). Emotions in storybooks: A comparison of storybooks that represent ethnic and racial groups in the United States. Psychology of Popular Media Culture, 8(3), 207–217. https://doi.org/10.1037/ppm0000185

Vancouver (ICMJE / NLM)

A family, not one paid student handbook
ICMJE in-text: Arabic numerals in parentheses (1)
Reference list in order of first citation
Surname then initials, no periods: Halpern SD
MEDLINE journal abbreviations: N Engl J Med
NLM samples: first 6 authors, then et al.

APA 7th edition (2020)

One manual: Publication Manual, 7th ed.
Author–date citations: (Grady et al., 2019)
Reference list A-to-Z by author, unnumbered
Surname, initials with periods: Grady, J. S.
Full journal titles in title case, italic
List up to 20 authors before an ellipsis

Current Manuals: ICMJE January 2026 / NLM vs APA 7

Vancouver is not a competing 7th-edition book. The International Committee of Medical Journal Editors publishes free Recommendations (updated January 2026, including a new Section V on AI in publishing). Those recommendations send reference format to the National Library of Medicine: the Samples of Formatted References page (last reviewed 2 June 2026) and Citing Medicine, 2nd edition (2007). APA 7th edition, published in 2020, is still the current Publication Manual in 2026; in-text rules sit in §§8.10–8.36 and reference examples in Chapter 10.

Current authorities behind Vancouver and APA citations
Element	Vancouver	APA 7
Governing document	ICMJE Recommendations (January 2026) + NLM Citing Medicine	Publication Manual of the American Psychological Association, 7th ed. (2020)
Cost	Free online	Paid manual; APA Style website summarizes the citation rules
In-text system	One numbered system (mark varies by journal)	One author–date system
End list title	References, numbered 1, 2, 3 in citation order	References, unnumbered, alphabetical
Official start pages	ICMJE manuscript preparation; NLM sample references	APA Style author–date; journal article examples

How the official documents describe their own systems

ICMJE Recommendations

References should be numbered consecutively in the order in which they are first mentioned in the text. Identify references in text, tables, and legends by Arabic numerals in parentheses.

ICMJE, on journal titles

The titles of journals should be abbreviated according to the style used for MEDLINE.

ICMJE, on format

References should follow the standards summarized in the NLM's Sample References webpage and detailed in the NLM's Citing Medicine, 2nd edition.

NLM Samples of Formatted References

The recommended style for references is based on the National Information Standards Organization NISO Z39.29-2005 (R2010) Bibliographic References as adapted by the National Library of Medicine for its databases.

APA Style author–date page

Use the author–date citation system to cite references in the text in APA Style. In this system, each work used in a paper has two parts: an in-text citation and a corresponding reference list entry.

Those sentences come from the ICMJE preparing-a-manuscript page, the NLM sample-references page, and the APA Style author–date page. They are the shortest accurate definition of the Vancouver vs APA choice: a reusable number versus a name-plus-year that points to an alphabetical list.

What Is the Difference Between Vancouver and APA?

The deepest difference is what each style wants the reader to notice. Vancouver hides the author and year so a methods paragraph can carry many sources without breaking the sentence. APA puts the year next to the name so a psychology, nursing, or health-behavior reader can judge how recent the evidence is. That is why a clinical trial report almost never uses (Author, Year), and why a methods-heavy psychology paper almost never wants (1) in every sentence.

Vancouver is also not AMA and not IEEE, even though all three number sources. AMA is one house style for the JAMA Network, with superscripts and a different author cutoff — see AMA vs Vancouver. IEEE uses square brackets on the line and engineering journal abbreviations — see IEEE vs APA. If your course is clinical rather than electrical, stay on this page.

The same NLM sample article in both styles

Vancouver in text:

Halpern and colleagues (1) argue that asymptomatic HIV-positive patients should be considered for transplantation; later notes reuse (1).

Vancouver reference (NLM sample 1, standard journal article):

1. Halpern SD, Ubel PA, Caplan AL. Solid-organ transplantation in HIV-infected patients. N Engl J Med. 2002 Jul 25;347(4):284-7.

APA 7 in text:

Halpern et al. (2002) argue that asymptomatic HIV-positive patients should be considered for transplantation (Halpern et al., 2002, p. 284).

APA 7 reference (same paper, APA §10.1):

Halpern, S. D., Ubel, P. A., & Caplan, A. L. (2002). Solid-organ transplantation in HIV-infected patients. The New England Journal of Medicine, 347(4), 284–287. https://doi.org/10.1056/NEJMsb020632

In-Text Citations

Vancouver: a number, reused

ICMJE's own sentence is parentheses: (1). Many journals then change only the mark. The BMJ family, on the Author Hub formatting page, asks for square brackets or superscripts in the text and reserves parentheses for in-line lists. The Lancet and NEJM print superscripts after punctuation. Some schools teach square brackets and still call the result Vancouver. The number is assigned at first mention and reused for the rest of the paper. References cited only in a table or figure legend take their number from the first mention of that table or figure in the text. Page locators are uncommon in Vancouver running text; if a journal wants a page, it will say so.

Official Vancouver in-text patterns

ICMJE, tables and figures

References cited only in tables or figure legends should be numbered in accordance with the sequence established by the first identification in the text of the particular table or figure.

ICMJE, electronic references

Journals vary on whether they ask authors to cite electronic references within parentheses in the text or in numbered references following the text. Authors should consult with the journal to which they plan to submit their work.

BMJ Author Hub, in-text marks

References cited in the text should be presented in square brackets [6] or superscripts. Parentheses (6) should be used for in-line lists

Several sources (ICMJE parentheses):

Two trials and one review support the finding (1-3). Non-consecutive numbers are written (1,3,5).

Same sources as superscripts (common house style, not ICMJE text):

Two trials and one review support the finding.^1-3

APA 7: author–date

APA 7 has two in-text shapes, both covered in §8.11. A parenthetical citation puts author and year in parentheses. A narrative citation puts the name in the sentence and the year in parentheses after it. For one or two authors, include every name in every citation. For three or more authors, APA uses the first surname plus et al. from the first citation (§8.17). The year in the citation is only the year, even when the reference list has a month and day. A specific page or section is added after a comma: (Halpern et al., 2002, p. 284).

Official APA 7 journal example (Style Center, §10.1)

Parenthetical:

(Grady et al., 2019)

Narrative:

Grady et al. (2019)

Two authors, parenthetical vs narrative:

(Halpern & Ubel, 2002) would apply only if those were the sole authors; Halpern, Ubel, and Caplan become Halpern et al.

APA Style, basic principles:

Each work cited must appear in the reference list, and each work in the reference list must be cited in the text (or in a table, figure, footnote, or appendix).

In-text Vancouver vs APA at a glance
Feature	Vancouver	APA 7
Mark in the sentence	(1), [1], or ¹	(Author, Year)
Official ICMJE mark	Arabic numerals in parentheses	Not applicable
One source	(1)	(Halpern et al., 2002)
Several sources	(1-3) or (1,3,5)	(Grady et al., 2019; Halpern et al., 2002)
Same source again	Reuse (1)	Repeat the author–date
Page or part	Rare in running text	(Halpern et al., 2002, p. 284)
Author visible	Only if you write the name	Always

Reference Lists

Vancouver numbers the list in the order sources first appear. Initials follow the surname and take no periods: Halpern SD, Ubel PA. Article titles are sentence case without quotation marks. Journal titles are MEDLINE abbreviations from the NLM Catalog journals list. The ICMJE/NLM sample rule is: list the first six authors, then et al. NLM databases themselves now list every author; your manuscript still follows the sample-page cutoff unless the journal says otherwise. The BMJ family is stricter: the Author Hub lists the first three names, then et al.

APA 7 titles the list References, sorts it alphabetically, and does not number it. Surnames come first, with a comma and spaced initials: Halpern, S. D. Article titles are sentence case without quotation marks; periodical names are italic title case and are not abbreviated. APA lists up to 20 authors before an ellipsis plus the final name. A DOI is written as a https://doi.org/ URL and does not take a final period.

Official author-count examples

NLM sample 1, more than six authors

List the first six authors, followed by et al. If there are more than six authors, list the first six authors, followed by et al. (Note: NLM now lists all authors.):

NLM official 7+ author sample:

Rose ME, Huerbin MB, Melick J, Marion DW, Palmer AM, Schiding JK, et al. Regulation of interstitial excitatory amino acid concentrations after cortical contusion injury. Brain Res. 2002;935(1-2):40-6.

BMJ Author Hub, author cutoff

The first three authors are listed by last name and initials, with additional authors acknowledged by the use of 'et al' if applicable.

BMJ Author Hub print-journal sample:

Koziol-Mclain J, Brand D, Morgan D, et al. Measuring injury risk factors: question reliability in a statewide sample. Inj Prev 2000;6:148–50.

APA 7 for the same cutoff idea:

Seven authors are still listed in full in APA 7. The ellipsis appears only at 21 or more names: first 19, then …, then the last author.

Reference-list mechanics
Element	Vancouver (NLM samples)	APA 7
Order	Citation order	Alphabetical by author
Numbering	1, 2, 3…	None
Author name	Halpern SD	Halpern, S. D.
Two authors	Halpern SD, Ubel PA	Halpern, S. D., & Ubel, P. A.
Many authors	First 6, then et al.	List 20; then ellipsis plus last
Article title	Sentence case, no quotes	Sentence case, no quotes
Journal title	MEDLINE abbreviation, usually roman	Full name, italic title case
Volume / issue	347(4):284-7	347(4), 284–287
Issue number	Optional if pagination is continuous through the volume	Include when the journal uses issues
DOI	doi: 10.1136/bmj.a2752	https://doi.org/10.1136/bmj.a2752

Journal Articles

Journal articles are the default research source in both styles, but the punctuation is not a find-and-replace. NLM wants the abbreviated journal title, year, volume, optional issue, and a hyphenated page span that may collapse digits (284-7). APA 7 §10.1 wants the full journal title, italic volume, roman issue in parentheses, an en dash in the page range, and a DOI URL. NLM also shows an optional form that drops month and issue when the volume paginates continuously.

Official NLM journal samples

Standard journal article (NLM sample 1):

Halpern SD, Ubel PA, Caplan AL. Solid-organ transplantation in HIV-infected patients. N Engl J Med. 2002 Jul 25;347(4):284-7.

Optional continuous-pagination form (same sample):

Halpern SD, Ubel PA, Caplan AL. Solid-organ transplantation in HIV-infected patients. N Engl J Med. 2002;347:284-7.

Organization as author (NLM sample 2):

Diabetes Prevention Program Research Group. Hypertension, insulin, and proinsulin in participants with impaired glucose tolerance. Hypertension. 2002;40(5):679-86.

Article with a DOI (NLM sample 36 optional MEDLINE form):

Zhang M, Holman CD, Price SD, Sanfilippo FM, Preen DB, Bulsara MK. Comorbidity and repeat admission to hospital for adverse drug reactions in older adults: retrospective cohort study. BMJ. 2009 Jan 7;338:a2752. doi: 10.1136/bmj.a2752. PubMed PMID: 19129307; PubMed Central PMCID: PMC2615549.

APA 7 official journal example plus the same Halpern paper

APA §10.1 (Grady et al., 2019, Style Center):

The same Halpern paper in APA 7:

Books and Chapters

NLM still prints the place of publication. APA 7 dropped publisher location — the Style Center book page, as reprinted by Alamo Colleges, says "Do not include the publisher location." Book titles are italic in APA and usually roman in Vancouver samples. Both styles put the edition after the title. Use the official NLM book and chapter samples rather than inventing a textbook citation.

Official book and chapter examples

Vancouver / NLM sample 19 (personal authors):

Murray PR, Rosenthal KS, Kobayashi GS, Pfaller MA. Medical microbiology. 4th ed. St. Louis: Mosby; 2002.

Vancouver / NLM sample 23 (chapter):

Meltzer PS, Kallioniemi A, Trent JM. Chromosome alterations in human solid tumors. In: Vogelstein B, Kinzler KW, editors. The genetic basis of human cancer. New York: McGraw-Hill; 2002. p. 93-113.

APA 7 official book example (Style Center, §10.2):

Jackson, L. M. (2019). The psychology of prejudice: From attitudes to social action (2nd ed.). American Psychological Association. https://doi.org/10.1037/0000168-000

DOIs, Databases, and Missing Pieces

If a journal article has a DOI, include it in both styles. NLM samples write doi: 10.1136/bmj.a2752 with a space after the colon and may also add PubMed PMID and PMCID. APA 7 writes the DOI as https://doi.org/10.1136/bmj.a2752 and stops there — no "Retrieved from," no access date, no period after the URL. A library database is not a second publisher in APA 7 when the article has a DOI; cite the article, not the EBSCO or Ovid platform. Vancouver internet articles that lack a DOI follow NLM sample 36, with [Internet], a cited date, and Available from: URL. Verify MEDLINE abbreviations in the NLM Catalog, not by guessing.

DOI and no-author official samples

Vancouver DOI (NLM wording):

doi: 10.1136/bmj.a2752

APA 7 DOI:

https://doi.org/10.1136/bmj.a2752

Vancouver no-author official sample (NLM sample 4):

21st century heart solution may have a sting in the tail. BMJ. 2002;325(7357):184.

APA 7 no-author pattern (sentence-case title first):

21st century heart solution may have a sting in the tail. (2002). BMJ, 325(7357), 184.

Preprints, Retractions, Unpublished Work, and AI

ICMJE's January 2026 update added a new Section V on AI in publishing and restated the citation ban: do not treat a chatbot as the primary source. Authors who used AI to conduct the study must describe the tool, version, and prompts in Methods. Chatbots cannot be authors. Both styles keep unrecoverable emails and conversations out of the reference list. ICMJE allows a personal communication in parentheses in the text only when it is essential and the source has confirmed accuracy in writing. APA 7 §8.9 does the same: name, "personal communication," and exact date in the text only. For accepted-but-unpublished articles, ICMJE still allows "in press" or "forthcoming" in the reference list; APA 7 uses "in press" as the date. When you cite a preprint, ICMJE requires the citation to say so. For the APA interview and email rules, see how to cite personal communications. For the APA, MLA, and CMOS AI rules, see how to cite AI.

Official ICMJE wording on sources you cannot treat as ordinary papers

ICMJE, unpublished and personal communication

References to papers accepted but not yet published should be designated as "in press" or "forthcoming." Information from manuscripts submitted but not accepted should be cited in the text as "unpublished observations" with written permission from the source.

ICMJE, personal communication

Avoid citing a "personal communication" unless it provides essential information not available from a public source, in which case the name of the person and date of communication should be cited in parentheses in the text.

ICMJE, generative AI

Referencing AI-generated material as the primary source is not acceptable.

ICMJE, retractions

For articles published in journals indexed in MEDLINE, the ICMJE considers PubMed the authoritative source for information about retractions.

ICMJE, preprints

When preprints are cited, the citation should clearly indicate that the reference is a preprint (also see Section III.D.3).

NLM official preprint sample (item 34):

Alvarez R. Near optimal neural network estimator for spectral x-ray photon counting data with pileup. arXiv:1702.01006v1 [Preprint]. 2017 [cited 2017 Feb 9]: [11 p.]. Available from: https://arxiv.org/abs/1702.01006

ICMJE also tells authors to verify every reference in PubMed or the original document, and to search PubMed for Retracted publication [pt] (or use PubMed's retracted-publication list) so a numbered list does not silently point at a withdrawn paper. Published articles should include the persistent identifier of any dataset they used — see how to use DOIs for the URL form.

When to Use Vancouver vs APA

Start with the venue, then the research question. A department habit is evidence, not a rule. Most medical schools teach Vancouver for clinical research and APA for behavioral-science or nursing courses in the same building. Clinical practice guidelines, case reports, and medical systematic reviews usually follow a Vancouver-family numbered style. Psychological and health-behavior meta-analyses more often follow APA 7. The author guide outranks this page.

Two journals that name the style in public author instructions

Psychological Science (updated 23 June 2026)

Manuscripts published in Psychological Science must follow the style of the Publication Manual of the American Psychological Association, 7th edition, with respect to handling of the order of manuscript sections, headings and subheadings, references, abbreviations, and symbols.

Journal of Nursing Education

Manuscripts should be prepared following the Publication Manual of the American Psychological Association, 7th edition, and spelling should reflect Dorland's Illustrated Medical Dictionary.

BMJ Author Hub

BMJ formats references using Vancouver style; references are sequentially numbered within the text of the main document and match the reference list at the end of the article.

Typical venue, not a substitute for the author guide
Writing situation	Usual style	Why
BMJ family, Lancet, NEJM, most ICMJE-following journals	Vancouver family	Numbered references in citation order; confirm parentheses vs superscripts vs brackets.
JAMA Network titles	AMA 11, not generic Vancouver	Superscripts and a 3-author et al. cutoff. See AMA vs Vancouver.
Clinical trial, case report, biomedical basic science	Vancouver	Compact numbers keep methods sentences readable.
Psychological Science and most psychology journals	APA 7	APS requires the Publication Manual, 7th ed., on invited revisions and finals.
Journal of Nursing Education and many nursing programs	APA 7	Healio's JNE instructions name APA 7 and an alphabetical reference list. See the nursing citation guide.
Health psychology or health communication thesis	Usually APA 7	The committee is reading an author–date literature.
Electrical or computer engineering	IEEE, not Vancouver	A different numbered family. See IEEE vs APA.

Use Vancouver when

The journal's Instructions for Authors name ICMJE, Uniform Requirements, NLM, or Vancouver.
You are writing a clinical trial, case report, or biomedical systematic review for a medical journal.
The source list is heavy with MEDLINE-abbreviated journals, PubMed PMIDs, and NLM-style DOIs.
Your medical school's research-methods course or thesis guide names Vancouver rather than APA.

Use APA 7 when

The course or journal is in psychology, education, nursing, occupational therapy, or another behavioral field.
The assignment sheet says APA, even if the topic is clinical.
You need narrative citations that keep authors visible ("Grady et al. (2019) found…").
The paper studies health behavior, patient education, or communication rather than a drug or device trial.

Failure Modes Students Actually Hit

Calling JAMA "Vancouver." JAMA Network journals use AMA 11. The numbered idea is shared; the author cutoff, italics, and in-text mark are not.
IEEE brackets in a medical paper. Vancouver's official ICMJE mark is (1). Square brackets on the line are IEEE unless that journal (for example a BMJ title) asked for them.
Semicolons between Vancouver authors. NLM samples separate names with commas: Halpern SD, Ubel PA, Caplan AL. Semicolons belong in other numbered styles, not here.
Requiring an issue number in every Vancouver entry. NLM says the month and issue are optional when the journal paginates continuously through the volume.
Abbreviating journal titles in APA. APA 7 wants The New England Journal of Medicine, not N Engl J Med.
AMA's 3-author et al. cutoff in a generic Vancouver list. ICMJE/NLM samples list six names, then et al. BMJ house style is stricter (first three). Follow the journal you are submitting to.
Adding a source in the middle of a Vancouver draft. Every later number has to move. A reference manager (Zotero, EndNote, BibTeX) is the fix; hand-renumbering is how (7) points at the wrong paper.
Writing `doi:` in APA, or `https://doi.org/` in Vancouver. Keep each style's DOI punctuation.
Mixing an alphabetical APA list with numbered in-text citations. Pick one system for the whole paper.
Citing a retracted paper as if it were current. ICMJE treats PubMed as the authority for MEDLINE retractions. Check before you lock the numbered list.

Common Mistakes

Guessing the MEDLINE abbreviation. Look it up in the NLM Catalog. JAMA stays JAMA; New England Journal of Medicine becomes N Engl J Med.
APA ampersand. Use & in parenthetical citations and in the reference list; use and in a narrative citation.
Treating Vancouver page spans like APA. NLM often writes 284-7; APA 7 writes 284–287 with an en dash.
Putting a city on an APA book. APA 7 dropped publisher location. NLM still wants St. Louis: Mosby; 2002.
Citing a database instead of the article when a DOI exists. In APA 7 the DOI replaces the database name.
Treating a preprint as a published article. ICMJE requires the citation to say it is a preprint. NLM sample 34 prints [Preprint] after the identifier.
Using a fabricated example from a random website. If you cannot verify the article, use a labelled official sample.

Frequently Asked Questions

Which citation style is more common in medical school, Vancouver or APA?: Clinical courses and most biomedical journals teach a Vancouver-family numbered style. Behavioral-science, nursing, and some public-health courses in the same school often require APA 7. Ask the syllabus; do not assume the MD program and the nursing program share a handbook.
Can I use APA for a clinical research paper?: Only if the target journal or your committee says so. Most clinical journals follow ICMJE and want numbered Vancouver-family references. A nursing or health-psychology journal is the usual case where APA 7 is required instead — Journal of Nursing Education names the APA 7th edition and an alphabetical list.
Is Vancouver the same as AMA or IEEE?: No. They share a numbered in-text idea and almost no punctuation you can copy. AMA 11 is the JAMA Network house style (superscripts; first 3 authors plus et al. when there are more than 6). IEEE uses [1] on the line and engineering abbreviations. Vancouver is ICMJE policy plus NLM bibliographic recipes.
Do Vancouver citations use parentheses, brackets, or superscripts?: ICMJE's published sentence is Arabic numerals in parentheses: (1). BMJ Author Hub then asks for square brackets or superscripts, and reserves parentheses for in-line lists. Check the Instructions for Authors and stay consistent. Do not mix marks in one manuscript.
How do Vancouver and APA use et al. differently?: Vancouver / NLM samples: in the reference list, print six names, then et al. APA 7: in every in-text citation, three or more names become first-plus-et-al.; in the reference list, print up to 20 names before an ellipsis. A journal may tighten Vancouver further — BMJ Author Hub asks for the first three names, then et al.
Do both styles require a DOI?: If the work has a DOI, include it in both. NLM writes doi: 10.1136/bmj.a2752 and may add PMID/PMCID. APA 7 writes https://doi.org/10.1136/bmj.a2752 and does not put a period after the URL. Do not add a retrieval date just because the article is online.
Does Vancouver require issue numbers?: Not always. NLM sample 1 shows the full form with month and issue (2002 Jul 25;347(4):284-7) and an optional form that omits them when pagination runs through the volume (2002;347:284-7). If the journal's own samples include the issue, include it.
How do I check that a Vancouver number does not point at a retracted paper?: ICMJE says you are responsible for verifying references in PubMed or the original source, and that PubMed is the authority for MEDLINE retractions. Search PubMed for Retracted publication [pt], or use PubMed's retracted-publication list, before you freeze the numbered list.
Can I cite ChatGPT or another AI tool as a source?: Not as a primary source under ICMJE: "Referencing AI-generated material as the primary source is not acceptable." The January 2026 Recommendations also say chatbots cannot be authors, and that Methods must name the tool, version, and prompts if AI conducted part of the study. APA 7 treats a chat as a software/tool citation or, when the output is unrecoverable, as a personal communication.

Pick one style, then generate the entries

Decide Vancouver or APA before you build the list. Use the Vancouver or APA generator for individual entries, or the compact side-by-side if you only need a restyle check. Then open the journal's author instructions — superscripts, author cutoffs, and DOI punctuation are the rows generators miss.

Vancouver citation generator APA citation generator APA vs Vancouver comparison table